ULNRC-06341, Callaway Plant Unit 1 - Enclosure 4 - 2015 Annual Report (Include 2014 Form 10-K)

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Callaway Plant Unit 1 - Enclosure 4 - 2015 Annual Report (Include 2014 Form 10-K)
ML16348A378
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Site: Callaway Ameren icon.png
Issue date: 12/13/2016
From:
Ameren Missouri, Union Electric Co
To:
Office of Nuclear Security and Incident Response, Division of Security Operations
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References
ULNRC-06341
Download: ML16348A378 (185)


Text

Enclosure 4 to ULNRC-06341

2015 ANNUAL REPORT (filed 2/26/2016 includes 2014 FORM 10-K)

AMEREN l 2015 Annual Report and Form 10-K2015 ANNUAL REPORTP.O. Box 66149 l St. Louis, Missouri 63166-6149 AMEREN.COM On the cover: This portion of the $1.4 billion Illinois Rivers Transmission Project near Champaign, Illinois, is expected to enter service in the fall of 2016. On the back cover: The natural gas storage eld in Lincoln, Illinois, ensures that natural gas is safely and reliably delivered to customers.

SI1506_AmerenAR_COVER.indd A-C SI1506_AmerenAR_COVER.indd A-C 2/26/16 9:01 AM 2/26/16 9:01 AM nancial highlights Ameren Consolidated In millions, except per share amounts and as notedYears ended Dec. 31 Results of Operations Operating revenues$6,098$6,053$5,838 Operating expenses$4,839$4,799$4,654 Operating income$1,259$1,254$1,184 Net income attributable to common shareholders from continuing operations

$579$587$512 Common Stock Data Continuing operations earnings per diluted share$2.38$2.40$2.10 Dividends per common share$1.655$1.61$1.60 Dividend yield (year-end) 3.9%3.6%4.4%Market price per common share (year-end closing)$43.23$46.13$36.16 Shares outstanding

- basic (weighted average)242.6 242.6 242.6Total market value of common shares (year-end)

$10,488$11,191$8,772 Book value per common share$28.63$27.67$26.97 Balance Sheet Data Property and plant, net$18,799$17,424$16,205Total assets$23,640$22,289$20,907 Long-term debt obligations, excluding current maturities

$6,880$6,085$5,475 Capitalization Ratios Common equity 48.3%48.8%50.2%Preferred stock 1.0%1.0%1.1%Debt, net of cash 50.7%50.2%48.7%Operating Data (Continuing)

Electric sales (kilowatt-hours) 79,092 79,955 80,003 Natural gas sales (decatherms in thousands) 182,927 202,810 195,266 Generation output (kilowatt-hours) 42,424 43,474 43,213 Electric customers 2.4 2.4 2.4 Natural gas customers 0.9 0.9 0.9 2015 2014 2013 GAAP to Core Earnings Reconciliation GAAP earnings per diluted share$2.59$2.40$1.18 Exclude results from discontinued operations (0.21)-0.92 Exclude provision for discontinuing pursuit of a license for a second nuclear unit at the Callaway Energy Center (included in continuing operations) 0.18--Core earnings per diluted share$2.56$2.40$2.10 COMMON STOCK AND DIVIDEND INFORMATIONAmeren's common stock is listed on the New York Stock Exchange (ticker symbol: AEE). Ameren began trading on Jan. 2, 1998, following the merger of Union Electric Company and CIPSCO Inc. on Dec. 31, 1997. Ameren common shareholders of record totaled 52,277 on Jan. 29, 2016. The following table provides the price ranges, closing prices and dividends declared per Ameren common share for each quarter of 2015 and 2014.ANNUAL MEETING The annual meeting of Ameren Corporation shareholders will convene at 10:30 a.m. (CDT) Thursday, April 28, 2016, at the Peoria Civic Center, 201 SW Jefferson Avenue, Peoria, Illinois 61602. The annual shareholder meetings of Ameren Illinois Company and Union Electric Company will be held at the same time.DRPLUS Any person of legal age or entity, whether or not an Ameren shareholder, is eligible to participate in DRPlus, Ameren's dividend reinvestment and stock purchase plan.Participants may:ł Make cash investments by check or automatic direct debit from their bank accounts to purchase Ameren common stock, up to a maximum of $360,000 annually;ł Reinvest their dividends in Ameren common stock (the minimum dividend reinvestment requirement is 10% per share); and ł Place Ameren common stock certificates in safekeeping and receive regular account statements.

For more information about DRPlus, you may obtain a prospectus from Ameren's Investor Services representatives.

DIRECT DEPOSIT OF DIVIDENDS All registered Ameren common and Ameren Illinois Company and Union Electric Company preferred shareholders may have their cash dividends automatically deposited to their bank accounts.

This service gives shareholders immediate access to their dividend on the dividend payment date and eliminates the possibility of lost or stolen dividend checks.CORPORATE GOVERNANCE DOCUMENTS Ameren makes available, free of charge through its website (Ameren.com), the charters of the Board of Directors' Audit and Risk Committee, Finance Committee, Human Resources Committee, Nominating and Corporate Governance Committee and Nuclear Oversight and Environmental Committee.

Also available on Ameren's website are its corporate governance guidelines, policy regarding nominations of directors, policy regarding communications to the Board of Directors, policy and procedures with respect to related person transactions, code of business conduct (referred to as the "Principles of Business Conduct")

and code of ethics for principal executive and senior nancial ofcers. These documents are also available in print, free of charge upon written request, from the Ofce of the Secretary, Ameren Corporation, P.O. Box 66149, Mail Code 1370, St. Louis, Missouri 63166-6149.

Ameren also makes available, free of charge through its website, the company's annual reports on SEC Form 10-K, quarterly reports on SEC Form 10-Q and its current reports on SEC Form 8-K, including any chief executive ofcer and chief nancial ofcer certications required to be led with the Securities and Exchange Commission.

ONLINE STOCK ACCOUNT ACCESSAmeren's website (Ameren.com) allows registered shareholders to access their account information online. Shareholders may securely change their reinvestment options, view account summaries, receive DRPlus statements and more through the website. This is a free service.INVESTOR SERVICESAmeren's Investor Services representatives are available to help you each business day from 8 a.m. to 4 p.m. (Central Time). Please write or call: Ameren Services Company, Investor ServicesP.O. Box 66887 St. Louis, Missouri 63166-6887 314.554.3502 or 800.255.2237

invest@ameren.com TRANSFER AGENT, REGISTRAR AND PAYING AGENT The Transfer Agent, Registrar and Paying Agent for Ameren common stock and Ameren Illinois Company and Union Electric Company preferred stock is Ameren Services Company.investor information Ameren Corporation One Ameren Plaza l 1901 Chouteau Avenue l St. Louis, Missouri 63103 l 314.621.3222 AEE 2015 Quarter Ended March 31 June 30 Sept.30 Dec.31 High$46.81$43.00$43.85$44.71 Low$40.51$37.26$37.55$41.33 Close$42.20$37.68$42.27$43.23 Dividends Declared 41 ¢41 ¢41 ¢42.5 ¢AEE 2014 Quarter Ended March 31 June 30 Sept.30 Dec.31 High$42.24$41.92$40.96$48.14 Low$35.22 $37.67 $36.65$38.25 Close$41.20$40.88$38.33$46.13 Dividends Declared 40 ¢40 ¢40 ¢41 ¢SI1506_AmerenAR_COVER.indd D-F SI1506_AmerenAR_COVER.indd D-F 3/1/16 9:42 AM 3/1/16 9:42 AM My fellow shareholders:As one of the leading energy providers in the Midwest, we at Ameren recognize our tremendous responsibility to customers, shareholders, co-workers and the communities we serve. Indeed, this responsibility is embedded in our company's vision - Leading the Way to a Secure Energy Future - and our mission - To Power the Quality of Life. I am fortunate to work with 8,500 people who see Ameren's vision and mission as more than words on paper, but rather as a daily call to action. Simply put, my co-workers take this responsibility to heart.Safe, reliable energy is the bedrock of our nation's economic prosperity and standard of living, and millions of people in Illinois and Missouri depend on Ameren to deliver. That's why the corporate strategy we have developed, and continue to successfully

execute, is built on our vision and mission. In executing this strategy, our actions are having a meaningful, positive impact for our stakeholders. The following discussion

highlights how the actions we took in 2015 are helping us achieve our vision and mission today and in the future.LETTER FROM THE CEOWARNER L. BAXTER Chairman, President and CEOmaking an impact AMEREN'S STRATEGY is to invest in rate-regulated energy infrastructure which, when coupled with relentlessly improving operating performance and advocating for responsible energy policies, will deliver superior customer and shareholder value.AMEREN CO RP ORATI O N 201 5 ANNUAL REPORT 1 SI1506_AmerenAR.indd 1 SI1506_AmerenAR.indd 1 2/26/16 9:03 AM 2/26/16 9:03 AM In 2015 we invested nearly $2 billion to: Improve electric and natural gas reliability and security by modernizing our infrastructure.

Enhance access to cleaner, renewable energy by strengthening our nation's electric transmission system. Increase our ability to meet customers' future energy needs by installing new technologies, especially in Illinois, where constructive policies support investments.

These investments are producing results. Our customers enjoy top-tier reliability with some of the lowest electric rates in the country - below both the Midwest and national averages. Those who participated in our comprehensive energy efciency programs, as well as new payment and communication options, have gained added convenience and greater control over their energy bills. In addition, more than 160,000 new advanced electric meters were installed and over 70,000 gas meters upgraded for our Illinois customers in 2015. And in Missouri we are generating cleaner energy with lower environmental emissions.

CustomersMy co-workers understand that we are in the customer business, not just the utility business. It is important to understand what matters to our customers and how we can deliver the value they expect.Our customers tell us they want safe, secure and reliable energy - and their expectations are rising. They want cleaner energy. They want energy that is reasonably priced. And they want greater options to manage their energy bills.Ameren is focused on achieving results that matter in all of these areas.¢/KWH 0 AMEREN IL AMEREN MO CHICAGO MINNEAPOLIS U.S. AVERAGE DETROIT BOSTON NEW YORK 5 10 15 25 20 8.49 10.26 12.56 12.33 12.87 14.22 20.85 27.61 MIDWEST AVERAGE 12.36 ATLANTA 11.99 SAN FRANCISCO 16.78REASONABLY PRICED ELECTRICITY IMPROVING RELIABILITYOUTAGE FREQUENCYAmeren's electric distribution reliability performance has improved, as measured by the System Average Interruption Frequency Index. This important industry benchmark shows how we have reduced the total number of interruptions per customer served per year.The electricity delivered by Ameren Missouri and Ameren Illinois remains competitively priced. This is particularly

important for low- and xed-income customers and for businesses seeking to launch or expand.C0 2 EMISSIONS:

24%*S0 2 EMISSIONS:

42%*AVERAGE RESIDENTIAL ELECTRIC PRICES (Edison Electric Institute "Typical Bills and Average Rates Report" for 12 months ending June 2015)*Ameren Missouri carbon dioxide and sulfur dioxide emissions for calendar year 2015 compared to 2011 REDUCING EMISSIONS Ameren has 2.4 million electric and 900,000 natural gas customers in communities across Illinois and Missouri.

1.0 0.8 1.2 1.4 2005 2007 2009 2011 2013 2015 BETTER 2 SI1506_AmerenAR.indd 2 SI1506_AmerenAR.indd 2 2/26/16 8:47 AM 2/26/16 8:47 AM AMEREN ILLINOISProjects to boost the reliability of natural gas and electric infrastructure are reducing outages, which saves customers more than $47 million per year on average, in addition to creating new jobs. Since the modernization program began in 2012, electric system projects such as the installation of storm-hardened utility poles, outage detection technology and stronger power lines have resulted in a 17 percent improvement in reliability. When customers do experience an outage, Ameren Illinois is restoring power 18 percent faster, on average, than in previous years. The state of Illinois is rated No. 2 in the nation by the National Grid Modernization Index for creating an environment that encourages such investment.

AMEREN TRANSMISSIONConstruction of the $1.4 billion Illinois Rivers Transmission Project remains on schedule, with expected completion in 2019. Ameren Transmission Company of Illinois also has received a Certi cate of Public Convenience and Necessity from the Illinois Commerce Commission authorizing construction of the $150 million Spoon River Transmission Project. These projects and others are directly aligned with Amerens goals of providing reliable, ef cient and environmentally responsible energy. These grid modernization projects also are creating jobs.AMEREN MISSOURIAmeren Missouri continues to make signi cant infrastructure investments as part of its transition to cleaner energy sources and to ensure reliability. Thats why emissions are down and why reliability is among the top 25 percent in the nation. Ameren Missouri also received the J.D. Power award for the highest ranking among large, Midwest utilities for overall customer satisfaction with business electric service customers.

LETTER FROM THE CEOAs part of the $1.4 billion Illinois Rivers Transmission Project, workers on Jan. 7, 2016, secure in place nal parts of a lattice tower, one of six such towers needed for a Mississippi River crossing connecting Missouri and Illinois line segments near Quincy, Illinois.AME A REN CO RP ORATRAT N ION ION 201 20 20 2 5 A NNU NN N N AL REPORT 3 SI1506_AmerenAR.indd 3

SI1506_AmerenAR.indd 3 2/26/16 8:47 AM 2/26/16 8:47 AM Shareholders Driven by the successful execution of our strategy, Ameren's stock has outperformed the broader utility indices over the last three years. As the chart below indicates, shareholders have seen a total shareholder return of nearly 60 percent over the three-year

period from Dec. 31, 2012, through Dec. 31, 2015, performance that put us among the leaders in the utility industry.

During this same period, our core earnings per share grew by a total of 22 percent.

At the same time, we have increased our dividend rate twice, in total by 6.25 percent to an annualized level of $1.70 per share, indicative of con dence in our strategy.

We remain focused on successfully executing

our strategy, including allocating more capital to areas of o u r business with constructive regulatory frameworks, maintaining disciplined

cost management and strongly advocating

for responsible energy policies at the state and federal levels, to deliver superior long-term value for you, our shareholders.This strategic focus also has strengthened us nancially and helped improve our credit ratings, enabling us to access debt at competitive rates.ANNUALIZED DIVIDEND 6.25% since 2013 OUTPERFORMING OUR PEERS: Three-Year Total Cumulative Shareholder Return (12.31.12 through 12.31.15)

S&P 500 UTILITIES AMEREN$1.25$1.75$1.60$1.64 $1.70 $1.00$1.50$2.00 CORE EARNINGS PER DILUTED SHARE 22% since 2013 2013 2014 2015$2.10$2.56 $1.00$1.50$2.00$2.50$3.00$2.40 PHILADELPHIA UTILITY INDEX 20%30%40%50%60%39%34%60%12.31.1312.31.1412.31.15*See inside front cover for a reconciliation of GAAP to core earnings per diluted share.4 SI1506_AmerenAR.indd 4 SI1506_AmerenAR.indd 4 2/26/16 8:48 AM 2/26/16 8:48 AM Community At Ameren, we believe we are only as strong as the communities we serve. And we are making an impact in our service territories through employee volunteerism, investment and philanthropic support.For example, last fall we announced a comprehensive $2.5 million community initiative

related to child well-being, education, energy assistance and job readiness for the greater St. Louis area as a direct response to recommendations of the Ferguson Commission.

My co-workers pledged $1.8 million to the United Way in 2015, to benet more than 50 United Way chapters in Missouri and Illinois.

In fact, since 1971, Ameren and its employees have provided nearly

$50 million in support of United Way of Greater St. Louis, in addition to long-term support of other United Way chapters in Missouri and Illinois.

My co-workers also generously volunteered

thousands of hours to local organizations to help meet growing needs across the hundreds of communities we serve.We are humbled and honored to have been part of communities in Missouri and Illinois for over 100 years. Our passion and commitment

to build stronger, healthier and more inclusive

communities will not waver.Co-WorkersAt Ameren, our people are our greatest asset. As a result, its important that we make investments in safety, training, wellness and diversity to improve their work and personal lives. These efforts are making an impact.Safety is the foundation for everything we do. Our relentless focus on safety and training has resulted in meaningf ul improvements in our overall safety performance. Similarly, our focus on diversity and wellness resulted in numerous awards in 2015, including those listed on the next page. Ameren employees can be proud of these accomplishments.

My co-workers across the company are also actively engaged in a host of continuous improvement and innovation initiatives to leverage rapidly changing technologies.

LETTER FROM THE CEO The Ameren Cares initiative works to improve the quality of life through partnerships with nonpro t organizations.

And at the core of nearly every nonpro t organization are its volunteers.

Employees who volunteer make a difference in the lives of individuals and families throughout our service territories in Missouri and Illinois. In addition, Ameren provides nancial support for nonpro t organizations through the Ameren Corporation Charitable Trust.SI1506_AmerenAR.indd 5 SI1506_AmerenAR.indd 5 3/4/16 8:37 AM 3/4/16 8:37 AM april 28 10:30 A.M. CDT PLEASE JOIN US AT THE ANNUAL MEETING OF SHAREHOLDERS PEORIA CIVIC CENTER 201 SW Jefferson Ave. Peoria, Illinois 61602WARNER L. BAXTER Chairman, President and Chief Executive Of cer March 1, 2016 Simply put, millions of people and thousands of businesses in Illinois and Missouri are counting on our people for safe, dependable energy, 365 days a year. This compels us to keep our workforce safe and well; to prepare them to perform under challenging

conditions; and to provide training and opportunities

for both personal and professional growth. We must nurture the next generation of talent in order to sustain our company, drive innovation and meet our customers future energy needs and expectations.

In closing, I want to reiterate that Ameren is focused on executing our strategy to deliver superior value to you our shareholders, our customers and the communities we serve. Electricity and natural gas services are critical for our modern world. With such a vital purpose, Ameren strives to keep energy safe, reliable, cleaner and reasonably priced for all. We are always improving.

Always innovating.

Always looking to tomorrow.

Always making an impact.

And always focused on delivering on our vision of Leading the Way to a Secure Energy Future and our mission To Power the Quality of Life.TOP 100 MILITARY FRIENDLY EMPLOYERS G.I. Jobs Magazine 2015 HEALTHIEST EMPLOYERSSt. Louis Business Journal TOP UTILITY IN THE UNITED STATES FOR DIVERSITY & INCLUSIONDiversityInc BEST EMPLOYERS LIST FOR 2015Forbes TOP 50 EMPLOYERWoman Engineer Magazine SI1506_AmerenAR.indd 6 SI1506_AmerenAR.indd 6 3/1/16 9:39 AM 3/1/16 9:39 AM From left to right: MARK C. LINDGREN Senior Vice President, Corporate Communications and Chief Human Resources Of cer, Ameren ServicesMARY P. HEGER Senior Vice President and Chief Information Of cer, Ameren Services MARTIN J. LYONS, JR. Executive Vice President and Chief Financial Of cer, Ameren Corporation; and Chairman and President, Ameren Services RICHARD J. MARK Chairman and President, Ameren IllinoisWARNER L. BAXTER Chairman, President and Chief Executive Of cer, Ameren Corporation MICHAEL L. MOEHN Chairman and President, Ameren Missouri MAUREEN A. BORKOWSKI Chairman and President, Ameren Transmission

Company and Ameren Transmission

Company of Illinois MARK C. BIRK Senior Vice President, Corporate Safety, Planning and Operations

Oversight, Ameren ServicesFADI M. DIYA Senior Vice President and Chief Nuclear Of cer, Ameren MissouriGREGORY L. NELSON Senior Vice President, General Counsel and Secretary , Ameren CorporationLeadership Team AMEREN'S EXECUTIVE LEADERSHIP TEAM A MEREN CO RP O ATRAT I O N201201 5 A 5 A NNU AL A REP O RT 7 SI1506_AmerenAR.indd 7 SI1506_AmerenAR.indd 7 2/26/16 9:58 AM 2/26/16 9:58 AM AMEREN CORPORATION AND SUBSIDIARIES OFFICERS Ajay K. Arora*Vice President, Environmental Services and Generation Resource Planning, Ameren Services Lynn M. Barnes*Vice President, Business Planning and Controller, Ameren Missouri Krista G. Bauer*Assistant Vice President, Corporate Human Resources, Ameren Services S. Mark BrawleyVice President and Controller, Ameren Corporation Kendall D. Coyne*Vice President, Tax, Ameren Services Kevin A. DeGraw*Vice President, Corporate Operations Oversight and Continuous Improvement, Ameren Services Sharon Harvey Davis*Vice President, Diversity and Inclusion and Chief Diversity Of cer, Ameren ServicesTimothy E. Herrmann*Site Vice President, Callaway Energy Center, Ameren Missouri Christopher A. Iselin*Senior Vice President, Power Operations and Energy Management, Ameren Missouri

Stephen M. Kidwell*Vice President, Corporate Planning, Ameren Services Geralynn M. Lord*Vice President, Corporate Communications, Ameren Services Ryan J. MartinVice President and Treasurer, Ameren Corporation Michael G. Mueller*Vice President, Economic and Technology Development, Ameren Services Craig D. Nelson*Senior Vice President, Regulatory Affairs and Financial Services, Ameren Illinois Stan E. Ogden*Vice President, Customer Service and Metering Operations, Ameren IllinoisTara K. Oglesby*Vice President, Customer Experience, Ameren Missouri Ronald D. Pate*Senior Vice President, Operations and Technical Services, Ameren Illinois Joseph M. Power*Vice President, Federal Legislative and Regulatory Affairs, Ameren ServicesDarryl T. Sagel*Assistant Vice President, Corporate Development, Ameren Services Shawn E. Schukar*Senior Vice President, Transmission Business Development, Ameren Transmission Company and Ameren Transmission Company of Illinois Theresa A. ShawVice President, Internal Audit, Ameren Corporation James A. Sobule*Vice President and Deputy General Counsel, Ameren Services Bruce A. SteinkeSenior Vice President, Finance and Chief Accounting Of cer, Ameren CorporationDavid N. Wakeman*Senior Vice President, Customer Operations, Ameren MissouriDennis W. Weisenborn*Vice President, Corporate Safety, Supply Services and Chief Procurement Of cer, Ameren Services Raymond M. Wiesehan*Vice President, Corporate Security and Crisis Management, Ameren Services D. Scott Wiseman*Vice President, External Affairs, Ameren IllinoisWarren T. Wood*Vice President, External Affairs and Communications, Ameren MissouriBOARD OF DIRECTORS Warner L. Baxter Chairman, President and Chief Executive Ofcer, Ameren Corporation Catherine S. Brune Retired President, Allstate Protection Eastern Territory of Allstate Insurance Company

Audit and Risk Committee; Nominating and Corporate

Governance Committee J. Edward Coleman Former Chairman and Chief Executive Ofcer, Unisys Corporation Audit and Risk Committee; Nuclear Oversight and Environmental Committee Ellen M. Fitzsimmons Executive Vice President of Law and Public Affairs, General Counsel and Corporate Secretary, CSX Corporation Audit and Risk Committee; Nominating and Corporate

Governance Committee Rafael Flores Former Senior Vice President and Chief Nuclear Ofcer, Luminant Nominating and Corporate

Governance Committee;

Nuclear Oversight and Environmental CommitteeWalter J. Galvin Retired Vice Chairman and Chief Financial Ofcer, Emerson Electric Co.

Audit and Risk Committee; Finance Committee; Lead Director Richard J. Harshman Chairman, President and Chief Executive Ofcer, Allegheny Technologies Incorporated Human Resources Committee; Nuclear Oversight and Environmental CommitteeDr. Gayle P. W. Jackson President and Chief Executive Ofcer, Energy Global, Inc.

Nominating and Corporate

Governance Committee;

Nuclear Oversight and Environmental Committee James C. Johnson Retired General Counsel, Loop Capital Markets LLC Human Resources Committee; Nuclear Oversight and Environmental Committee Steven H. Lipstein President and Chief Executive Ofcer, BJC HealthCare Finance Committee; Human Resources Committee Stephen R. Wilson Retired Chairman, President and Chief Executive Ofcer, CF Industries Holdings, Inc.

Finance Committee; Human Resources CommitteeJack D. Woodard Retired Executive Vice President and Chief Nuclear Ofcer, Southern Nuclear Operating Company, Inc.

Nominating and Corporate

Governance Committee;

Nuclear Oversight and Environmental CommitteeThe of cers also include the Ameren Executive Leadership Team on page 7. The of cer and Board of Directors listings are as of March 1, 2016.*Of cer of an Ameren Corporation subsidiary only.

8 SI1506_AmerenAR.indd 8 SI1506_AmerenAR.indd 8 3/1/16 11:00 AM

3/1/16 11:00 AM UNITEDSTATESSECURITIESANDEXCHANGECOMMISSIONWashington,D.C.20549FORM10-K(X)AnnualreportpursuanttoSection13or15(d)oftheSecuritiesExchangeActof1934forthefiscalyearendedDecember31,2015.

OR()TransitionreportpursuanttoSection13or15(d)oftheSecuritiesExchangeActof1934forthe transitionperiodfromto.

Commission FileNumberExactnameofregistrantasspecifiedinitscharter; StateofIncorporation; AddressandTelephoneNumberIRSEmployer IdentificationNo.

1-14756AmerenCorporation 43-1723446(MissouriCorporation) 1901ChouteauAvenue St.Louis,Missouri63103 (314)621-3222 1-2967UnionElectricCompany 43-0559760(MissouriCorporation) 1901ChouteauAvenue St.Louis,Missouri63103 (314)621-3222 1-3672AmerenIllinoisCompany 37-0211380(IllinoisCorporation) 6ExecutiveDrive Collinsville,Illinois62234 (618)343-8150SecuritiesRegisteredPursuanttoSection12(b)oftheAct:ThefollowingsecurityisregisteredpursuanttoSection12(b)oftheSecuritiesExchangeActof1934andislistedontheNewYorkStockExchange:

RegistrantTitleofeachclassAmerenCorporationCommonStock,$0.01parvaluepershareSecuritiesRegisteredPursuanttoSection12(g)oftheAct:

RegistrantTitleofeachclassUnionElectricCompanyPreferredStock,cumulative,noparvalue,statedvalue$100pershareAmerenIllinoisCompanyPreferredStock,cumulative,$100parvaluepershare DepositaryShares,eachrepresentingone-fourthofashare of6.625%PreferredStock,cumulative,$100parvalueper

share Indicatebycheckmarkifeachregistrantisawell-knownseasonedissuer,asdefinedinRule405oftheSecuritiesAct.AmerenCorporationYes(X)No()UnionElectricCompanyYes()No(X)AmerenIllinoisCompanyYes(X)No()IndicatebycheckmarkifeachregistrantisnotrequiredtofilereportspursuanttoSection13orSection15(d)oftheAct.

AmerenCorporationYes()No(X)UnionElectricCompanyYes()No(X)AmerenIllinoisCompanyYes()No(X)Indicatebycheckmarkwhethertheregistrants:(1)havefiledallreportsrequiredtobefiledbySection13or15(d)oftheSecuritiesExchangeActof1934duringthepreceding12months(orforsuchshorterperiodthattheregistrantwasrequiredtofilesuchreports),and(2)havebeensubjecttosuchfilingrequirementsforthepast90days.AmerenCorporationYes(X)No()UnionElectricCompanyYes(X)No()AmerenIllinoisCompanyYes(X)No()Indicatebycheckmarkwhethereachregistranthassubmittedelectronicallyandpostedonitscorporatewebsite,ifany,everyInteractiveDataFilerequiredtobesubmittedandpostedpursuanttoRule405ofRegulationS-T(§232.405ofthis chapter)duringthepreceding12months(orforsuchshorterperiodthattheregistrantwasrequiredtosubmitandpostsuch

files).AmerenCorporationYes(X)No()UnionElectricCompanyYes(X)No()AmerenIllinoisCompanyYes(X)No()IndicatebycheckmarkifdisclosureofdelinquentfilerspursuanttoItem405ofRegulationS-K(§229.405ofthischapter)isnotcontainedherein,andwillnotbecontained,tothebestofeachregistrant'sknowledge,indefinitiveproxyor informationstatementsincorporatedbyreferenceinPartIIIofthisForm10-KoranyamendmenttothisForm10-K.AmerenCorporation (X)UnionElectricCompany (X)AmerenIllinoisCompany (X)Indicatebycheckmarkwhethereachregistrantisalargeacceleratedfiler,anacceleratedfiler,anon-acceleratedfilerorasmallerreportingcompany.Seedefinitionsof"largeacceleratedfiler,""acceleratedfiler,"and"smallerreportingcompany"in Rule12b-2oftheExchangeAct.

Large Accelerated Filer Accelerated Filer Non-accelerated Filer Smaller Reporting CompanyAmerenCorporation(X)()()()UnionElectricCompany()()(X)()AmerenIllinoisCompany()()(X)()Indicatebycheckmarkwhethereachregistrantisashellcompany(asdefinedinRule12b-2oftheAct).AmerenCorporationYes()No(X)UnionElectricCompanyYes()No(X)AmerenIllinoisCompanyYes()No(X)

AsofJune30,2015,AmerenCorporationhad242,634,798sharesofits$0.01parvaluecommonstockoutstanding.Theaggregatemarketvalueofthesesharesofcommonstock(basedupontheclosingpriceofthecommonstockontheNewYorkStockExchangeonJune30,2015)heldbynonaffiliateswas$9,142,479,189.Thesharesofcommonstockoftheother registrantswereheldbyAmerenCorporationasofJune30,2015.Thenumberofsharesoutstandingofeachregistrant'sclassesofcommonstockasofJanuary29,2016,wasasfollows:AmerenCorporationCommonstock,$0.01parvaluepershare:242,634,798UnionElectricCompanyCommonstock,$5parvaluepershare,heldbyAmeren Corporation(parentcompanyoftheregistrant):

102,123,834AmerenIllinoisCompanyCommonstock,noparvalue,heldbyAmeren Corporation(parentcompanyoftheregistrant):

25,452,373DOCUMENTSINCORPORATEDBYREFERENCEPortionsofthedefinitiveproxystatementofAmerenCorporationandportionsofthedefinitiveinformationstatementsofUnionElectricCompanyandAmerenIllinoisCompanyforthe2016annualmeetingsofshareholdersareincorporatedby referenceintoPartIIIofthisForm10-K.ThiscombinedForm10-KisseparatelyfiledbyAmerenCorporation,UnionElectricCompany,andAmerenIllinoisCompany.Eachregistrantheretoisfilingonitsownbehalfalloftheinformationcontainedinthisannualreportthatrelatesto suchregistrant.Eachregistrantheretoisnotfilinganyinformationthatdoesnotrelatetosuchregistrant,andthereforemakes norepresentationastoanysuchinformation.

TABLEOFCONTENTS PageGLOSSARYOFTERMSANDABBREVIATIONS.......................................................1Forward-lookingStatements.....................................................................4PARTIItem1.Business.........................................................................5 General......................................................................5BusinessSegments.............................................................6RatesandRegulation...........................................................6TransmissionandSupplyofElectricPower..........................................10PowerGeneration..............................................................11NaturalGasSupplyforDistribution.................................................13IndustryIssues................................................................13OperatingStatistics.............................................................15AvailableInformation...........................................................16Item1A.RiskFactors......................................................................17Item1B.UnresolvedStaffComments..........................................................24Item2.Properties........................................................................25Item3.LegalProceedings..................................................................26Item4.MineSafetyDisclosures.............................................................27ExecutiveOfficersoftheRegistrants(Item401(b)ofRegulationS-K).....................................27PARTII Item5.MarketforRegistrants'CommonEquity,RelatedStockholderMatters,andIssuerPurchasesofEquity Securities

........................................................................

29Item6.SelectedFinancialData..............................................................31Item7.Management'sDiscussionandAnalysisofFinancialConditionandResultsofOperations...........31 Overview.....................................................................32ResultsofOperations...........................................................33LiquidityandCapitalResources...................................................45 Outlook......................................................................56RegulatoryMatters.............................................................60AccountingMatters.............................................................60EffectsofInflationandChangingPrices.............................................63Item7A.QuantitativeandQualitativeDisclosuresAboutMarketRisk..................................63Item8.FinancialStatementsandSupplementaryData............................................67SelectedQuarterlyInformation....................................................137Item9.ChangesinandDisagreementswithAccountantsonAccountingandFinancialDisclosure..........137Item9A.ControlsandProcedures.............................................................138Item9B.OtherInformation..................................................................138PARTIII Item10.Directors,ExecutiveOfficers,andCorporateGovernance....................................138Item11.ExecutiveCompensation.............................................................139Item12.SecurityOwnershipofCertainBeneficialOwnersandManagementandRelatedStockholder Matters..........................................................................

139Item13.CertainRelationshipsandRelatedTransactionsandDirectorIndependence.....................140Item14.PrincipalAccountingFeesandServices.................................................140PARTIV Item15.ExhibitsandFinancialStatementSchedules..............................................141 SIGNATURES.................................................................................146EXHIBITINDEX...............................................................................149Thisreportcontains"forward-looking"statementswithinthemeaningofSection21EoftheSecuritiesExchangeActof1934,asamended.Forward-lookingstatementsshouldbereadwiththecautionarystatementsandimportantfactorsundertheheading"Forward-lookingStatements."Forward-lookingstatementsareallstatementsotherthanstatementsofhistorical fact,includingthosestatementsthatareidentifiedbytheuseofthewords"anticipates,""estimates,""expects,""intends,"

"plans,""predicts,""projects,"andsimilarexpressions.

GLOSSARYOFTERMSANDABBREVIATIONSWeusethewords"our,""we"or"us"withrespecttocertaininformationthatrelatestoAmeren,AmerenMissouri,andAmerenIllinois,collectively.Whenappropriate,subsidiariesofAmerenCorporationarenamedspecificallyastheirvariousbusinessactivitiesarediscussed.2006IncentivePlan-The2006OmnibusIncentiveCompensationPlanprovidesforcompensatorystock-basedawardstoeligibleemployeesanddirectors.The2006 OmnibusIncentiveCompensationPlanwasreplaced prospectivelyfornewgrantsbythe2014IncentivePlan.

2014IncentivePlan-The2014OmnibusIncentiveCompensationPlan,whichbecameeffectiveinApril2014 andprovidesforcompensatorystock-basedawardsto eligibleemployeesanddirectors.

AER-AmerenEnergyResourcesCompany,LLC,aformerAmerenCorporationsubsidiarythatconsistedofnon-rate-regulatedoperations.InDecember2013,AERcontributed substantiallyallofitsassetsandliabilities,includingits ownershipinterestsinGenco,AERG,andMarketing Company,toNewAER.MedinaValleywasdistributedfrom AERtoAmereninMarch2013.

AERG-AmerenEnergyResourcesGeneratingCompany,aformerAERsubsidiarythatoperatedamerchantelectric generationbusinessinIllinois.InDecember2013,AERG wasincludedinthedivestitureofNewAERtoIPH.

FollowingtheNewAERdivestiture,AERGbecameIllinois PowerResourcesGenerating,LLC.

Ameren-AmerenCorporationanditssubsidiariesonaconsolidatedbasis.Inreferencestofinancingactivities, acquisitionactivities,orliquidityarrangements,Amerenis definedasAmerenCorporation,theparent.

AmerenCompanies-AmerenCorporation,AmerenMissouri,andAmerenIllinois,collectively,whichare individualregistrantswithintheAmerenconsolidatedgroup.

AmerenIllinoisorAIC-AmerenIllinoisCompany,anAmerenCorporationsubsidiarythatoperatesrate-regulated electricandnaturalgastransmissionanddistribution businessesinIllinois,doingbusinessasAmerenIllinois.

AmerenIllinoisisalsodefinedasafinancialreporting

segment.

AmerenIllinoisMerger-In2010,CILCOandIPmergedwithandintoCIPS,withthesurvivingcorporationrenamed AmerenIllinoisCompany.

AmerenMissouriorAMO-UnionElectricCompany,anAmerenCorporationsubsidiarythatoperatesarate-regulatedelectricgeneration,transmissionanddistribution businessandarate-regulatednaturalgastransmissionand distributionbusinessinMissouri,doingbusinessas AmerenMissouri.AmerenMissouriisalsodefinedasa financialreportingsegment.

AmerenServices-AmerenServicesCompany,anAmerenCorporationsubsidiarythatprovidessupportservicesto Amerenanditssubsidiaries.

AMIL-TheMISObalancingauthorityareaoperatedbyAmeren,whichincludestheloadofAmerenIllinoisand

ATXI.

AMMO-TheMISObalancingauthorityareaoperatedbyAmeren,whichincludestheloadandenergycentersof AmerenMissouri.

ARO-Assetretirementobligations.

ATXI-AmerenTransmissionCompanyofIllinois,anAmerenCorporationsubsidiarythatisengagedinthe constructionandoperationofelectrictransmissionassets.

Baseload-Theminimumamountofelectricpowerdeliveredorrequiredoveragivenperiodoftimeatasteady

rate.

Btu-Britishthermalunit,astandardunitformeasuringthequantityofheatenergyrequiredtoraisethetemperatureof onepoundofwaterbyonedegreeFahrenheit.

CCR-Coalcombustionresiduals,whichincludeflyash,bottomash,boilerslagandfluegasdesulfurization materialsgeneratedfromburningcoaltogenerate

electricity.

CILCO-CentralIllinoisLightCompany,aformerAmerenCorporationsubsidiarythatoperatedrate-regulatedelectric andnaturalgastransmissionanddistributionbusinessesin Illinois,beforetheAmerenIllinoisMerger.

CIPS-CentralIllinoisPublicServiceCompany,anAmerenCorporationsubsidiary,renamedAmerenIllinoisCompany upontheeffectivenessoftheAmerenIllinoisMerger,which operatesrate-regulatedelectricandnaturalgas transmissionanddistributionbusinessesinIllinois.

CleanPowerPlan-"CarbonPollutionEmissionGuidelinesforExistingStationarySources:ElectricUtilityGenerating Units,"anEPArulethatestablishesemissionguidelinesfor statestofollowindevelopingplanstoreduceCO 2emissionsfromexistingfossilfuel-firedelectricgenerating

units.

CO 2-Carbondioxide.

COL-Nuclearenergycentercombinedconstructionandoperatinglicense.

Coolingdegree-days-Thesummationofpositivedifferencesbetweentheaveragedailytemperatureanda 65-degreeFahrenheitbase.Thisstatisticisusefulasan indicatorofelectricitydemandbyresidentialand commercialcustomersforsummercooling.

CreditAgreements-TheIllinoisCreditAgreementandtheMissouriCreditAgreement,collectively.

CSAPR-Cross-StateAirPollutionRule,anEPArulethatrequiresstatesthatcontributetoairpollutionindown-wind statestolimitairemissionsfromfossilfuel-firedelectric generatingunits.

CT-Combustionturbineusedprimarilyforpeakingelectricgenerationcapacity.

Dekatherm-AstandardunitofenergyequivalenttoonemillionBtus.

DOE-DepartmentofEnergy,aUnitedStatesgovernment agency.

DRPlus-AmerenCorporation'sdividendreinvestmentanddirectstockpurchaseplan.

Dynegy-DynegyInc.

EEI-ElectricEnergy,Inc.,aformer80%-ownedGencosubsidiarythatoperatedmerchantelectricgeneration 1

energycentersandFERC-regulatedtransmissionfacilitiesinIllinois.InDecember2013,Genco'sownershipinterestin EEIwasincludedinthedivestitureofNewAERtoIPH.

EPA-EnvironmentalProtectionAgency,aUnitedStatesgovernmentagency.

ERISA-EmployeeRetirementIncomeSecurityActof1974,asamended.

ExchangeAct-SecuritiesExchangeActof1934,as amended.

FAC-Fueladjustmentclause,afuelandpurchasedpowercostrecoverymechanismthatallowsAmerenMissourito recoverorrefundthroughcustomerrates95%ofchanges innetenergycostsgreaterorlessthantheamountsetin baserateswithoutatraditionalrateproceeding,subjectto MoPSCprudencereviews.

FASB-FinancialAccountingStandardsBoard,arulemakingorganizationthatestablishesfinancial accountingandreportingstandardsintheUnitedStates.

FERC-FederalEnergyRegulatoryCommission,aUnitedStatesgovernmentagency.

FTRs-Financialtransmissionrights,financialinstrumentsthatspecifywhethertheholdershallpayorreceive compensationforcertaincongestion-relatedtransmission chargesbetweentwodesignatedpoints.

GAAP-GenerallyacceptedaccountingprinciplesintheUnitedStates.

Genco-AmerenEnergyGeneratingCompany,aformerAERsubsidiarythatoperatedamerchantelectricgeneration businessinIllinoisandheldan80%ownershipinterestin EEI.InDecember2013,Gencowasincludedinthe divestitureofNewAERtoIPH.FollowingtheNewAER divestiture,GencobecameIllinoisPowerGenerating

Company.

Heatingdegree-days-Thesummationofnegativedifferencesbetweentheaveragedailytemperatureanda 65-degreeFahrenheitbase.Thisstatisticisusefulasan indicatorofdemandforelectricityandnaturalgasforwinter heatingbyresidentialandcommercialcustomers.

IBEW-InternationalBrotherhoodofElectricalWorkers,alaborunion.

ICC-IllinoisCommerceCommission,astateagencythatregulatesIllinoisutilitybusinesses,includingAmeren IllinoisandATXI.

IEIMA-IllinoisEnergyInfrastructureModernizationAct,anIllinoislawthatestablishedaperformance-basedformula processfordeterminingelectricdeliveryservicerates.By itselectiontoparticipateinthisregulatoryframework, AmerenIllinoisisrequiredtomakeincrementalcapital expenditurestomodernizeitselectricdistributionsystem, meetperformancestandards,andcreatejobsinIllinois, amongotherrequirements.

IllinoisCreditAgreement-Ameren'sandAmerenIllinois'$1.1billionmultiyearseniorunsecuredcreditagreement.

TheagreementwasamendedandrestatedinDecember 2014andiscurrentlyscheduledtoexpireonDecember11, 2019.

IP-IllinoisPowerCompany,aformerAmerenCorporationsubsidiarythatoperatedrate-regulatedelectricandnatural gastransmissionanddistributionbusinessesinIllinois, beforetheAmerenIllinoisMerger.

IPA-IllinoisPowerAgency,astategovernmentagencythathasbroadauthoritytoassistintheprocurementof electricpowerforresidentialandsmallcommercial

customers.

IPH-IllinoisPowerHoldings,LLC,anindirectwhollyownedsubsidiaryofDynegy.

IRS-InternalRevenueService,aUnitedStatesgovernment agency.

ISRS-Infrastructuresystemreplacementsurcharge,whichisacostrecoverymechanismthatallowsAmerenMissouri torecovernaturalgasinfrastructurereplacementcosts fromutilitycustomerswithoutatraditionalrateproceeding.

IUOE-InternationalUnionofOperatingEngineers,alabor union.

Kilowatthour-Ameasureofelectricityconsumptionequivalenttotheuseof1,000wattsofpoweroverone

hour.

LIUNA-Laborers'InternationalUnionofNorthAmerica,alaborunion.

MarketingCompany-AmerenEnergyMarketingCompany,aformerAERsubsidiarythatmarketedpowerforGenco, AERG,andEEI.MarketingCompanywasincludedinthe divestitureofNewAERtoIPHinDecember2013.Following theNewAERdivestiture,MarketingCompanybecame IllinoisPowerMarketingCompany.

MATS-MercuryandAirToxicsStandards,anEPArulethatlimitsemissionofmercuryandotherairtoxicsfromcoal andoil-firedelectricgeneratingunits.

MedinaValley-AmerenEnergyMedinaValleyCogen,LLC,anAmerenCorporationsubsidiary.Thiscompanywas distributedfromAERtoAmereninMarch2013.

MEEIA-MissouriEnergyEfficiencyInvestmentAct,aMissourilawthatallowselectricutilitiestorecovercosts relatedtoMoPSC-approvedcustomerenergyefficiency

programs.

MegawatthourorMWh-Onethousandkilowatthours.MerchantGeneration-Aformerfinancialreportingsegmentthat,priortothedivestitureofNewAERtoIPHin December2013,consistedprimarilyoftheoperationsof AER,includingGenco,AERG,MarketingCompanyand, throughMarch2013,MedinaValley.

MGP-Manufacturedgasplant.

MISO-MidcontinentIndependentSystemOperator,Inc.,anRTO.

MissouriCreditAgreement-Ameren'sandAmerenMissouri's$1billionmultiyearseniorunsecuredcredit agreement.Theagreementwasamendedandrestatedin December2014andiscurrentlyscheduledtoexpireon December11,2019.MissouriEnvironmentalAuthority-EnvironmentalImprovementandEnergyResourcesAuthorityofthestate ofMissouri,agovernmentalbodyauthorizedtofinance environmentalprojectsbyissuingtax-exemptbondsand

notes.

Mmbtu-OnemillionBtus.Moneypool-BorrowingagreementsamongAmerenanditssubsidiariestocoordinateandprovideforcertainshort-termcashandworkingcapitalrequirements.

Moody's-Moody'sInvestorsServiceInc.,acreditrating agency.2 MoPSC-MissouriPublicServiceCommission,astateagencythatregulatesMissouriutilitybusinesses,includingAmerenMissouri.

MTM-Mark-to-market.

MW-Megawatt.Nativeload-End-useretailcustomerswhomweareobligatedtoservebystatute,franchise,contract,orother regulatoryrequirement.

NEIL-NuclearElectricInsuranceLimited,whichincludesallofitsaffiliatedcompanies.

NERC-NorthAmericanElectricReliabilityCorporation.Netenergycosts-Netenergycosts,asdefinedintheFAC,includefuelandpurchasedpowercosts,including transportation,netofoff-systemsales.AsofMay30,2015, transmissionrevenuesandsubstantiallyalltransmission chargesareexcludedfromnetenergycostsasaresultof theApril2015MoPSCelectricrateorder.

Netsharedbenefits-AmerenMissouri'sshareofthepresentvalueoflifetimeenergysavings,netofprogram costs,designedtooffsetsalesvolumereductionsresulting fromAmerenMissouri'scustomerenergyefficiency programs.Thisrecoverymechanismwasapplicabletothe MEEIAplanfor2013through2015.

NewAER-NewAmerenEnergyResourcesCompany,LLC,alimitedliabilitycompanyformedasadirectwhollyowned subsidiaryofAER.NewAER,acquiredbyIPHinDecember 2013,includedsubstantiallyalloftheassetsandliabilities ofAER,exceptforcertainassetsandliabilitiesretainedby Ameren.FollowingtheNewAERdivestiture,NewAER becameIllinoisPowerResources,LLC.

NO x-Nitrogenoxides.

Noranda-NorandaAluminum,Inc.

NPNS-Normalpurchasesandnormalsales.

NRC-NuclearRegulatoryCommission,aUnitedStatesgovernmentagency.

NSPS-NewSourcePerformanceStandards,provisionsundertheCleanAirAct.

NSR-NewSourceReviewprovisionsoftheCleanAirAct,whichincludeNonattainmentNewSourceReviewand PreventionofSignificantDeteriorationregulations.

NWPA-NuclearWastePolicyActof1982,asamended.

NYMEX-NewYorkMercantileExchange.

NYSE-NewYorkStockExchange,Inc.

OATT-OpenAccessTransmissionTariff.

OCI-Othercomprehensiveincome(loss)asdefinedby GAAP.

Off-systemsalesrevenues-Revenuesfromotherthannativeloadsales,includingwholesalesales.

OTC-Over-the-counter.

PGA-PurchasedGasAdjustmenttariffs,whichpermitprudentlyincurrednaturalgascoststoberecovereddirectly fromutilitycustomerswithoutatraditionalrateproceeding.

PUHCA2005-ThePublicUtilityHoldingCompanyActof 2005.QIP-Qualifyinginfrastructureplant.Costsofqualifyinginfrastructurenaturalgasplantthatisincludedinan AmerenIllinoisrecoverymechanism.

Ratebase-Thenetvalueofpropertyonwhichapublicutilityispermittedtoearnanallowedrateofreturn.

Regulatorylag-Theexposuretodifferencesincostsincurredandactualsalesvolumelevelsascomparedwith theassociatedamountsincludedincustomerrates.Rate increaserequestsintraditionalratecaseproceedingscan takeupto11monthstobeacteduponbytheMoPSCand theICC.Asaresult,revenueincreasesauthorizedby regulatorswilllagbehindchangingcostsandsalesvolume levelswhenbasedonhistoricalperiods.

Revenuerequirement-Thecostofprovidingutilityservicetocustomers,whichiscalculatedasthesumofautility's recoverableoperatingandmaintenanceexpenses, depreciationandamortizationexpense,taxes,andan allowedreturnoninvestment.

RFP-Requestforproposal.RocklandCapital-RocklandCapital,LLC,togetherwiththespecialpurposeentityaffiliatedwith,andformedby, RocklandCapital,LLC,thatacquiredtheElgin,GibsonCity, andGrandTowergas-firedenergycentersinJanuary2014.

RTO-Regionaltransmissionorganization.

S&P-Standard&Poor'sRatingsServices,acreditrating agency.

SEC-SecuritiesandExchangeCommission,aUnitedStatesgovernmentagency.

SERC-SERCReliabilityCorporation,oneoftheregionalelectricreliabilitycouncilsorganizedforcoordinatingthe planningandoperationofthenation'sbulkpowersupply.

SO 2-Sulfurdioxide.Testyear-Theselectedperiodoftime,typicallya12-monthperiod,forwhichautility'shistoricalorforecasted operatingresultsareusedtodeterminetheappropriate revenuerequirement.

Throughputdisincentive-AmerenMissouri'sreducedmargincausedbythecurrentperiod'slowersalesvolume resultingfromMEEIAcustomerenergyefficiencyprograms.

RecoveryofthisdisincentiveisdesignedtomakeAmeren Missouriearningsneutraleachperiodfromthelostmargins causedbyitscurrentMEEIAcustomerenergyefficiency programs.Thisrecoverymechanismisapplicabletothe MEEIAplanfromMarch2016throughFebruary2019.

UA-UnitedAssociationofPlumbersandPipefitters,alaborunion.

VBA-AvolumebalancingadjustmentforAmerenIllinois'naturalgasoperations.Asaresultofthisadjustment, revenuesfromresidentialandsmallnonresidential customerswillincreaseordecreaseasbillingdeterminants differfromfiledamounts.Thisadjustmentensuresthat changesinsalesvolumes,includingdeviationsfromnormal weatherconditions,donotresultinanover-orunder-collectionofnaturalgasrevenuesfortheserateclasses.

3 FORWARD-LOOKINGSTATEMENTSStatementsinthisreportnotbasedonhistoricalfactsareconsidered"forward-looking"and,accordingly,involverisksanduncertaintiesthatcouldcauseactualresultsto differmateriallyfromthosediscussed.Althoughsuch forward-lookingstatementshavebeenmadeingoodfaith andarebasedonreasonableassumptions,thereisno assurancethattheexpectedresultswillbeachieved.These statementsinclude(withoutlimitation)statementsasto futureexpectations,beliefs,plans,strategies,objectives, events,conditions,andfinancialperformance.In connectionwiththe"safeharbor"provisionsofthePrivate SecuritiesLitigationReformActof1995,weareproviding thiscautionarystatementtoidentifyimportantfactorsthat couldcauseactualresultstodiffermateriallyfromthose anticipated.Thefollowingfactors,inadditiontothose discussedunderRiskFactors,andelsewhereinthisreport andinourotherfilingswiththeSEC,couldcauseactual resultstodiffermateriallyfrommanagementexpectations suggestedinsuchforward-lookingstatements:

regulatory,judicial,orlegislativeactions,includingchangesinregulatorypoliciesandratemaking determinations,thatmayresultfromthecomplaint casesfiledwiththeFERCseekingareductioninthe allowedbasereturnoncommonequityundertheMISO tariff,AmerenMissouri'sappealofthemethodand inputsusedtocalculateitsperformanceincentive underMEEIAfor2014and2015,andfutureregulatory, judicial,orlegislativeactionsdesignedtochange regulatoryrecoverymechanisms; theeffectofAmerenIllinoisparticipatingina performance-basedformularatemakingprocessunder theIEIMA,includingthedirectrelationshipbetween AmerenIllinois'returnoncommonequityand30-year UnitedStatesTreasurybondyields,therelatedfinancial commitmentsrequiredbytheIEIMA,andtheresulting uncertainimpactonAmerenIllinois'resultsof operations,financialposition,andliquidity; ourabilitytoalignouroverallspending,bothoperating andcapital,withregulatoryframeworksestablishedby ourregulatorsinanattempttoearnourallowedreturn onequity;theeffectsofchangesinlawsandothergovernmental actions,includingmonetary,fiscal,tax,andenergy

policies;theeffectsofchangesinfederal,state,orlocaltax laws,regulations,interpretations,orratesandany challengestothetaxpositionstakenbytheAmeren

Companies; theeffectsondemandforourservicesresultingfrom technologicaladvances,includingadvancesin customerenergyefficiencyanddistributedgeneration sources,whichgenerateelectricityatthesiteof consumptionandarebecomingmorecost-competitive; theeffectivenessofAmerenMissouri'scustomerenergy efficiencyprogramsandtherelatedamountofany revenuesandperformanceincentiveearnedunderthe MEEIAplansapprovedinAugust2012andFebruary2016andunderanyfutureapprovedMEEIAplan; thetimingofincreasingcapitalexpenditureand operatingexpenserequirementsandourabilityto recoverthesecostsinatimelymanner; thecostandavailabilityoffuelsuchascoal,natural gas,andenricheduraniumusedtoproduceelectricity; thecostandavailabilityofpurchasedpowerandnatural gasfordistribution;andthelevelandvolatilityoffuture marketpricesforsuchcommodities,includingour abilitytorecoverthecostsforsuchcommoditiesand ourcustomers'tolerancefortherelatedrateincreases; disruptionsinthedeliveryoffuel,failureofourfuel supplierstoprovideadequatequantitiesorqualityof fuel,orlackofadequateinventoriesoffuel,including ultra-low-sulfurcoalusedforAmerenMissouri's compliancewithenvironmentalregulations; theeffectivenessofourriskmanagementstrategies andouruseoffinancialandderivativeinstruments; theabilitytoobtainsufficientinsurance,including insurancerelatingtoAmerenMissouri'sCallaway energycenterandinsuranceforcyberattacksor,inthe absenceofinsurance,theabilitytorecoveruninsured lossesfromcustomers; businessandeconomicconditions,includingtheir impactonkeycustomers,interestrates,collectionof ourreceivablebalances,anddemandforourproducts; Noranda'sbankruptcyfiling,theexpectedcurtailmentof operationsatitsaluminumsmelterlocatedinsoutheast Missouri,andtheresultingimpactstoAmeren Missouri'sabilitytorecoveritsrevenuerequirement; revisionstoAmerenMissouri'slong-termpowersupply agreementwithNoranda,includingAmerenMissouri's notificationtoterminatetheagreementeffectiveJune1, 2020,andAmerenMissouri'sdecisionastowhetherto seekMoPSCapprovaltoceaseprovidingelectricityto Norandathereafter; disruptionsofthecapitalmarkets,deteriorationincredit metricsoftheAmerenCompanies,orothereventsthat mayhaveanadverseeffectonthecostoravailabilityof capital,includingshort-termcreditandliquidity; theimpactoftheadoptionofnewaccountingguidance andtheapplicationofappropriatetechnicalaccounting rulesandguidance; actionsofcreditratingagenciesandtheeffectsofsuch

actions;theimpactofweatherconditionsandothernatural phenomenaonusandourcustomers,includingthe impactofsystemoutages; theconstruction,installation,performance,andcost recoveryofgeneration,transmission,anddistribution

assets;theeffectsofbreakdownsorfailuresofequipmentin theoperationofnaturalgasdistributionand transmissionsystemsandstoragefacilities,suchas leaks,explosionsandmechanicalproblems,and compliancewithnaturalgassafetyregulations; theeffectsofourincreasinginvestmentinelectric transmissionprojectsandtheuncertaintyastowhether wewillachieveourexpectedreturnsinatimelyfashion; 4

operationofAmerenMissouri'sCallawayenergycenter,includingplannedandunplannedoutages,and decommissioningcosts; theeffectsofstrategicinitiatives,includingmergers, acquisitions,anddivestitures,andanyrelatedtax

implications; theimpactofcurrentenvironmentalregulationsand new,morestringent,orchangingrequirements, includingthoserelatedtoCO 2,otheremissionsanddischarges,coolingwaterintakestructures,CCR,and energyefficiency,thatareenactedovertimeandthat couldlimitorterminatetheoperationofcertainofour energycenters,increaseourcostsorinvestment requirements,resultinanimpairmentofourassets, causeustosellourassets,reduceourcustomers' demandforelectricityornaturalgas,orotherwisehave anegativefinancialeffect; theimpactofcomplyingwithrenewableenergy portfoliorequirementsinMissouri; labordisputes,workforcereductions,futurewageand employeebenefitscosts,includingchangesindiscount rates,mortalitytables,andreturnsonbenefitplan

assets;theinabilityofourcounterpartiestomeettheir obligationswithrespecttocontracts,credit agreements,andfinancialinstruments; thecostandavailabilityoftransmissioncapacityforthe energygeneratedbyAmerenMissouri'senergycenters orrequiredtosatisfyAmerenMissouri'senergysales; legalandadministrativeproceedings; theimpactofcyberattacks,whichcouldresultinthe lossofoperationalcontrolofenergycentersand electricandnaturalgastransmissionanddistribution systemsand/orthelossofdata,suchasutility customerdataandaccountinformation;and actsofsabotage,war,terrorism,orotherintentionally disruptiveacts.Newfactorsemergefromtimetotime;itisnotpossibleformanagementtopredictallsuchfactors,norcanitassesstheimpactofeachsuchfactoronthebusinessortheextenttowhichanyfactor,orcombinationoffactors,maycauseactual resultstodiffermateriallyfromthosecontainedorimpliedinanyforward-lookingstatement.Giventheseuncertainties,undue relianceshouldnotbeplacedontheseforward-lookingstatements.Excepttotheextentrequiredbythefederalsecuritieslaws, weundertakenoobligationtoupdateorrevisepubliclyanyforward-lookingstatementstoreflectnewinformationorfuture

events.PARTIITEM1.BUSINESS GENERALAmeren,headquarteredinSt.Louis,Missouri,isapublicutilityholdingcompanyunderPUHCA2005.Amerenwasformedin1997bythemergerofAmerenMissouriand CIPSCOInc.,whichwastheparentcompanyofCIPS.

AmerenacquiredCILCORPInc.,whichwastheparent companyofCILCO,in2003andIPin2004.CIPS,CILCO, andIPweremergedtoformAmerenIllinoisin2010.

Ameren'sprimaryassetsareitsequityinterestsinits subsidiaries,includingAmerenMissouriandAmeren Illinois.Ameren'ssubsidiariesareseparate,independent legalentitieswithseparatebusinesses,assets,and liabilities.DividendsonAmeren'scommonstockandthe paymentofexpensesbyAmerendependondistributions madetoitbyitssubsidiaries.BelowisasummarydescriptionofAmerenMissouriandAmerenIllinois.Amoredetaileddescriptioncanbe foundinNote1-SummaryofSignificantAccounting PoliciesunderPartII,Item8,ofthisreport.

AmerenMissourioperatesarate-regulatedelectricgeneration,transmission,anddistributionbusinessand arate-regulatednaturalgastransmissionand distributionbusinessinMissouri.

AmerenIllinoisoperatesrate-regulatedelectricand naturalgastransmissionanddistributionbusinessesin

Illinois.Amerenhasvariousothersubsidiariesthatconductactivitiessuchastheprovisionofsharedservices.Ameren alsohasasubsidiary,ATXI,thatoperatesaFERCrate-regulatedelectrictransmissionbusiness.ATXIisdeveloping MISO-approvedelectrictransmissionprojects,includingthe IllinoisRivers,SpoonRiver,andMarkTwainprojects.

Amerenisalsopursuingprojectstoimproveelectric transmissionsystemreliabilitywithinAmerenMissouri's andAmerenIllinois'serviceterritoriesaswellas competitiveelectrictransmissioninvestmentopportunities outsideoftheseterritories,includinginvestmentsoutsideof

MISO.InDecember2013,AmerencompletedthedivestitureofNewAERtoIPH.InJanuary2014,MedinaValley completeditssaleoftheElgin,GibsonCity,andGrand Towergas-firedenergycenterstoRocklandCapital.In addition,in2013,AmerenabandonedtheMeredosiaand Hutsonvilleenergycentersuponthecompletionofthe divestitureofNewAERtoIPH.Amerenisdemolishingthe Hutsonvilleenergycenterandexpectstodemolishthe Meredosiaenergycenterbeginningin2016.Asaresultof theseevents,Amerenhassegregatedtheoperatingresults, assets,andliabilitiesforNewAERandfortheElgin,Gibson City,GrandTower,Meredosia,andHutsonvilleenergy centersandpresentedthemseparatelyasdiscontinued operationsforallperiodspresentedinthisreport.Unless 5

otherwisestated,thefollowinginformationpresentedinPartI,Item1,ofthisreportexcludesdiscontinued operationsforallperiodspresented.SeeNote16-DivestitureTransactionsandDiscontinuedOperationsunder PartII,Item8,ofthisreportforadditionalinformation.ThefollowingtablepresentsourtotalemployeesatDecember31,2015:AmerenMissouri

.................................

3,773AmerenIllinois

...................................

3,305AmerenServices

.................................

1,449 Ameren........................................

8,527AtDecember31,2015,theIBEW,theIUOE,theLIUNA,andtheUAlaborunionscollectivelyrepresented about54%ofAmeren'stotalemployees.Theyrepresented 63%and59%oftheemployeesatAmerenMissouriand AmerenIllinois,respectively.Thecollectivebargaining agreementshavetermsrangingfromtwotosixyearsand expirebetween2016and2018.Foradditionalinformationaboutthedevelopmentofourbusinesses,ourbusinessoperations,andfactors affectingouroperationsandfinancialposition,see Management'sDiscussionandAnalysisofFinancial ConditionandResultsofOperationsunderPartII,Item7, ofthisreportandNote1-SummaryofSignificant AccountingPoliciesunderPartII,Item8,ofthisreport.BUSINESSSEGMENTSAmerenhastworeportablesegments:AmerenMissouriandAmerenIllinois.AmerenMissouriandAmerenIllinoiseachhaveonereportablesegment.TheAmeren MissourisegmentforbothAmerenandAmerenMissouri includesalltheoperationsofAmerenMissouri.TheAmeren IllinoissegmentforbothAmerenandAmerenIllinois consistsofalloftheoperationsofAmerenIllinois.See Note1-SummaryofSignificantAccountingPoliciesand Note17-SegmentInformationunderPartII,Item8,ofthis reportforadditionalinformationonreportingsegments.RATESANDREGULATION RatesTheratesthatAmerenMissouri,AmerenIllinois,andATXIareallowedtochargefortheirutilityservicessignificantlyinfluencetheresultsofoperations,financial position,andliquidityofthesecompaniesandAmeren.The electricandnaturalgasutilityindustryishighlyregulated.

Theutilityrateschargedtocustomersaredeterminedby governmentalentities,includingtheMoPSC,theICC,and theFERC.Decisionsbytheseentitiesareinfluencedby manyfactors,includingthecostofprovidingservice,the prudencyofexpenditures,thequalityofservice,regulatory staffknowledgeandexperience,customerintervention,and economicconditions,aswellassocialandpoliticalviews.

Decisionsmadebythesegovernmentalentitiesregarding ratesarelargelyoutsideofourcontrol.Thesedecisions,as wellastheregulatorylaginvolvedinfilingandgettingnew ratesapproved,couldhaveamaterialadverseeffectonthe resultsofoperations,financialposition,andliquidityofthe AmerenCompanies.Theextentoftheregulatorylagvaries foreachofAmeren'selectricandnaturalgasjurisdictions, withtheFERC-regulatedelectrictransmissionandIllinois electricdistributionjurisdictionsexperiencingtheleast amountofregulatorylag.Dependingonthejurisdiction,the effectsofregulatorylagaremitigatedthroughavarietyof means,includingtheuseofafuturetestyear,the implementationoftrackersandriders,thelevelandtiming ofexpenditures,andbyregulatoryframeworksthatinclude annualrevenuerequirementreconciliations.TheMoPSCregulatesratesandothermattersforAmerenMissouri.TheICCregulatesratesandothermatters forAmerenIllinois,aswellasnon-rateutilitymattersfor ATXI.ATXIdoesnothaveretaildistributioncustomers; therefore,theICCdoesnothaveauthoritytoregulateits rates.TheFERCregulatesAmerenMissouri's,Ameren Illinois',andATXI'scost-basedratesforthewholesale distributionandtransmissionofenergyininterstate commerceandvariousothermattersdiscussedbelow underGeneralRegulatoryMatters.Thefollowingtablesummarizes,byratejurisdiction,thekeytermsoftherateordersineffectforcustomerbillingsforeachofAmeren'srate-regulatedutilitiesasofJanuary1,2016:

Regulator Allowed Return on Equity Percent of Common EquityRateBase(inbillions)PortionofAmeren's2015 Operating Revenues (a)AmerenMissouriElectricservice (b)(c)........................................MoPSC9.53%51.8%$7.056%Naturalgasdeliveryservice (d)...............................MoPSC(d)52.9%$0.22%AmerenIllinoisElectricdistributiondeliveryservice (e).........................ICC9.14%50.0%$2.525%Naturalgasdeliveryservice (f)................................ICC9.60%50.0%$1.213%Electrictransmissiondeliveryservice (g)........................FERC12.38%51.9%$1.23%

ATXIElectrictransmissiondeliveryservice (g)........................FERC12.38%56.1%$0.91%(a)Includespass-throughcostsrecoveredfromcustomers,suchaspurchasedpowerforelectricdistributiondeliveryserviceandgaspurchasedforresalefornaturalgasdeliveryservice,andintercompanyeliminations.(b)AmerenMissouri'selectricgeneration,transmission,anddeliveryserviceratesarebundledtogetherandchargedtoretailcustomersunderacombinedelectricservicerate.

6 (c)BasedontheMoPSC'sApril2015rateorder.(d)BasedontheMoPSC'sJanuary2011rateorder.Thisrateorderdidnotspecifytheallowedreturnonequity.ItincludestheimpactsonratebaseandoperatingrevenuesrelatingtotheISRSforinvestmentsaftertheJanuary2011rateorder.(e)BasedontheICC'sDecember2015rateorder.AmerenIllinoiselectricdistributiondeliveryserviceratesareupdatedannuallyandbecomeeffectiveeachJanuary.TheDecember2015rateorderwasbasedon2014recoverablecosts,expectednetplantadditionsfor2015,andthe monthlyyieldsduring2014ofthe30-yearUnitedStatesTreasurybondsplus580basispoints.AmerenIllinois'2016electricdistribution deliveryservicerevenueswillbebasedonits2016actualrecoverablecosts,ratebase,andreturnoncommonequity,ascalculatedunderthe IEIMA'sperformance-basedformularatemakingframework.(f)BasedontheICC'sDecember2015rateorder.Therateorderwasbasedona2016futuretestyearandestablishedtheVBA.

(g)TransmissionratesareupdatedannuallyandbecomeeffectiveeachJanuary.Theyaredeterminedbyacompany-specific,forward-lookingrateformulabasedoneachyear'sforecastedinformation.The12.38%returnisthesubjectoftwoFERCcomplaintproceedingsthatarechallenging theallowedreturnoncommonequityforMISOtransmissionownersandwouldrequirecustomerrefundstobeissued.AmerenMissouri ElectricAmerenMissouri'selectricoperatingrevenuesaresubjecttoregulationbytheMoPSC.Ifcertaincriteriaaremet,AmerenMissouri'selectricratesmaybeadjusted withoutatraditionalrateproceeding.Forexample,allof AmerenMissouri'sMEEIAcustomerenergyefficiency programcosts,netsharedbenefitsorthroughput disincentive,andanyperformanceincentive,are recoverablethroughariderthatmaybeadjustedwithouta traditionalrateproceeding.Likewise,theFACpermits AmerenMissouritorecoverorrefund,throughcustomer rates,95%ofchangesinnetenergycostsgreaterthanor lessthantheamountsetinbaserateswithoutatraditional rateproceeding,subjecttoMoPSCprudencereviews.Net energycosts,asdefinedintheFAC,includefueland purchasedpowercosts,includingtransportation,netofoff-systemsales.AsofMay30,2015,transmissionrevenues andsubstantiallyalltransmissionchargesareexcluded fromnetenergycostsasaresultoftheApril2015MoPSC electricrateorder.Undercertainconditions,aprovisionof theFACallowsAmerenMissouritoretainaportionofthe revenuesfromanyoff-systemsalesitmakesasaresultof reducedsalestoNoranda.InadditiontotheFACandtheMEEIArecoverymechanisms,AmerenMissouriemploysothercost recoverymechanisms,includingapensionand postretirementbenefitcosttracker,anuncertaintax positiontracker,arenewableenergystandardscosttracker, andasolarrebateprogramtracker.Eachofthesetrackers allowsAmerenMissouritorecordthedifferencebetween thelevelofincurredcostsunderGAAPandthelevelofsuch costsincludedinratesasaregulatoryassetorregulatory liability,whichwillbeincludedinbaseratesinafuture MoPSCrateorder.AmerenMissouriisamemberofMISO,anditstransmissionrateiscalculatedinaccordancewiththeMISO OATT.TheFERCregulatestherateschargedandtheterms andconditionsforelectrictransmissiondeliveryservice.

ThetransmissionrateisupdatedeachJunebasedon AmerenMissouri'sfilingswiththeFERC.Thisrateisnot directlychargedtoMissouriretailcustomersbecause,in Missouri,theMoPSCincludestransmission-relatedcosts andrevenuesinbundledretailrates.NaturalGasAmerenMissouri'snaturalgasoperatingrevenuesaresubjecttoregulationbytheMoPSC.Ifcertaincriteriaare met,AmerenMissouri'snaturalgasratesmaybeadjusted withoutatraditionalrateproceeding.PGAclausespermit prudentlyincurrednaturalgassupplycoststobepassed directlytocustomers.TheISRSalsopermitscertain prudentlyincurrednaturalgasinfrastructurereplacement coststoberecoveredfromcustomersonamoretimely basisbetweenratecases.Thereturnonequitycurrently usedbyAmerenMissouriforpurposesoftheISRStariffis

10%.AmerenIllinois ElectricAmerenIllinois'electricdistributiondeliveryserviceoperatingrevenuesareregulatedbytheICC,whileitselectrictransmissiondeliveryserviceoperatingrevenues areregulatedbytheFERC.In2015,AmerenIllinois'electric distributiondeliveryserviceaccountedfor91%ofitstotal electricoperatingrevenues.Theremainderrelatedto electrictransmissiondeliveryservice.AmerenIllinoisparticipatesintheperformance-basedformularatemakingprocessestablishedpursuanttothe IEIMA.TheIEIMAwasdesignedtoprovidefortherecovery ofactualcostsofelectricdeliveryservicethatareprudently incurredandtoreflecttheutility'sactualregulatedcapital structurethroughaformulaforcalculatingthereturnon equitycomponentofthecostofcapital.Thereturnon equitycomponentoftheformularateisequaltothe averageforthecalendaryearofthemonthlyyieldsofthe 30-yearUnitedStatesTreasurybondsplus580basis points.AmerenIllinois'actualreturnonequityrelatingto electricdeliveryserviceissubjecttoacollaradjustmenton earningsinexcessof50basispointsgreaterorlessthanits allowedreturn.TheIEIMAprovidesforanannual reconciliationoftherevenuerequirementnecessaryto reflecttheactualcostsincurredinagivenyearwiththe revenuerequirementincludedincustomerratesforthat year,includinganallowedreturnonequity.Thisannual revenuerequirementreconciliationadjustment,alongwith thecollaradjustment,ifnecessary,willbecollectedfromor refundedtocustomerswithinthenexttwoyears.

7 AmerenIllinoisisalsosubjecttoperformancestandardsundertheIEIMA.Failuretoachievethestandardswouldresultinareductioninthecompany'sallowedreturnon equitycalculatedundertheformula.Theperformance standardsincludeimprovementsinservicereliabilityto reduceboththefrequencyanddurationofoutages,reduction inthenumberofestimatedbills,reductionofconsumption oninactivemeters,andareductioninuncollectibleaccounts expense.TheIEIMAprovidesforreturnonequitypenalties totalingupto34basispointsin2016through2018and 38basispointsin2019through2022iftheperformance standardsarenotmet.Thecurrentformularatemaking processiseffectiveuntiltheendof2019,withafurther extensionpossiblethrough2022.UndertheIEIMA,AmerenIllinoisisalsosubjecttocapitalspendinglevels.Between2012and2021,Ameren Illinoisisrequiredtoinvest$625millionincrementaltoits averageelectricdeliveryservicecapitalprojectinvestments of$228millionforcalendaryears2008through2010,on capitalprojectstomodernizeitsdistributionsystem.

Through2015,AmerenIllinoishasinvested$277millionin IEIMAcapitalprojectstowardits$625millionrequirement.

AsrequiredbytheIEIMA,AmerenIllinoismetthejob creationrequirementsduringthepeakprogramyear.AmerenIllinoisemployscostrecoverymechanismsforpowerprocurement,customerenergyefficiencyprograms, certainenvironmentalcosts,andbaddebtexpensenot recoveredinbaserates.AmerenIllinoisalsohasatariff ridertorecoverthecostsofcertainasbestos-relatedclaims.AmerenIllinoisisamemberofMISOanditstransmissionrateiscalculatedinaccordancewiththeMISO OATT.Currently,theFERC-allowedreturnoncommon equityintheratemakingformulaforMISOtransmission ownersis12.38%.However,the12.38%returnissubject toaNovember2013complaintcaseandaFebruary2015 complaintcasethatchallengetheallowedreturnon commonequityforMISOtransmissionowners.In December2015,anadministrativelawjudgeissuedan initialdecisionintheNovember2013complaintcasethat wouldlowertheallowedbasereturnoncommonequityto 10.32%andwouldrequirecustomerrefundstobeissued forthe15-monthperiodendinginFebruary2015.Ameren IllinoishasreceivedFERCapprovaltouseacompany-specific,forward-lookingrateformulaframeworkinsetting itstransmissionrates.Theseforward-lookingratesare updatedeachJanuarywithforecastedinformation.A reconciliationduringtheyear,whichadjustsfortheactual revenuerequirementandactualsalesvolumes,isusedto adjustbillingratesinasubsequentyear.InIllinois,the AMILpricingzonetransmissionrateischargeddirectlyto wholesalecustomersandtoalternativeretailelectric suppliers,whichserveunbundledretailload.TheAMIL pricingzonetransmissionrateandotherMISO-related costsarecollectedthrougharidermechanisminAmeren Illinois'retaildistributiontariffsfromretailcustomerswho havenotchosenanalternativeretailelectricsupplier.NaturalGasAmerenIllinois'naturalgasoperatingrevenuesaresubjecttoregulationbytheICC.InDecember2015,theICC issuedarateorderthatapprovedanincreaseinrevenues forAmerenIllinois'naturalgasdeliveryservicethatwas basedona2016futuretestyear.Inaddition,therateorder approvedtheVBAforresidentialandsmallnonresidential customers.Ifcertaincriteriaaremet,thenAmerenIllinois' naturalgasratesmaybeadjustedwithoutatraditionalrate proceeding.PGAclausespermitprudentlyincurrednatural gascoststobepasseddirectlytocustomers.Also,Ameren Illinoisemployscostrecoverymechanismsforcustomer energyefficiencyprograms,certainenvironmentalcosts, andbaddebtexpensesnotrecoveredinbaserates.InJuly2013,astatelawwasenacted,whichencouragesIllinoisnaturalgasutilitiestoaccelerate modernizationofthestate'snaturalgasinfrastructure.The lawallowsnaturalgasutilitiestofileforaQIPrider.AQIP riderallowsasurchargetobeaddedtocustomers'billsto recoverdepreciationexpensesandtoearnareturnon qualifyingnaturalgasinvestmentsthatwerenotpreviously includedinbaserates.Recoverybeginstwomonthsafter thenaturalgasinvestmentsareplacedinserviceand continuesuntiltheinvestmentsareincludedinbaseratesin afuturenaturalgasrateorder.AmerenIllinoisreceivedICC approvalforitsQIPriderinJanuary2015andsubsequently beganincludingqualifiedinvestmentsandrecording revenueunderthisregulatoryframework.

ATXIATXIisamemberofMISO,anditstransmissionrateiscalculatedinaccordancewiththeMISOOATT.Accordingly,likeAmerenIllinois,ATXI'stransmissionrateissubjectto theNovember2013andFebruary2015complaintcases thatchallengetheallowedreturnoncommonequityfor MISOtransmissionowners.ATXIhasreceivedFERC approvaltouseacompany-specific,forward-lookingrate formulaframeworkinsettingitstransmissionrates.These forward-lookingratesareupdatedeachJanuarywith forecastedinformation.Areconciliationduringtheyear, whichadjustsfortheactualrevenuerequirementandactual salesvolumes,isusedtoadjustbillingratesina subsequentyear.Additionally,theFERChasapproved transmissionrateincentivesrelatingtothethreeMISO-approvedmulti-valueprojectsdiscussedbelow,whichallow constructionworkinprogresstobeincludedinratebase, therebyimprovingthetimelinessofcashrecovery.ThethreeMISO-approvedmulti-valueprojectsbeingdevelopedbyATXIaretheIllinoisRivers,SpoonRiver,and MarkTwainprojects.Thefirstproject,IllinoisRivers, involvestheconstructionofa345-kilovoltlinefromwestern IndianaacrossthestateofIllinoistoeasternMissouri.ATXI hasobtainedacertificateofpublicconvenienceand necessityandprojectapprovalfromtheICCandtheMoPSC foreachstate'sportionoftheIllinoisRiversproject.The lastsectionofthisprojectisexpectedtobecompletedin 8

2019.TheSpoonRiverprojectislocatedinnorthwestIllinois,andtheMarkTwainprojectislocatedinnortheast Missouri;eachoftheseprojectsinvolvestheconstruction of345-kilovoltlinesandonenewsubstation.InSeptember 2015,theICCgrantedATXIacertificateofpublic convenienceandnecessityandprojectapprovalforthe SpoonRiverproject.InJune2015,ATXImadeafilingwith theMoPSCrequestingacertificateofpublicconvenience andnecessityfortheMarkTwainproject.Adecisionis expectedfromtheMoPSCin2016.Thesetwoprojectsare expectedtobecompletedin2018.Thetotalinvestmentby ATXIinallthreeprojectsisexpectedtobemorethan

$1.6billion.ForadditionalinformationonAmerenMissouri,AmerenIllinois,andATXIratematters,includingthe MoPSC'sFebruary2016MEEIAorder,Noranda'susage reductionandbankruptcyfiling,andtheFERCcomplaint caseschallengingtheallowedreturnoncommonequityfor MISOtransmissionowners,seeResultsofOperationsand OutlookinManagement'sDiscussionandAnalysisof FinancialConditionandResultsofOperationsunderPartII, Item7,QuantitativeandQualitativeDisclosuresAbout MarketRiskunderPartII,Item7A,andNote2-Rateand RegulatoryMattersunderPartII,Item8,ofthisreport.GeneralRegulatoryMattersAmerenMissouri,AmerenIllinois,andATXImustreceiveFERCapprovaltoenterintovarioustransactions,suchasissuingshort-termdebtsecuritiesandconducting certainacquisitions,mergers,andconsolidationsinvolving electricutilityholdingcompanies.Inaddition,Ameren Missouri,AmerenIllinois,andATXImustreceive authorizationfromtheapplicablestatepublicutility regulatoryagencytoissuestockandlong-termdebt securities(withmaturitiesofmorethan12months)andto conductmergers,affiliatetransactions,andvariousother

activities.AmerenMissouri,AmerenIllinois,andATXIarealsosubjecttomandatoryreliabilitystandards,including cybersecuritystandardsadoptedbytheFERC,toensurethe reliabilityofthebulkpowerelectricsystem.These standardsaredevelopedandenforcedbyNERCpursuantto authoritydelegatedtoitbytheFERC.IfAmerenMissouri, AmerenIllinois,orATXIaredeterminednottobein compliancewithanyofthesemandatoryreliability standards,theycouldincursubstantialmonetarypenalties andothersanctions.UnderPUHCA2005,theFERCandanystatepublicutilityregulatoryagencymayaccessbooksandrecordsof Amerenanditssubsidiariesthataredeterminedtobe relevanttocostsincurredbyAmeren'srate-regulated subsidiariesthatmayaffectjurisdictionalrates.PUHCA 2005alsopermitstheMoPSCandtheICCtorequestthat theFERCreviewcostallocationsbyAmerenServicesto otherAmerencompanies.OperationofAmerenMissouri'sCallawayenergycenterissubjecttoregulationbytheNRC.InMarch2015,theNRCextendedtheCallawayenergycenter'soperating licensefrom2024to2044.AmerenMissouri'sOsage hydroelectricenergycenterandTaumSaukpumped-storagehydroelectricenergycenter,aslicensedprojects undertheFederalPowerAct,aresubjecttoFERC regulationsaffecting,amongotheraspects,thegeneral operationandmaintenanceoftheprojects.Thelicensefor theOsagehydroelectricenergycenterexpiresin2047.The licensefortheTaumSaukpumped-storagehydroelectric energycenterexpiresin2044.AmerenMissouri'sKeokuk energycenteranditsdamintheMississippiRiverbetween Hamilton,Illinois,andKeokuk,Iowa,areoperatedunder authoritygrantedbyanActofCongressin1905.Foradditionalinformationonregulatorymatters,seeNote2-RateandRegulatoryMatters,Note10-Callaway EnergyCenter,andNote15-Commitmentsand ContingenciesunderPartII,Item8,ofthisreport.EnvironmentalMattersCertainofouroperationsaresubjecttofederal,state,andlocalenvironmentalstatutesandregulationsrelatingtothesafetyandhealthofpersonnel,thepublic,andthe environment.Theseenvironmentalstatutesandregulations includerequirementsrelatingtoidentification,generation, storage,handling,transportation,disposal,recordkeeping, labeling,reporting,andemergencyresponseinconnection withhazardousandtoxicmaterials;safetyandhealth standards;andenvironmentalprotectionrequirements, includingstandardsandlimitationsrelatingtothedischarge ofairandwaterpollutantsandthemanagementofwaste andbyproductmaterials.Failuretocomplywiththese statutesorregulationscouldhavematerialadverseeffects onus.Wecouldbesubjecttocriminalorcivilpenaltiesby regulatoryagenciesorwecouldbeorderedbythecourtsto payprivateparties.Exceptasindicatedinthisreport,we believethatweareinmaterialcompliancewithexisting statutesandregulationsthatcurrentlyapplytoour

operations.TheEPAhaspromulgatedseveralenvironmentalregulationsthatwillhaveasignificantimpactontheelectric utilityindustry.Overtime,compliancewiththeseregulations couldbecostlyforcertaincompanies,includingAmeren Missouri,thatoperatecoal-firedpowerplants.Significant newrulesincludetheregulationofCO 2emissionsfromexistingpowerplantsthroughtheCleanPowerPlanandfrom newpowerplantsthroughtherevisedNSPS;theCSAPR, whichrequiresfurtherreductionsofSO 2emissionsandNO xemissionsfrompowerplants;aregulationgoverning managementandstorageofCCR;theMATS,whichrequire reductionofemissionsofmercury,toxicmetals,andacid gasesfrompowerplants;revisedNSPSforparticulate matter,SO 2,andNO xemissionsfromnewsources;neweffluentstandardsapplicabletowastewaterdischargesfrom powerplantsandnewregulationsundertheCleanWaterAct thatcouldrequiresignificantcapitalexpenditures,suchas modificationstowaterintakestructuresornewcooling towersatAmerenMissouri'senergycenters.TheEPAalso periodicallyreviewsandrevisesnationalambientairquality 9

standards,includingthosestandardsassociatedwithemissionsfrompowerplants,suchasparticulatematter, ozone,SO 2andNO x.Certainofthesenewregulationsarebeingorarelikelytobechallengedthroughlitigation,sotheir ultimateimplementation,aswellasthetimingofanysuch implementation,isuncertain.Althoughmanydetailsoffuture regulationsareunknown,individuallyorthecombinedeffects ofnewenvironmentalregulationscouldresultinsignificant capitalexpendituresandincreasedoperatingcostsfor AmerenandAmerenMissouri.Compliancewithallofthese environmentallawsandregulationscouldbeprohibitively expensive,resultintheclosureoralterationoftheoperation ofsomeofAmerenMissouri'senergycenters,orrequire capitalinvestment.AmerenandAmerenMissouriexpectthat thesecostswouldberecoverablethroughrates,subjectto MoPSCprudencereview,butthenatureandtimingofcosts couldresultinregulatorylag.Thesenewandproposed environmentalregulationscouldalsoimpacttheavailability, costof,anddemandforpowerandnaturalgas,whichis acquiredforAmerenMissouri'snaturalgascustomersand AmerenIllinois'electricandnaturalgascustomers.Foradditionaldiscussionofenvironmentalmatters,includingNOx,SO 2,andmercuryemissionreductionrequirements,reductionstoCO 2emissions,wastewaterdischargestandards,remediationefforts,CCRmanagement regulations,andadiscussionoftheEPA'sallegationsof violationsoftheCleanAirActandMissourilawin connectionwithprojectsatAmerenMissouri'sRushIsland energycenter,seeNote15-Commitmentsand ContingenciesunderPartII,Item8,ofthisreport.TRANSMISSIONANDSUPPLYOFELECTRICPOWERAmerenownsanintegratedtransmissionsystemthatiscomprisedofthetransmissionassetsofAmerenMissouri,AmerenIllinois,andATXI.Amerenalsooperates twobalancingauthorityareas:AMMOandAMIL.During 2015,thepeakdemandwas8,071megawattsinAMMO and8,642megawattsinAMIL.TheAmerentransmission systemdirectlyconnectswith15otherbalancingauthority areasfortheexchangeofelectricenergy.AmerenMissouri,AmerenIllinois,andATXIaretransmission-owningmembersofMISO.AmerenMissouri isauthorizedbytheMoPSCtoparticipateinMISOthrough May2018.AmerenMissouriisrequiredtofileastudywith theMoPSCinNovember2017,asithasdoneperiodically sinceitbeganparticipatinginMISO,thatevaluatesthe costsandbenefitsofAmerenMissouri'scontinued participationinMISObeyondMay2018.TheAmerenCompaniesaremembersoftheSERC.TheSERCisresponsibleforthebulkelectricpowersystem inallorportionsof16centralandsoutheasternstates.

Ownersandoperators,includingtheAmerenCompanies,of thebulkelectricpowersystemaresubjecttomandatory reliabilitystandardspromulgatedbytheNERCandits regionalentities,suchastheSERC,whichareallenforced bytheFERC.AmerenMissouriAmerenMissouri'selectricsupplyisprimarilygeneratedfromitsenergycenters.Factorsthatcouldcause AmerenMissouritopurchasepowerinclude,amongother things,absenceofsufficientownedgeneration,energy centeroutages,thefulfillmentofrenewableenergyportfolio requirements,thefailureofsupplierstomeettheirpower supplyobligations,extremeweatherconditions,andthe availabilityofpoweratacostlowerthanitsgenerationcost.AmerenMissouricontinuestoevaluateitslonger-termneedsfornewgeneratingcapacity.Thepotentialneedfor newenergycenterconstructionisdependentonseveralkey factors,includingcontinuationof,andcustomer participationin,energyefficiencyprograms,loadgrowth, andmorestringentenvironmentalregulationofcoal-fired powerplants,whichcouldleadtotheretirementofcurrent baseloadassetsoralterationsinthemannerinwhichthose assetsoperate.Becauseofthesignificanttimerequiredto plan,acquirepermitsfor,andbuildabaseloadenergy center,AmerenMissouricontinuestostudyalternativesand itistakingstepstopreserveoptionstomeetfuture demand.Stepsincludeevaluatingthepotentialfor additionalcustomerenergyefficiencyprogramsandoptions forrenewableenergygeneration,andpotentialsitesfor natural-gas-firedgenerationtofurtherdiversifyits generationportfolio.During2015,AmerenMissouri discontinueditseffortstolicenseandbuildasecond nuclearunitatitsexistingCallawaysiteandhaswithdrawn itsCOLapplicationwiththeNRC.AmerenMissourifileditsnonbindingintegratedresourceplanwiththeMoPSCinOctober2014,priortothe issuanceoftheCleanPowerPlan.Theintegratedresource planisa20-yearplanthatsupportsamorefuel-diverse energyportfolioinMissouri,includingcoal,solar,wind, hydro,naturalgasandnuclearpower.Theplanincludes expandingrenewablegeneration,retiringcoal-fired generationasenergycentersreachtheendoftheiruseful lives,continuationandexpansionofthethen-existing energyefficiencyprograms,andaddingnatural-gas-fired combinedcyclegeneration.SeealsoOutlookinManagement'sDiscussionandAnalysisofFinancialConditionandResultsofOperations underPartII,Item7,Note2-RateandRegulatoryMatters, Note10-CallawayEnergyCenter,andNote15-CommitmentsandContingenciesunderPartII,Item8,ofthis

report.AmerenIllinoisInIllinois,electrictransmissionanddistributionserviceratesareregulatedbutpowersupplypricesarenot regulated.Althoughelectriccustomersareallowedto purchasepowerfromanalternativeretailelectricsupplier, AmerenIllinoisisrequiredtoserveastheprovideroflast resortforitselectriccustomers.In2015,AmerenIllinois suppliedpowerforapproximately26%ofitskilowatthour sales.PowerpurchasedbyAmerenIllinoisforitsretail 10 customerscomeseitherthroughprocurementprocessesconductedbytheIPAorthroughmarketsoperatedby MISO.TheIPAadministersanRFPprocessthroughwhich AmerenIllinoisprocuresitsexpectedsupplyobligation.The powerandrelatedprocurementcostsincurredbyAmeren Illinoisarepasseddirectlytoitscustomersthroughacost recoverymechanism.AmerenIllinoischargestransmissionanddistributionserviceratestocustomerswhopurchase electricityfromalternativeretailelectricsuppliers.SeeNote14-RelatedPartyTransactionsandNote15-CommitmentsandContingenciesunderPartII, Item8,ofthisreportforadditionalinformationonpower procurementinIllinois.POWERGENERATIONThefollowingtablepresentsthesourceofAmeren'sandAmerenMissouri'selectricgeneration,excludingpurchasedpower,fortheyearsendedDecember31,2015,2014,and2013:

CoalNuclearNaturalGas/OilRenewables (a)2015...............................................71%25%(b)4%

2014...............................................7621(b)3 2013...............................................7720(b)3(a)RenewablepowergenerationincludesproductionfromAmerenMissouri'shydroelectric,methanegas,andsolarenergycenters,butitexcludespurchasedrenewableenergycredits.(b)Lessthan1%oftotalfuelsupply.ThefollowingtablepresentsthecostoffuelsforelectricgenerationfortheyearsendedDecember31,2015,2014,and 2013:CostofFuels(dollarspermmbtu)201520142013 Coal (a).......................................................................$2.193$2.151$2.050 Nuclear (b)....................................................................

0.9280.9180.942Naturalgas (c)..................................................................

7.42211.2267.907Weightedaverage-allfuels (d)....................................................$1.910$1.936$1.874(a)Thecostofcoalandthecostsfortransportation,whichincludehedgesforrailroaddieselfuelsurcharges.(b)Thecostofuraniumanditsprocessingtobecomenuclearfuel.

(c)Thecostofnaturalgasandfixedandvariablecostsfortransportation,storage,balancing,andfuellossesfordeliverytotheenergycenter.

(d)Allcosts,includingtransportation,forfuelsusedinourenergycenters,includingcoal,nuclear,naturalgas,methanegas,andoil.Methanegasandoilarenotindividuallylistedinthistablebecausetheiruseisminimal.

CoalAmerenMissourihasanongoingneedforcoalforgeneration,soitpursuesaprice-hedgingstrategyconsistentwiththisrequirement.AmerenMissourihas agreementsinplacetopurchasecoalandtotransportitto energycenters.MostofAmerenMissouri'scoalsupply agreementsexpireattheendof2017,anditsexistingcoal transportagreementsexpireattheendof2019.Ameren Missourihasadditionalcoalsupplycontractsinplaceto provideaportionofitscoalsupplyin2018.Ameren MissourihascoaltransportagreementswithUnionPacific RailroadandBurlingtonNorthernSantaFeRailway.Asof December31,2015,AmerenMissourihadprice-hedged 100%ofitsexpectedcoalsupplyandcoaltransportation requirementsforgenerationin2016.AmerenMissouri burned18milliontonsofcoalin2015.About98%ofAmerenMissouri'scoalispurchasedfromthePowderRiverBasininWyoming.Theremaining coalistypicallypurchasedfromtheIllinoisBasin.Inventory maybeadjustedbecauseofgenerationlevelsor uncertaintiesofsupplyduetopotentialworkstoppages, delaysincoaldeliveries,equipmentbreakdowns,andother factors.DeliveriesfromthePowderRiverBasinhaveoccasionallybeenrestrictedbecauseofrailcongestionand maintenance,derailments,andweather.Asof December31,2015,coalinventoriesforAmerenMissouri wereneartargetedlevels.Disruptionsincoaldeliveries couldcauseAmerenMissouritopursueastrategythat couldincludereducingsalesofpowerduringlow-margin periods,buyinghigher-costfuelstogeneraterequired electricity,andpurchasingpowerfromothersources.

NuclearTheproductionofnuclearfuelinvolvestheminingandmillingofuraniumoretoproduceuraniumconcentrates,theconversionofuraniumconcentratestouraniumhexafluoride gas,theenrichmentofthatgas,theconversionofthe enricheduraniumhexafluoridegasintouraniumdioxidefuel pellets,andthefabricationintousablefuelassemblies.

AmerenMissourihasenteredintouranium,uranium conversion,uraniumenrichment,andfabricationcontractsto procurethefuelsupplyforitsCallawaynuclearenergycenter.TheCallawayenergycenterrequiresrefuelingat18-monthintervals.Thelastrefuelingwascompletedin November2014.Thenextrefuelingsarescheduledforthe springof2016andthefallof2017.AsofDecember31, 11 2015,AmerenMissourihasagreementsorinventoriestoprice-hedge100%ofCallaway's2016springrefueling requirements.AmerenMissourihasuranium(concentrate andhexafluoride)inventoriesandsupplycontracts sufficienttomeetallofitsuraniumandconversion requirementsatleastthrough2018.AmerenMissourihas enricheduraniuminventoriesandenrichmentsupply contractssufficienttosatisfyenrichmentrequirements throughatleast2020andfuelfabricationservicecontracts throughatleast2022.NaturalGasSupplyforGenerationTomaintaindeliveriestonatural-gas-firedenergycentersthroughouttheyear,especiallyduringthesummerpeakdemand,AmerenMissouri'sportfolioofnaturalgas supplyresourcesincludesfirmtransportationcapacityand firmno-noticestoragecapacityleasedfrominterstate pipelines.AmerenMissouriprimarilyusestheinterstate pipelinesystemsofPanhandleEasternPipeLineCompany, TrunklineGasCompany,NaturalGasPipelineCompanyof America,andMississippiRiverTransmissionCorporationto transportnaturalgastoenergycenters.Inadditionto physicaltransactions,AmerenMissouriusesfinancial instruments,includingsomeintheNYMEXfuturesmarket andsomeintheOTCfinancialmarkets,tohedgetheprice paidfornaturalgas.AmerenMissouri'snaturalgasprocurementstrategyisdesignedtoensurereliableandimmediatedeliveryof naturalgastoitsenergycenters.Thisstrategyis accomplishedbyoptimizingtransportationandstorage optionsandbyminimizingcostandpriceriskthrough varioussupplyandprice-hedgingagreementsthatallow accesstomultiplegaspools,supplybasins,andstorage services.AsofDecember31,2015,AmerenMissourihad price-hedgedabout22%ofitsexpectednaturalgassupply requirementsforgenerationin2016.RenewableEnergyThestatesofIllinoisandMissourihaveenactedlawsrequiringelectricutilitiestoincluderenewableenergyresourcesintheirportfolios.Illinoisrequiredrenewable energyresourcestoequalorexceed2%ofthetotal electricitythatAmerenIllinoissuppliedtoitseligibleretail customersasofJune1,2008,withthatpercentage increasingto11.5%byJune1,2016,andto25%by June1,2025.Forthe2015planyear,AmerenIllinoismet itsrequirementthat10%ofitstotalelectricityforeligible retailcustomersbeprocuredfromrenewableenergy resources.Approximately77%ofthe2016planyear renewableenergyrequirementisexpectedtobemet throughlong-termagreementsthatAmerenIllinoishas enteredintotoobtainrenewableenergycreditsthrough 2032.Theremainingrequirementwillbemetthrough previousIPAprocurementsofadditionalrenewableenergy creditsandanIPAprocurementscheduledforspring2016.InMissouri,utilitiesarerequiredtopurchaseorgenerateelectricityequaltoatleast2%ofnativeloadsalesfromrenewablesources,withthatpercentageincreasingto atleast15%by2021,subjecttoa1%annuallimiton customerrateimpacts.Atleast2%ofeachrenewable energyportfoliorequirementmustbederivedfromsolar energy.In2015,AmerenMissourimetitsrequirementto purchaseorgenerateatleast5%ofitsnativeloadsales fromrenewableenergyresources.AmerenMissouriexpects tosatisfythenonsolarrequirementinto2018withits Keokukenergycenter,itsMarylandHeightsenergycenter, andthrougha102-megawattpowerpurchaseagreement withawindfarmoperator.TheMarylandHeightsenergy centergenerateselectricitybyburningmethanegas collectedfromalandfill.AmerenMissouriismeetingthe solarenergyrequirementthroughthepurchaseofsolar-generatedrenewableenergycreditsfromcustomer-installed systemsandfromitsownsolargenerationfromthe O'Fallonenergycenteranditsheadquartersbuilding.UnderthesameMissouristatutethatrequiresutilitiestopurchaseorgenerateelectricityfromrenewablesources, AmerenMissouriwasrequiredtoofferarebateprogramto provideanincentiveforcustomerstoinstallsolar generationontheirpremises.Inaccordancewiththestatute anda2013MoPSCorder,AmerenMissouriwasrequiredto provide$92millionofsolarrebatesby2020,whichhas beensubstantiallyfulfilled.Inits2013order,theMoPSC alsoauthorizedAmerenMissouritoemployatrackerto recordthecostsitincurredunderitssolarrebateprogram asaregulatoryasset.AmerenMissouriisrecoveringthe costsoftheserebates,alongwiththeestimated$9million incarryingcostoftheregulatoryasset,overathree-year periodbeginninginJune2015.EnergyEfficiencyAmerenMissouriandAmerenIllinoishaveimplementedenergyefficiencyprogramstoeducateandhelptheircustomersbecomemoreefficientusersofenergy.In Missouri,theMEEIAestablishedaregulatoryframeworkthat, amongotherthings,allowselectricutilitiestorecovercosts relatedtoMoPSC-approvedcustomerenergyefficiency programs.ThelawrequirestheMoPSCtoensurethata utility'sfinancialincentivesarealignedtohelpcustomersuse energymoreefficiently,toprovidetimelycostrecovery,and toprovideearningsopportunitiesassociatedwithcost-effectiveenergyefficiencyprograms.Missouridoesnothave alawmandatingenergyefficiencystandards.InAugust2012,theMoPSCapprovedAmerenMissouri'scustomerenergyefficiencyprograms,netshared benefits,andperformanceincentivefor2013through2015.

From2013through2015,AmerenMissouriinvested

$134millionincustomerenergyefficiencyprogramsand realized$174millionofnetsharedbenefits.TheMoPSC alsoestablishedaperformanceincentivethatwouldgive AmerenMissourithepotentialtoearnadditionalrevenues byachievingcertaincustomerenergyefficiencygoals, including$19millionif100%ofthegoalswereachieved duringthethree-yearperiod,withthepotentialtoearna largerperformanceincentiveifAmerenMissouri'senergy savingsexceededthosegoals.

12 InJune2015,theMoPSCstafffiledacomplaintcasewiththeMoPSCregardingthemethodandinputsusedincalculatingtheperformanceincentivefor2014and2015.In November2015,theMoPSCissuedanorderthatadopted theMoPSCstaff'smethodandinputsusedincalculating theperformanceincentivefor2014and2015.Ameren MissourifiledanappealoftheorderwiththeMissouri CourtofAppeals,WesternDistrict.IftheMissouriCourtof AppealsupholdstheMoPSCorder,theperformance incentivefromthe2014and2015MEEIAprogramswillbe significantlylessthantheperformanceincentivecalculated usingAmerenMissouri'sinterpretation.InFebruary2016,theMoPSCissuedanorderapprovingAmerenMissouri'sMarch2016toFebruary2019 MEEIAplan.SeeNote2-RateandRegulatoryMatters underPartII,Item8,ofthisreportforadditional

information.StatelawrequiresAmerenIllinoistooffercustomerenergyefficiencyprograms.Thelawalsoallowsfor recoveryoftheprograms'costs.TheICChasissuedorders approvingAmerenIllinois'electricandnaturalgasenergy efficiencyplansaswellasmechanismsbywhichprogram costscanberecoveredfromcustomers.Additionally,as partofitsIEIMAcapitalprojectinvestments,AmerenIllinois expectstoinvest$360millioninsmartgridinfrastructure from2012to2021,includingsmartmetersthatenable customerstoimprovetheirenergyefficiency.NATURALGASSUPPLYFORDISTRIBUTIONAmerenMissouriandAmerenIllinoisareresponsibleforthepurchaseanddeliveryofnaturalgastotheirutilitycustomers.AmerenMissouriandAmerenIllinoiseach developandmanageaportfolioofnaturalgassupply resources.Theseresourcesincludefirmgassupplyunder termagreementswithproducers,interstateandintrastate firmtransportationcapacity,firmno-noticestoragecapacity leasedfrominterstatepipelines,andon-systemstorage facilitiestomaintainnaturalgasdeliveriestocustomers throughouttheyear,andespeciallyduringpeakdemand periods.AmerenMissouriandAmerenIllinoisprimarilyuse PanhandleEasternPipeLineCompany,TrunklineGas Company,NaturalGasPipelineCompanyofAmerica, MississippiRiverTransmissionCorporation,Northern BorderPipelineCompany,andTexasEasternTransmission Corporationinterstatepipelinesystemstotransportnatural gastotheirsystems.Inadditiontotransactionsrequiring physicaldelivery,certainfinancialinstruments,including thoseenteredintointheNYMEXfuturesmarketandinthe OTCfinancialmarkets,areusedtohedgethepricepaidfor naturalgas.Naturalgaspurchasecostsarepassedonto customersofAmerenMissouriandAmerenIllinoisunder PGAclauses,subjecttoprudencereviewsbytheMoPSC andtheICC.AsofDecember31,2015,AmerenMissouri hadprice-hedged75%andAmerenIllinoishadprice-hedged97%oftheirexpected2016naturalgassupply

requirements.Foradditionalinformationonourfuelandpurchasedpowersupply,seeResultsofOperationsandLiquidityandCapitalResourcesinManagement'sDiscussionand AnalysisofFinancialConditionandResultsofOperations underPartII,Item7,ofthisreport.AlsoseeNote1-SummaryofSignificantAccountingPolicies,Note7-DerivativeFinancialInstruments,Note14-RelatedParty Transactions,andNote15-Commitmentsand ContingenciesunderPartII,Item8ofthisreport.INDUSTRYISSUESWearefacingissuescommontotheelectricandnaturalgasutilityindustry.Theseissuesinclude:

political,regulatory,andcustomerresistancetohigher rates;thepotentialforchangesinlaws,regulations,and policiesatthestateandfederallevels; corporatetaxlawchangesthatacceleratedepreciation deductions,whichreducecurrenttaxpaymentsand improvecashflow,butalsoresultinratebase reductionsandlimittheabilitytoclaimother deductionsandusecarryforwardtaxbenefits; cybersecurityrisks,includinglossofoperational controlofenergycentersandelectricandnaturalgas transmissionanddistributionsystemsand/orlossof data,suchasutilitycustomerdataandaccount

information; thepotentialformoreintensecompetitionin generation,supply,anddistribution,includingnew technologiesandtheirdecliningcosts; netmeteringrulesandotherchangesinexisting regulatoryframeworksandrecoverymechanismsto addresstheallocationofcoststocustomerswhoown generationresourcesthatenablethosecustomersto bothsellpowertoandtopurchasepowerfromus throughtheuseofourdistributionandtransmission

assets;pressureoncustomergrowthandusageinlightof economicconditionsandenergyefficiencyinitiatives; changesinthestructureoftheindustryasaresultof changesinfederalandstatelaws,includingthe formationandgrowthofindependenttransmission

entities;thelikelyreductionintheallowedreturnoncommon equityonFERC-regulatedelectrictransmissionassets; theavailabilityoffuelandfluctuationsinfuelprices; theavailabilityofqualifiedlaborandmaterial,andrising

costs;theavailabilityofaskilledworkforce,including retainingthespecializedskillsofthosewhoarenearing

retirement; regulatorylag; theinfluenceofmacroeconomicfactors,suchasyields onUnitedStatesTreasurysecuritiesandallowedrates ofreturnonequityprovidedbyregulators; higherlevelsofinfrastructureinvestmentsthatare expectedtoresultinnegativeordecreasedfreecash flows,definedascashflowsfromoperatingactivities lesscashflowsfrominvestingactivitiesanddividends

paid;publicconcernaboutthesitingofnewfacilities; 13 complexnewandproposedenvironmentallaws,regulations,andrequirements,includingairandwater qualitystandards,mercuryemissionsstandards,CCR managementrequirements,andCO 2limitations,whichmayreducethefrequencythatelectricgeneratingunits aredispatchedbasedupontheirCO 2 emissions; publicconcernaboutthepotentialimpactstothe environmentfromthecombustionoffossilfuels; aginginfrastructureandtheneedtoconstructnew powergeneration,transmission,anddistribution facilities,whichhavelongtimeframesforcompletion, withlittlelong-termabilitytopredictpowerand commoditypricesandregulatoryrequirements; legislationorproposalsforprogramstoencourageor mandateenergyefficiencyandrenewablesourcesof power,suchassolar,andthedebateoverwhoshould payforthoseprograms; publicconcernaboutnucleargeneration, decommissioningandthedisposalofnuclearwaste;

andconsolidationofelectricandnaturalgasutility

companies.Wearemonitoringtheseissues.Exceptasotherwisenotedinthisreport,weareunabletopredictwhatimpact,if any,theseissueswillhaveonourresultsofoperations, financialposition,orliquidity.Foradditionalinformation, seeRiskFactorsunderPartI,Item1A,Outlookin Management'sDiscussionandAnalysisofFinancial ConditionandResultsofOperationsunderPartII,Item7, Note2-RateandRegulatoryMatters,Note10-Callaway EnergyCenter,andNote15-Commitmentsand ContingenciesunderPartII,Item8,ofthisreport.

14 OPERATINGSTATISTICSThefollowingtablespresentkeyelectricandnaturalgasoperatingstatisticsforAmerenforthepastthreeyears:ElectricOperatingStatistics-YearEndedDecember31,201520142013ElectricSales-kilowatthours(inmillions):AmerenMissouri:

Residential

....................................................................

12,90313,64913,562 Commercial

...................................................................

14,57414,64914,634 Industrial

.....................................................................

8,2738,6008,709 Off-system

....................................................................

7,3806,1706,128 Other........................................................................

126 124 125AmerenMissouritotal

.........................................................

43,25643,19243,158AmerenIllinois:

ResidentialPowersupplyanddeliveryservice

...............................................

4,7974,6625,474Deliveryserviceonly

..........................................................

6,7577,2226,310 CommercialPowersupplyanddeliveryservice

...............................................

2,8372,5352,606Deliveryserviceonly

..........................................................

9,4439,6439,541 IndustrialPowersupplyanddeliveryservice

...............................................

1,5891,6741,613Deliveryserviceonly

..........................................................

10,27410,57610,861 Other........................................................................

524 518 522AmerenIllinoistotal

..........................................................

36,22136,83036,927Eliminateaffiliatesales

............................................................

(385)(67)(82)Amerentotal

................................................................

79,09279,95580,003ElectricOperatingRevenues(inmillions):

AmerenMissouri:

Residential

....................................................................$1,464$1,417$1,428 Commercial

...................................................................

1,2581,2031,216 Industrial

.....................................................................

469 475 491 Off-system

....................................................................

195 173 183 Other........................................................................

84 120 61AmerenMissouritotal

.........................................................$3,470$3,388$3,379AmerenIllinois:

ResidentialPowersupplyanddeliveryservice

...............................................$495$468$501Deliveryserviceonly

..........................................................

363 308 282 Commercial Powersupplyanddeliveryservice

...............................................

247 233 215Deliveryserviceonly

..........................................................

227 185 184 IndustrialPowersupplyanddeliveryservice

...............................................

71 87 68Deliveryserviceonly

..........................................................

53 42 44 Other........................................................................

227 199 167AmerenIllinoistotal

..........................................................$1,683$1,522$1,461 ATXI:Transmissionservices

...........................................................$70$33$19Otherandintercompanyeliminations

.................................................

(43)(30)(27)Amerentotal

................................................................$5,180$4,913$4,832 15 ElectricOperatingStatistics-YearEndedDecember31,201520142013ElectricGeneration-AmerenMissouri-kilowatthours(inmillions)

.........................

42,42443,47443,213Pricepertonofdeliveredcoal(average)-AmerenMissouri

...............................$37.88$37.36$36.19SourceofAmerenMissourienergysupply:

Coal.........................................................................

67.1%73.5%74.1%

Nuclear......................................................................

23.320.618.6 Hydroelectric

..................................................................

3.62.22.9Naturalgas

...................................................................

0.30.20.4Methanegasandsolar

..........................................................

0.20.10.1Purchased-Wind

..............................................................

0.70.80.7Purchased-Other

..............................................................

4.82.63.2 100.0%100.0%100.0%GasOperatingStatistics-YearEndedDecember31,201520142013NaturalGasSales-dekatherms(inmillions):AmerenMissouri:

Residential

....................................................................

7 88 Commercial

...................................................................

3 44 Industrial

.....................................................................

1 11 Transport.....................................................................

7 76AmerenMissouritotal

.........................................................

182019AmerenIllinois:

Residential

....................................................................

556662 Commercial

...................................................................

182321 Industrial

.....................................................................

3 36 Transport.....................................................................

899187AmerenIllinoistotal

..........................................................

165183176Amerentotal

................................................................

183203195NaturalGasOperatingRevenues(inmillions):

AmerenMissouri:

Residential

....................................................................$84$102$102 Commercial

...................................................................

344042 Industrial

.....................................................................

5 78Transportandother

.............................................................

14159AmerenMissouritotal

.........................................................$137$164$161AmerenIllinois:

Residential

....................................................................$550$675$611 Commercial

...................................................................

163208185 Industrial

.....................................................................

132326Transportandother

.............................................................

577025AmerenIllinoistotal

..........................................................$783$976$847Otherandintercompanyeliminations

.................................................

(2)-(2)Amerentotal

................................................................$918$1,140$1,006AVAILABLEINFORMATIONTheAmerenCompaniesmakeavailablefreeofchargethroughAmeren'swebsite(www.ameren.com)theirannualreportsonForm10-K,quarterlyreportsonForm10-Q, currentreportsonForm8-K,eXtensibleBusinessReporting Language(XBRL)documents,andanyamendmentsto thosereportsfiledwithorfurnishedtopursuanttoSections 13(a)or15(d)oftheExchangeActassoonasreasonably possibleaftersuchreportsareelectronicallyfiledwith,or furnishedto,theSEC.Thesedocumentsarealsoavailable throughanInternetwebsitemaintainedbytheSEC (www.sec.gov).Amerenalsousesitswebsiteasachannel ofdistributionformaterialinformationabouttheAmeren Companies.FinancialandothermaterialinformationregardingtheAmerenCompaniesisroutinelypostedtoand accessibleatAmeren'swebsite.TheAmerenCompaniesalsomakeavailablefreeofchargethroughAmeren'swebsitethechartersofAmeren's boardofdirectors'auditandriskcommittee,human resourcescommittee,nominatingandcorporate governancecommittee,financecommittee,andnuclear oversightandenvironmentalcommittee;thecorporate governanceguidelines;apolicyregardingcommunications totheboardofdirectors;apolicyandprocedureswith respecttorelated-persontransactions;acodeofethicsfor principalexecutiveandseniorfinancialofficers;acodeof businessconductapplicabletoalldirectors,officersand employees;andadirectornominationpolicythatappliesto 16 theAmerenCompanies.TheinformationonAmeren'swebsite,oranyotherwebsitereferencedinthisreport,is notincorporatedbyreferenceintothisreport.ITEM1A.RISKFACTORSInvestorsshouldreviewcarefullythefollowingmaterialriskfactorsandtheotherinformationcontainedinthisreport.TherisksthattheAmerenCompaniesfacearenot limitedtothoseinthissection.Theremaybefurtherrisks anduncertaintiesthatarenotpresentlyknownorthatare notcurrentlybelievedtobematerialthatmayadversely affecttheresultsofoperations,financialposition,and liquidityoftheAmerenCompanies.REGULATORYANDLEGISLATIVERISKSWearesubjecttoextensiveregulationofourbusinesses,whichcouldadverselyaffectourresultsofoperations,financialposition,andliquidity.Wearesubjecttoextensivefederal,state,andlocalregulation.Thisextensiveregulatoryframework,someof whichismorespecificallyidentifiedinthefollowingrisk factors,regulates,amongothermatters,theelectricand naturalgasutilityindustries;rateandcoststructureof utilities;operationofnuclearenergycenters;construction andoperationofgeneration,transmission,anddistribution facilities;acquisition,disposal,depreciationand amortizationofassetsandfacilities;transmissionreliability; andwholesaleandretailcompetition.Intheplanningand managementofouroperations,wemustaddressthe effectsofexistingandproposedlawsandregulationsand potentialchangesintheregulatoryframework,including initiativesbyfederalandstatelegislatures,RTOs,utility regulators,andtaxingauthorities.Significantchangesinthe natureoftheregulationofourbusinessescouldrequire changestoourbusinessplanningandmanagementofour businessesandcouldadverselyaffectourresultsof operations,financialposition,andliquidity.Failuretoobtain adequateratesorregulatoryapprovalsinatimelymanner; failuretoobtainnecessarylicensesorpermitsfrom regulatoryauthorities;theimpactofnewormodifiedlaws, regulations,standards,interpretations,orotherlegal requirements;orincreasedcompliancecostscould adverselyaffectourresultsofoperations,financialposition, andliquidity.Theelectricandnaturalgasratesthatweareallowedtochargearedeterminedthroughregulatory proceedings,whicharesubjecttointerventionand appeal,andarealsosubjecttolegislativeactions,which arelargelyoutsideofourcontrol.Anyeventsthatprevent usfromrecoveringourcostsorfromearningadequate returnsonourinvestmentscouldadverselyaffectour resultsofoperations,financialposition,andliquidity.Theratesthatweareallowedtochargeforourutilityservicessignificantlyinfluenceourresultsofoperations, financialposition,andliquidity.Theelectricandnaturalgas utilityindustriesareextensivelyregulated.Theutilityrateschargedtoourcustomersaredeterminedbygovernmental entities,includingtheMoPSC,theICC,andtheFERC.Many factorsinfluencedecisionsbytheseentities,includingthe costofprovidingservice,theprudencyofexpenditures,the qualityofservice,regulatorystaffknowledgeand experience,customerintervention,andeconomic conditionsaswellassocialandpoliticalviews.Decisions madebythesegovernmentalentitiesregardingratesare largelyoutsideofourcontrol.Weareexposedtoregulatory lagtovaryingdegreesbyjurisdiction,which,ifunmitigated, couldadverselyaffectourresultsofoperations,financial position,andliquidity.Rateordersarealsosubjectto appeal,whichcreatesadditionaluncertaintyastotherates thatwewillultimatelybeallowedtochargeforourservices.

Fromtimetotime,ourregulatorswillapprovetrackers, riders,orothermechanismsthatallowelectricornatural gasratestobeadjustedwithoutatraditionalrate proceeding.Thesemechanismsarenotpermanentand couldbechangedorterminated.AmerenMissouri'selectricandnaturalgasutilityratesandAmerenIllinois'naturalgasutilityratesaretypically establishedinregulatoryproceedingsthattakeupto 11monthstocomplete.AmerenMissouri'srates establishedinthoseproceedingsareprimarilybasedon historicalcostsandrevenues.AmerenIllinois'naturalgas ratesestablishedinthoseproceedingsmaybebasedon historicalorestimatedfuturecostsandrevenues.Thusthe ratesthatautilityisallowedtochargemaynotmatchits costsatanygiventime.Ratesincludeanallowedrateofreturnoninvestmentsestablishedbytheregulator.Althoughrateregulationis premisedonprovidinganopportunitytoearnareasonable rateofreturnoninvestedcapital,therecanbenoassurance thattheregulatorwilldeterminethatourcostswere prudentlyincurredorthattheregulatoryprocesswillresult inratesthatwillproducefullrecoveryofsuchcostsor provideforanopportunitytoearnareasonablereturnon thoseinvestments.Inyearswhencapitalinvestmentsandoperationscostsriseorcustomerusagedeclinesbelowthoselevels reflectedinrates,wemaynotbeabletoearntheallowed returnestablishedbytheregulator.Thiscouldresultinthe deferralorcancellationofplannedcapitalinvestments, whichcouldreducetheratebaseinvestmentsonwhichwe earnarateofreturn.Additionally,increasingratescould resultinregulatoryorlegislativeactions,aswellas competitiveorpoliticalpressures,allofwhichcould adverselyaffectourresultsofoperations,financialposition, andliquidity.Asaresultofitsparticipationintheperformance-basedformularatemakingprocessestablishedpursuant totheIEIMA,AmerenIllinois'returnonequityforits electricdistributionbusinessisdirectlycorrelatedto yieldsonUnitedStatesTreasurybonds.Additionally, AmerenIllinoisisrequiredtoachievecertain performancestandardsandcapitalspendinglevels.

Failuretomeettheserequirementscouldadverselyaffect 17 Ameren'sandAmerenIllinois'resultsofoperations,financialposition,andliquidity.AmerenIllinoisisparticipatingintheperformance-basedformularatemakingprocessestablishedpursuantto theIEIMAforitselectricdistributionbusiness.TheICC annuallyreviewsAmerenIllinois'ratefilingsunderthe IEIMAforreasonablenessandprudency.IftheICCwereto concludethatAmerenIllinois'incurredcostswerenot prudentlyincurred,theICCwoulddisallowrecoveryofsuch

costs.Thereturnonequitycomponentoftheformularateisequaltotheaverageforthecalendaryearofthemonthly yieldsof30-yearUnitedStatesTreasurybondsplus 580basispoints.Therefore,AmerenIllinois'annualreturnon equityundertheformularatemakingprocessforitselectric distributionbusinessisdirectlycorrelatedtotheyieldson suchbonds,whichareoutsideofAmerenIllinois'control.A 50basispointchangeintheaveragemonthlyyieldsofthe 30-yearUnitedStatesTreasurybondswouldresultinan estimated$6millionchangeinAmeren'sandAmerenIllinois' netincomebasedonits2016projectedratebase.AmerenIllinoisisalsosubjecttoperformancestandards.Failuretoachievethestandardswouldresultina reductioninthecompany'sallowedreturnonequity calculatedundertheformula.TheIEIMAprovidesforreturn onequitypenaltiestotaling34basispointsineachyear from2016through2018and38basispointsineachyear from2019through2022iftheperformancestandardsare notmet.Between2012and2021,AmerenIllinoisisrequiredtoinvest$625millionincapitalprojectsincrementaltoits averageelectricdeliverycapitalprojectsinvestmentsof

$228millionforcalendaryears2008through2010,inorder tomodernizeitsdistributionsystem.Unlessextendedthrough2022,theIEIMAperformance-basedformularatemakingprocesswillexpirein2019.When itexpires,AmerenIllinoiswillberequiredtoestablishfuture ratesthroughatraditionalrateproceedingwiththeICC, whichmightnotresultinratesthatproduceafullortimely recoveryofcostsorprovideforanadequatereturnon

investments.Wearesubjecttovariousenvironmentallawsandregulations.Significantcapitalexpendituresarerequired toachieveandtomaintaincompliancewiththeselaws andregulations.Failuretocomplywiththeselawsand regulationscouldresultinfacilityclosures,alterationsto themannerinwhichthesefacilitiesoperate,increased operatingcosts,orexposuretofinesandliabilities,allof whichcouldadverselyaffectourresultsofoperations, financialposition,andliquidity.Wearesubjecttovariousenvironmentallawsandregulationsenforcedbyfederal,state,andlocalauthorities.

Fromthebeginningphasesofsitinganddevelopmenttothe operationofelectricgeneration,transmissionand distributionfacilitiesandnaturalgasstorage,transmission anddistributionfacilities,ouractivitiesinvolvecompliancewithdiverseenvironmentallawsandregulations.These lawsandregulationsaddressemissions;dischargesto water;waterusage;impactstoair,land,andwater;and chemicalandwastehandling.Complexandlengthy processesarerequiredtoobtainandrenewapprovals, permits,orlicensesfornew,existing,ormodifiedfacilities.

Additionally,theuseandhandlingofvariouschemicalsor hazardousmaterialsrequirereleasepreventionplansand emergencyresponseprocedures.Wearealsosubjecttoliabilityunderenvironmentallawsthataddresstheremediationofenvironmental contaminationofpropertycurrentlyorformerlyownedby usorbyourpredecessors,aswellasproperty contaminatedbyhazardoussubstancesthatwegenerated.

SuchpropertiesincludeMGPsitesandthird-partysites, suchaslandfills.Additionally,privateindividualsmayseek toenforceenvironmentallawsandregulationsagainstus.

Theycouldallegeinjuryfromexposuretohazardous materials,seektocompelremediationofenvironmental contamination,orseektorecoverdamagesresultingfrom thatcontamination.TheEPAhaspromulgatedseveralenvironmentalregulationsthatwillhaveasignificantimpactontheelectric utilityindustry.Overtime,compliancewiththese regulationscouldbecostlyforcertaincompanies,including AmerenMissouri,thatoperatecoal-firedpowerplants.

SignificantnewrulesincludetheregulationofCO 2emissionsfromexistingpowerplantsthroughtheClean PowerPlanandfromnewpowerplantsthroughtherevised NSPS;theCSAPR,whichrequiresfurtherreductionsofSO 2emissionsandNO xemissionsfrompowerplants;aregulationgoverningmanagementandstorageofCCR;the MATS,whichrequirereductionofemissionsofmercury, toxicmetals,andacidgasesfrompowerplants;revised NSPSforparticulatematter,SO 2,andNO xemissionsfromnewsources;neweffluentstandardsapplicableto wastewaterdischargesfrompowerplants;andnew regulationsundertheCleanWaterActthatcouldrequire significantcapitalexpenditures,suchasmodificationsto waterintakestructuresornewcoolingtowersatAmeren Missouri'senergycenters.TheEPAalsoperiodically reviewsandrevisesnationalambientairqualitystandards, includingthosestandardsassociatedwithemissionsfrom powerplantssuchasparticulatematter,ozone,SO 2 and NO x.Certainofthesenewregulationsarebeingorarelikelytobechallengedthroughlitigation,sotheirultimate implementation,aswellasthetimingofanysuch implementation,isuncertain.Althoughmanydetailsof futureregulationsareunknown,individuallyorthe combinedeffectsofnewenvironmentalregulationscould resultinsignificantcapitalexpendituresandincreased operatingcostsforAmerenandAmerenMissouri.Amerenisalsosubjecttorisksfromchangingorconflictinginterpretationsofexistinglawsandregulations.

TheEPAisengagedinanenforcementinitiativeto determinewhethercoal-firedpowerplantsfailedtocomply withtherequirementsoftheNSRandNSPSprovisions undertheCleanAirActwhenthepowerplantsimplemented 18 modifications.InJanuary2011,theDepartmentofJustice,onbehalfoftheEPA,filedacomplaintintheUnitedStates DistrictCourtfortheEasternDistrictofMissourialleging thatAmerenMissouriviolatedprovisionsoftheCleanAir ActandMissourilaw.Anoutcomeinthismatteradverseto AmerenMissouricouldrequiresubstantialcapital expenditures,whichcannotbedeterminedatthistime.

Suchexpenditurescouldalsoaffectunitretirementand replacementdecisions.TheCleanPowerPlan,whichsetsforthCO 2 emissionsstandardsapplicabletoexistingpowerplants,wasissued bytheEPAbutstayedbytheUnitedStatesSupremeCourt pendingtheoutcomeofvariousappeals,asdiscussed below.IftheCleanPowerPlanisultimatelyupheldas issued,AmerenMissouriexpectstoincurincreasedfuel andoperatingcosts,andmakeneworacceleratedcapital expenditures,inadditiontothecostsofmaking modificationstoexistingoperationsinordertoachieve compliance.TheCleanPowerPlanrequiredMissouriand IllinoistoreduceCO 2emissionsfrompowerplantswithintheirstatessignificantlybelow2005levelsby2030.The rulecontainsinterimcomplianceperiodscommencingin 2022thatrequireeachstatetodemonstrateprogressin achievingitsCO 2reductiontarget.AmerenisevaluatingtheCleanPowerPlan'spotentialimpactstoitsoperations, includingthoserelatedtoelectricsystemreliability,andits levelofinvestmentincustomerenergyefficiencyprograms, renewableenergy,andotherformsofgeneration investment.Significantuncertaintyexistsregardingthe impactoftheCleanPowerPlan,asitsimplementationwill dependuponplanstobedevelopedbythestates.

Numerouslegalchallengesarependingwhichcouldresult intherulebeingdeclaredinvalidorthenatureandtimingof

CO 2emissionsreductionsbeingrevised.InFebruary2016,theUnitedStatesSupremeCourtstayedtheCleanPower Planandallimplementationrequirementsuntilsuchtimeas legalappealsareconcluded.Appealsarenotexpectedto concludepriorto2018.Wecannotpredicttheoutcomeof thelegalchallengesortheirimpactonourresultsof operations,financialposition,orliquidity.Iftheruleis ultimatelyupheldandimplementedinsubstantiallysimilar formtotherulewhenissued,compliancemeasurescould resultintheclosureoralterationoftheoperationofsome ofAmerenMissouri'scoalandnatural-gas-firedenergy centers,whichcouldresultinincreasedoperatingcosts.AmerenandAmerenMissourihaveincurredandexpecttoincursignificantcostsrelatedtoenvironmental complianceandsiteremediation.Neworrevised environmentalregulations,enforcementinitiatives,or legislationcouldresultinasignificantincreaseincapital expendituresandoperatingcosts,decreasedrevenues, increasedfinancingrequirements,penaltiesorfines,or reducedoperationsofsomeofAmerenMissouri'scoal-fired energycenters,which,inturn,couldleadtoincreased liquidityneedsandhigherfinancingcosts.Actionsrequired toensurethatourfacilitiesandoperationsarein compliancewithenvironmentallawsandregulationscould beprohibitivelyexpensiveifthecostsarenotfully recoveredthroughrates.EnvironmentallawscouldrequireAmerenMissouritocloseortoaltersignificantlythe operationofitsenergycenters.Moreover,ifAmeren Missourirequestsrecoveryofthesecapitalexpenditures andcoststhroughrates,theMoPSCcoulddenyrecoveryof alloraportionofthesecosts,preventtimelyrecovery,or makechangestotheregulatoryframeworkinaneffortto minimizeratevolatilityandcustomerrateincreases.Capital expendituresandcoststocomplywithfuturelegislationor regulationsthatarenotrecoverablethroughratesmight resultinAmerenMissouriclosingcoal-firedenergycenters earlierthanplanned,whichwouldleadtoanimpairmentof assetsandreducedrevenues.Weareunabletopredictthe ultimateimpactofthesemattersonourresultsof operations,financialposition,andliquidity.Wemaynotbeabletofullyutilizenetoperatingloss,taxcredit,orcharitablecontributioncarryforwards, whichcouldadverselyaffectourresultsofoperations, financialposition,andliquidity.Wehavesignificantlyreducedourconsolidatedfederalandstateincometaxobligationsinthepastthroughtax planningstrategies.Additionally,ourconsolidatedincome taxobligationshavebeenreducedduetothecontinueduse ofbonusdepreciationprovisionsthatallowforan accelerationofdeductionsfortaxpurposesandrecentIRS guidanceontaxdeductionsforrepairs.Weestimateour abilitytousetaxbenefits,includingthoseintheformofnet operatingloss,taxcreditandcharitablecontribution carryforwards,thatarerecordedasdeferredtaxassetson ourbalancesheets.Adisallowanceofthesetaxbenefits resultingfromalegislativechangeoradversedetermination byoneoftheapplicabletaxingjurisdictionscouldhavean adverseimpactonourresultsofoperations,financial position,andliquidity.Additionally,changesincorporate incometaxrateorpolicychangesaswellasanyinabilityto generateenoughtaxableincomeinthefuturetouseallof ourtaxbenefitsbeforetheyexpirecouldhaveanadverse impactonourresultsofoperations,financialposition,and

liquidity.Customers',legislators',andregulators'opinionsofusareaffectedbymanyfactors,includingsystem reliability,implementationofourinvestmentplans, protectionofcustomerinformation,rates,andmedia coverage.Totheextentthatcustomers,legislators,or regulatorshaveordevelopanegativeopinionofus,our resultsofoperations,financialposition,andliquidity couldbeadverselyaffected.Serviceinterruptionsduetofailuresofequipmentorfacilitiesasaresultofsevereordestructiveweatheror othercauses,andtheabilityofAmerenMissouriand AmerenIllinoistopromptlyrespondtosuchfailures,can affectcustomersatisfaction.Inadditiontosystemreliability issues,thesuccessofmodernizationefforts,suchasthose beingundertakenforAmerenIllinois'electricandnatural gasdeliverysystems,ourabilitytosafeguardsensitive customerinformation,andotheractionscanaffect customersatisfaction.Thetimingandmagnitudeofrate increasesandvolatilityofratescanalsoaffectcustomer satisfaction.Customers',legislators',andregulators' 19 opinionsofuscanalsobeaffectedbymediacoverage,includingtheproliferationofsocialmedia,whichmay includeinformation,whetherfactualornot,thatdamages ourbrandandreputation.Ifcustomers,legislators,orregulatorshaveordevelopanegativeopinionofusandourutilityservices,thiscould resultinincreasedregulatoryoversightandcouldaffectthe returnsoncommonequityweareallowedtoearn.

Additionally,negativeopinionsaboutuscouldmakeitmore difficultforourutilitiestoachievefavorablelegislativeor regulatoryoutcomes.Negativeopinionscouldalsoresultin salesvolumereductionsorincreaseduseofdistributed generation.Anyoftheseconsequencescouldadversely affectourresultsofoperations,financialposition,and

liquidity.Wearesubjecttofederalregulatorycomplianceandproceedings,whichexposesustothepotentialfor regulatorypenaltiesandothersanctions.TheFERCcanimposecivilpenaltiesof$1millionperviolationperdayforviolationofFERCstatutes,rules,and orders,includingmandatoryNERCreliabilitystandards.As ownersandoperatorsofbulkpowertransmissionsystems andelectricenergycenters,wearesubjecttomandatory NERCreliabilitystandards,includingcybersecurity standards.Compliancewiththesemandatoryreliability standardsmaysubjectustohigheroperatingcostsand mayresultinincreasedcapitalexpenditures.Ifwewere foundnottobeincompliancewiththesemandatory reliabilitystandardsortheFERCstatutes,rules,andorders, wecouldincursubstantialmonetarypenaltiesandother sanctions,whichcouldadverselyaffectourresultsof operations,financialposition,andliquidity.TheFERCalso conductsauditsandreviewsofAmerenMissouri's,Ameren Illinois',andATXI'saccountingrecordstoassessthe accuracyofitsformularatemakingprocessandhasthe abilitytorequireretroactiverefundstocustomersfor previouslybilledamounts,withinterest.OPERATIONALRISKSTheconstructionofandcapitalimprovementstoourelectricandnaturalgasutilityinfrastructureinvolvesubstantialrisks.Theserisksincludeescalatingcosts, unsatisfactoryperformancebytheprojectswhen completed,theinabilitytocompleteprojectsas scheduled,costdisallowancesbyregulators,andthe inabilitytoearnanadequatereturnoninvestedcapital, anyofwhichcouldresultinhighercostsandfacility

closures.Weexpecttoincursignificantcapitalexpendituresinordertomakeinvestmentstomaintainandimproveour electricandnaturalgasutilityinfrastructureandtocomply withexistingenvironmentalregulations.Weestimatethat wewillincurupto$11.5billion(AmerenMissouri-upto

$4.3billion;AmerenIllinois-upto$6.2billion;ATXI-up to$1.0billion)ofcapitalexpendituresduring2016through 2020,excludingtheimpactsoftheCleanPowerPlan.These estimatesincludeallowanceforequityfundsusedduringconstruction.InvestmentsinAmeren'srate-regulated operationsareexpectedtoberecoverablefromratepayers, butaresubjecttoprudencereviewsandareexposedto regulatorylagtovaryingdegreesbyjurisdiction.Ourabilitytocompleteconstructionprojectssuccessfullywithinprojectedestimatesiscontingentupon manyvariablesandsubjecttosubstantialrisks.These variablesinclude,butarenotlimitedto,project managementexpertiseandescalatingcostsformaterials, labor,andenvironmentalcompliance.Delaysinobtaining permits,shortagesinmaterialsandqualifiedlabor, suppliersandcontractorswhodonotperformasrequired undertheircontracts,changesinthescopeandtimingof projects,theinabilitytoraisecapitalonreasonableterms, orothereventsbeyondourcontrolcouldaffectthe schedule,cost,andperformanceoftheseprojects.With respecttocapitalexpendituresforpollutioncontrol equipment,thereisariskthatapowerplantmaynotbe permittedtocontinuetooperateifpollutioncontrol equipmentisnotinstalledbyprescribeddeadlinesordoes notperformasexpected.Shouldanysuchpollutioncontrol equipmentnotbeinstalledontimeorperformasexpected, AmerenMissouricouldbesubjecttoadditionalcostsandto thelossofitsinvestmentintheprojectorfacility.Allof theseprojectandconstructionriskscouldadverselyaffect ourresultsofoperations,financialposition,andliquidity.AmerenandAmerenIllinoismaynotbeabletoexecutetheirelectrictransmissioninvestmentplansorto realizetheexpectedreturnonthoseinvestments.Ameren,throughATXIandAmerenIllinois,isinvestingsignificantcapitalresourcesinelectrictransmission.These investmentsarebasedontheFERC'sregulatoryframework andarateofreturnoncommonequity,thatiscurrently higherthanthatallowedbyourstatecommissions.

However,theFERCregulatoryframeworkandrateofreturn issubjecttochange,includingchangesasaresultofthird-partycomplaintsandchallengesattheFERC.Theregulatory frameworkmaynotbeasfavorable,ortherateofreturn maybelower,inthefuture.Currently,theFERC-allowed returnoncommonequityforMISOtransmissionownersis 12.38%.InNovember2013,acomplaintcasewasfiled withtheFERCseekingareductionintheallowedreturnon commonequityundertheMISOtariff.InDecember2015,a FERCadministrativelawjudgeissuedaninitialdecisionin theNovember2013complaintcasethatwouldlowerthe allowedbasereturnoncommonequityto10.32%.The FERCisexpectedtoissueafinalorderontheNovember 2013complaintcasebyOctober2016.Asecondcomplaint casewasfiledinFebruary2015.Theoutcomeofthese complaintcasescouldnegativelyaffectAmerenIllinois'and ATXI'sallowedreturn.Anysuchreductionwouldalsoresult inarefundoftransmissionservicerevenuesearnedsince thefilingoftheinitialcomplaintcaseinNovember2013.As ofDecember31,2015,AmerenandAmerenIllinoishad currentregulatoryliabilitiesof$45millionand$32million, respectively,representingtheirestimatesofthepotential refundsfromtherefundeffectivedate.A50basispoint reductionintheFERC-allowedreturnoncommonequity 20 wouldreduceAmeren'sandAmerenIllinois'earningsbyanestimated$6millionand$3million,respectively,basedon eachcompany's2016projectedratebase.AsignificantportionofAmeren'selectrictransmissioninvestmentsconsistsofthreeseparateprojectstobe constructedbyATXI,whichhavebeenapprovedbyMISO asmulti-valueprojects.ThetotalinvestmentbyATXIinall threeprojectsisexpectedtobemorethan$1.6billion.The lastoftheseprojectsisexpectedtobecompletedin2019.

AfailurebyATXItocompletethesethreeprojectsontime andwithinprojectedcostestimatescouldadverselyaffect Ameren'sresultsofoperations,financialposition,and

liquidity.TheFERChasissuedorders,whicharesubjecttoongoinglitigation,eliminatingtherightoffirstrefusalforan electricutilitytoconstructwithinitsserviceterritorycertain newtransmissionprojectsforwhichtherewillberegional costsharing.Iftheseordersareupheldbythecourts, Amerenwouldneedtocompetetobuildcertainfuture electrictransmissionprojectsinitssubsidiaries'service territories.SuchcompetitioncouldlimitAmeren'sfuture transmissioninvestment.Conversely,ifsuchFERCorders arenotupheldbythecourts,therightoffirstrefusalwould beexpectedtobereinstated.Insuchevent,Amerenmay loseopportunitiesoutsideofitssubsidiaries'service territoriesandoutsideofMISOtoconstructelectric transmissionassets.Ourelectricgeneration,transmission,anddistributionfacilitiesaresubjecttooperationalrisksthat couldadverselyaffectourresultsofoperations,financial position,andliquidity.Ourfinancialperformancedependsonthesuccessfuloperationofelectricgeneration,transmission,and distributionfacilities.Operationofelectricgeneration, transmission,anddistributionfacilitiesinvolvesmanyrisks, including:

facilityshutdownsduetooperatorerrororafailureofequipmentorprocesses; longer-than-anticipatedmaintenanceoutages; aginginfrastructurethatmayrequiresignificant expenditurestooperateandmaintain; disruptionsinthedeliveryoffuel,failureofourfuel supplierstoprovideadequatequantitiesorqualityof fuel,orlackofadequateinventoriesoffuel,including ultra-low-sulfurcoalusedforAmerenMissouri's compliancewithenvironmentalregulations; lackofadequatewaterrequiredforcoolingplant

operations; labordisputes; inabilitytocomplywithregulatoryorpermit requirements,includingthoserelatingtoenvironmental

laws;disruptionsinthedeliveryofelectricitythataffectour

customers; handling,storage,anddispositionofCCR; unusualoradverseweatherconditionsorothernatural disasters,includingseverestorms,droughts,floods,tornadoes,earthquakes,solarflares,and electromagneticpulses; accidentsthatmightresultininjuryorlossoflife, extensivepropertydamage,orenvironmentaldamage; cybersecurityrisks,includinglossofoperational controlofAmerenMissouri'senergycentersandour transmissionanddistributionsystemsandlossofdata, suchascustomerdataandaccountinformation throughinsideroroutsideractions; failureofotheroperators'facilitiesandtheeffectofthat failureonourelectricsystemandcustomers; theoccurrenceofcatastrophiceventssuchasfires, explosions,actsofsabotageorterrorism,pandemic healthevents,orothersimilaroccurrences; limitationsonamountsofinsuranceavailabletocover lossesthatmightariseinconnectionwithoperatingour electricgeneration,transmission,anddistribution facilities;and otherunanticipatedoperationsandmaintenance expensesandliabilities.AmerenMissouri'sownershipandoperationofanuclearenergycentercreatesbusiness,financial,and wastedisposalrisks.AmerenMissouri'sownershipoftheCallawayenergycentersubjectsittotherisksassociatedwithnuclear generation,whichincludethefollowing:

potentialharmfuleffectsontheenvironmentandhumanhealthresultingfromtheoperationofnuclear facilitiesandthestorage,handling,anddisposalof radioactivematerials; continueduncertaintyregardingthefederal government'splantopermanentlystorespentnuclear fuelandtheriskofbeingrequiredtoprovideforlong-termstorageofspentnuclearfuelattheCallaway energycenter; limitationsontheamountsandtypesofinsurance availabletocoverlossesthatmightariseinconnection withtheCallawayenergycenterorotherUnitedStates nuclearfacilities; uncertaintieswithrespecttocontingenciesand retrospectivepremiumassessmentsrelatingtoclaims attheCallawayenergycenteroranyotherUnited Statesnuclearfacilities; publicandgovernmentalconcernsabouttheadequacy ofsecurityatnuclearfacilities; uncertaintieswithrespecttothetechnologicaland financialaspectsofdecommissioningnuclearfacilities attheendoftheirlicensedlives; limitedavailabilityoffuelsupply; costlyandextendedoutagesforscheduledor unscheduledmaintenanceandrefueling;and potentialadverseeffectsofanaturaldisaster,actsof sabotageorterrorism,oranyaccidentleadingto releaseofnuclearcontamination.TheNRChasbroadauthorityunderfederallawtoimposelicensingandsafetyrequirementsfornuclear facilities.Intheeventofnoncompliance,theNRChasthe authoritytoimposefinesortoshutdownaunit,orboth, 21 dependinguponitsassessmentoftheseverityofthesituation,untilcomplianceisachieved.Revisedsafety requirementspromulgatedfromtimetotimebytheNRC couldnecessitatesubstantialcapitalexpendituresatnuclear facilitiessuchastheCallawayenergycenter.Inaddition,ifa seriousnuclearincidentweretooccur,itcouldadversely affectAmeren'sandAmerenMissouri'sresultsof operations,financialcondition,andliquidity.Amajor incidentatanuclearfacilityanywhereintheworldcould causetheNRCtolimitorprohibittheoperationofany domesticnuclearunitandcouldalsocausetheNRCto imposeadditionalconditionsorrequirementsonthe industry,whichcouldincreasecostsandresultinadditional capitalexpenditures.NRCstandardsrelatingtoseismicrisk requireAmerenMissouritofurtherevaluatetheimpactof anearthquakeonitsCallawayenergycenterdueits proximitytoafaultline,whichcouldrequiretheinstallation ofadditionalcapitalequipment.Ournaturalgasdistributionandstorageactivitiesinvolvenumerousrisksthatmayresultinaccidentsand otheroperatingrisksandcoststhatcouldadverselyaffect ourresultsofoperations,financialposition,andliquidity.Inherentinournaturalgasdistributionandstorageactivitiesareavarietyofhazardsandoperatingrisks,such asleaks,accidentalexplosions,mechanicalproblemsand cybersecurityrisks,whichcouldcausesubstantialfinancial losses.Inaddition,thesehazardscouldresultinserious injury,lossofhumanlife,significantdamagetoproperty, environmentalimpacts,andimpairmentofouroperations, whichinturncouldleadustoincursubstantiallosses.In accordancewithcustomaryindustrypractice,wemaintain insuranceagainstsome,butnotall,oftheserisksand losses.Thelocationofdistributionmainsandstorage facilitiesnearpopulatedareas,includingresidentialareas, businesscenters,industrialsites,andotherpublic gatheringplaces,couldincreasethelevelofdamages resultingfromtheserisks.Amajordomesticincident involvingnaturalgassystemscouldleadtoadditional capitalexpendituresandincreasedregulationofnaturalgas utilities.Theoccurrenceofanyoftheseeventscould adverselyaffectourresultsofoperations,financialposition, andliquidity.Significantportionsofourelectricgeneration,transmission,anddistributionfacilitiesandnaturalgas transmissionanddistributionfacilitiesareaging.This aginginfrastructuremayrequireadditionalmaintenance expendituresormayrequirereplacement,whichcould adverselyaffectourresultsofoperations,financial position,andliquidity.Ouraginginfrastructuremayposeriskstosystemreliabilityandexposeustoexpeditedorunplannedcapital expendituresandoperatingcosts.AllofAmerenMissouri's coal-firedenergycenterswereconstructedpriorto1978, andtheCallawaynuclearenergycenterbeganoperatingin 1984.Theageoftheseenergycentersincreasestherisksof unplannedoutages,reducedgenerationoutput,andhigher maintenanceexpense.If,attheendofitslife,anenergycenter'scosthasnotbeenfullyrecovered,AmerenMissouri maybeadverselyaffectedifsuchcostisnotallowedin ratesbytheMoPSC.Agingtransmissionanddistribution facilitiesaremorepronetofailurethannewfacilities,which resultsinhighermaintenanceexpenseandtheneedto replacethesefacilitieswithnewinfrastructure.Evenifthe systemisproperlymaintained,itsreliabilitymayultimately deteriorateandnegativelyaffectourabilitytoserveour customers,whichcouldresultinadditionaloversightbyour regulators.Thefrequencyanddurationofcustomeroutages areIEIMAperformancestandardsandtherefore,ifthese standardsarenotachieved,itwillresultinareductionin AmerenIllinois'allowedreturnonequity.Thehigher maintenancecostsassociatedwithaginginfrastructureand capitalexpendituresfornewreplacementinfrastructure couldcauseadditionalratevolatilityforourcustomers, resistancebyourregulatorstoallowcustomerrate increases,and/orregulatorylaginsomeofour jurisdictions,anyofwhichcouldadverselyaffectourresults ofoperations,financialposition,andliquidity.Energyconservation,energyefficiency,distributedgeneration,energystorage,andotherfactorsthatreduce energydemandcouldadverselyaffectourresultsof operations,financialposition,andliquidity.Requirementsandincentivestoreduceenergyconsumptionhavebeenproposedbyregulatoryagencies andintroducedbylegislatures.Conservationandenergy efficiencyprogramsaredesignedtoreduceenergydemand.

Withoutaregulatorymechanismtoensurerecovery,a declineinusagewillresultinanunder-recoveryofour revenuerequirement.AmerenMissouri,evenifitsponsors customerenergyefficiencyprogramsundertheMEEIA,is exposedtodecliningusagelossesfromenergyefficiency effortsnotrelatedtoitsspecificprograms,aswellasfrom distributedgenerationsourcessuchassolarpanels.

Additionally,macroeconomicfactorsresultinginlow economicgrowthorcontractionwithinourservice territoriescouldreduceenergydemand.Technologicaladvancescouldreduceorchangecustomerelectricityconsumption.AmerenMissouri generatespoweratutility-scaleenergycenterstoachieve economiesofscaleandtoproducepoweratacompetitive cost.Somedistributedgenerationtechnologieshave becomemorecost-competitive,withdecreasingcosts expectedinthefuture.Weexpectthatthecostsofthese distributedgenerationtechnologieswilldeclineovertimeto alevelthatiscompetitivewiththatofAmerenMissouri's energycenters.Additionally,technologicaladvancesrelated toenergystoragemaybecoupledwithdistributed generationtoreducethedemandforourelectricutility services.Increasedadoptionofthesetechnologiescould decreaseourrevenuesifcustomersceasetouseour generation,transmission,anddistributionservicesat currentlevels.AmerenMissouriandAmerenIllinoismight incurstrandedcosts,whichultimatelymightnotbe recoveredthroughrates.

22 Wearesubjecttoemployeeworkforcefactorsthatcouldadverselyaffectouroperations.Ourbusinessesdependuponourabilitytoemployandretainkeyofficersandotherskilledprofessionalandtechnicalemployees.Asignificantportionofourworkforce isnearingretirement,includingmanyemployeeswith specializedskills,suchasmaintainingandservicingour electricandnaturalgasinfrastructureandoperatingour energycenters.Wearealsosubjecttocollectivebargaining agreementsthatcollectivelyrepresentabout54%of Ameren'stotalemployees.Anyworkstoppageexperienced inconnectionwithnegotiationsofcollectivebargaining agreementscouldadverselyaffectouroperations.Ouroperationsaresubjecttoactsofsabotage,war,terrorism,cyberattacks,andotherintentionally disruptiveacts.Likeotherelectricandnaturalgasutilities,ourenergycenters,fuelstoragefacilities,transmissionanddistribution facilities,andinformationsystemsmaybetargetsof terroristactivities,includingcyberattacks,whichcould disruptourabilitytoproduceordistributeourenergy products.Anysuchdisruptioncouldresultinasignificant decreaseinrevenuesorsignificantcostsforrepair,which couldadverselyaffectourresultsofoperations,financial position,andliquidity.Ourindustryhasseenanincreaseinvolumeandsophisticationofcybersecurityincidentsfrominternational activistorganizations,countries,andindividuals.Asecurity breachatourphysicalassetsorininformationsystems couldaffectthereliabilityofthetransmissionand distributionsystem,disruptelectricgeneration,and/or subjectustofinancialharmassociatedwiththeftor inappropriatereleaseofcertaintypesofinformation, includingsensitivecustomerandemployeedata.Ifa significantbreachoccurred,ourreputationcouldbe adverselyaffected,customerconfidencecouldbe diminished,orwecouldbesubjecttolegalclaims,anyof whichcouldresultinasignificantdecreaseinrevenuesor significantcostsforremedyingtheimpactsofsucha breach.Ourgeneration,transmission,anddistribution systemsarepartofaninterconnectedsystem.Therefore,a disruptioncausedbyacybersecurityincidentatanother utility,electricgenerator,RTO,orcommoditysuppliercould alsoadverselyaffectourbusinesses.Wemaintain insuranceagainstsome,butnotall,oftheserisksand losses.Inaddition,newregulationscouldrequirechanges inoursecuritymeasuresandcouldadverselyaffectour resultsofoperations,financialposition,andliquidity.FINANCIAL,ECONOMIC,ANDMARKETRISKSOurbusinessesaredependentonourabilitytoaccessthecapitalmarketssuccessfully.Wemightnothaveaccesstosufficientcapitalintheamountsandat thetimesneeded.Werelyonshort-termandlong-termdebtassignificantsourcesofliquidityandfundingforcapitalrequirementsnotsatisfiedbyouroperatingcashflow,as wellastorefinancelong-termdebt.Theinabilitytoraise debtorequitycapitalonreasonableterms,oratall,could negativelyaffectourabilitytomaintainandtoexpandour businesses.Eventsbeyondourcontrol,suchasarecession orextremevolatilityinthedebt,equity,orcreditmarkets, mightcreateuncertaintythatcouldincreaseourcostof capitalorimpairoreliminateourabilitytoaccessthedebt, equity,orcreditmarkets,includingourabilitytodrawon bankcreditfacilities.Anyadversechangeinourcredit ratingscouldreduceaccesstocapitalandtriggeradditional collateralpostingsandprepayments.Suchchangescould alsoincreasethecostofborrowingandfuel,power,and naturalgassupply,amongotherthings,whichcould adverselyaffectourresultsofoperations,financialposition, andliquidity.CertainAmerensubsidiaries,suchasATXI, relyonAmerenforaccesstocapital.Circumstancesthat limitAmeren'saccesstocapitalcouldimpairitsabilityto providethosesubsidiarieswithneededcapital.Ameren'sholdingcompanystructurecouldlimititsabilitytopaycommonstockdividendsandtoserviceits debtobligations.Amerenisaholdingcompany;therefore,itsprimaryassetsareitsinvestmentsinthecommonstockofits subsidiaries,includingAmerenMissouri,AmerenIllinois, andATXI.Asaresult,Ameren'sabilitytopaydividendson itscommonstockdependsontheearningsofits subsidiariesandtheabilityofitssubsidiariestopay dividendsorotherwisetransferfundstoAmeren.Similarly, Ameren'sabilitytoserviceitsdebtobligationsisdependent upontheearningsofoperatingsubsidiariesandthe distributionofthoseearningsandotherpayments, includingpaymentsofprincipalandinterestunder intercompanyindebtedness.Thepaymentofdividendsto Amerenbyitssubsidiariesinturndependsontheirresults ofoperationsandavailablecashandotheritemsaffecting retainedearnings.Ameren'ssubsidiariesareseparateand distinctlegalentitiesandhavenoobligation,contingentor otherwise,topayanydividendsormakeanyother distributions(exceptforpaymentsrequiredpursuanttothe termsofintercompanyborrowingarrangementsandcash paymentsunderthetaxallocationagreement)toAmeren.

Certainfinancingagreements,corporateorganizational documents,andcertainstatutoryandregulatory requirementsmayimposerestrictionsontheabilityof AmerenMissouri,AmerenIllinois,andATXItotransfer fundstoAmerenintheformofcashdividends,loans,or

advances.Noranda'sbankruptcyfiling,theexpectedcurtailmentofoperationsatitsaluminumsmelter,and theresultingsignificantreductioninsalesvolumesto NorandawilladverselyaffectAmeren'sandAmeren Missouri'sresultsofoperations,financialcondition,and

liquidity.AmerenMissourisupplieselectricitytoNoranda'saluminumsmelterinsoutheastMissouriunderalong-term powersupplycontract.InitsApril2015electricrateorder, theMoPSCapprovedaratedesignthatestablished 23

$78millioninannualrevenues,netoffuelandpurchasedpowercosts,asNoranda'sportionofAmerenMissouri's revenuerequirement.TheportionofAmerenMissouri's annualrevenuerequirementreflectedinNoranda'selectric rateisbasedontheassumptionthatthesmelterwilluse approximately4.2millionmegawatthoursannually,whichis almost100%ofitsoperatingcapacity.OnJanuary8,2016,Norandaannouncedthatproductionhadbeenidledattwoofitsthreepotlinesatthe smelterfollowinganelectricsupplycircuitfailureonassets notownedbyAmerenMissouri.OnJanuary13,2016, Norandaannouncedthatthesmelter's"remaining operationswillbecurtailedonorbeforeMarch12,2016, unless[Noranda]isabletosecureasubstantiallymore sustainablepowerrateforthesmelterandmaterially improve[Noranda's]overallliquidity."OnFebruary8,2016, Norandafiledvoluntarypetitionsforacourt-supervised restructuringprocessunderChapter11oftheUnitedStates BankruptcyCode.Inthefiling,Norandareaffirmedthatthe remainingpotlinewillcontinuetooperateatthesmelter untilMarch2016,atwhichtimeoperationofthelinewillbe curtailed.Norandastateditwouldmaintaintheflexibilityto restartoperationsatthesmeltershouldconditionsallow.Asaresultoftheseeventsin2016,actualsalesvolumestoNorandawillbesignificantlybelowthesales volumesreflectedinratesandtherefore,AmerenMissouri willnotfullyrecoveritsrevenuerequirementuntilratesare adjustedbytheMoPSCinafutureelectricratecaseto accuratelyreflectNoranda'sactualsalesvolumes.Inlightof theNorandaannouncementsdescribedabove,Ameren MissouriexpectstoemployaprovisioninitsFACtariffthat, undercertaincircumstances,allowsAmerenMissourito retainaportionofanyrevenuesfromanyoff-systemsales itmakesasaresultofthereducedtariffsalestoNoranda.

ThecurrentmarketpriceofelectricityislessthanNoranda's electricrate,andAmerenMissouriexpectsmarketpricesto remainbelowNoranda'selectricrateduring2016.

Accordingly,thisFACprovisionwouldnotenableAmeren Missouritofullyrecoveritsrevenuerequirementunder currentmarketconditions.AmerenMissouriwillcontinuetomonitorNoranda'ssalesvolumesandevaluateitsregulatoryandlegislative optionstomitigateadversefinancialimpacts.Thereduction inNoranda'ssalesvolumeswilladverselyaffectAmeren's andAmerenMissouri'sresultsofoperations,financial condition,andliquidityuntilcustomerratesareadjustedin afutureratecase.Increasingcostsassociatedwithourdefinedbenefitretirementandpostretirementplans,healthcareplans, andotheremployeebenefitscouldadverselyaffectour financialpositionandliquidity.Amerenoffersdefinedbenefitpensionandpostretirementbenefitplanscoveringsubstantiallyallofits unionemployees.Amerenoffersdefinedbenefitpension planscoveringsubstantiallyallofitsnon-unionemployees andpostretirementbenefitplanscoveringnon-union employeeshiredbeforeOctober2015.Assumptionsrelated tofuturecosts,returnsoninvestments,interestrates, timingofemployeeretirements,andmortality,aswellas otheractuarialmatters,haveasignificantimpactonour customers'ratesandourplanfundingrequirements.

Ameren'stotalunfundedobligationunderitspensionand postretirementbenefitplanswas$567millionasof December31,2015.Amerenexpectstofunditspension plansatalevelequaltothegreaterofthepensionexpense orthelegallyrequiredminimumcontribution.Considering Ameren'sassumptionsatDecember31,2015,its investmentperformancein2015,anditspensionfunding policy,Amerenexpectstomakeannualcontributionsof

$40millionto$70millionineachofthenextfiveyears, withaggregateestimatedcontributionsof$280million.We expectAmerenMissouri'sandAmerenIllinois'portionsof thefuturefundingrequirementstobe40%and50%,

respectively.Theseamountsareestimates.Theymay changewithactualinvestmentperformance,changesin interestrates,changesinourassumptions,changesin governmentregulations,andanyvoluntarycontributions.Inadditiontothecostsofourretirementplans,thecostsofprovidinghealthcarebenefitstoouremployees andretireeshaveincreasedinrecentyears.Webelievethat ouremployeebenefitcosts,includingcostsofhealthcare plansforouremployeesandformeremployees,will continuetorise.Theincreasingcostsandfunding requirementsassociatedwithourdefinedbenefitretirement plans,healthcareplans,andotheremployeebenefitscould increaseourfinancingneedsandotherwiseadverselyaffect ourfinancialpositionandliquidity.ITEM1B.UNRESOLVEDSTAFFCOMMENTS None.24 ITEM2.PROPERTIESForinformationonourprincipalproperties,seetheenergycentertablebelow.SeealsoLiquidityandCapitalResourcesandRegulatoryMattersinManagement'sDiscussionandAnalysisofFinancialConditionandResultsofOperationsunderPartII,Item7,ofthisreportforadiscussionofplannedadditions,replacementsortransfers.SeealsoNote5-Long-term DebtandEquityFinancings,andNote15-CommitmentsandContingenciesunderPartII,Item8,ofthisreport.ThefollowingtableshowstheanticipatedcapabilityofAmerenMissouri'senergycentersatthetimeofAmerenMissouri'sexpected2016peaksummerelectricaldemand:PrimaryFuelSourceEnergyCenter LocationNetKilowattCapability (a)Coal......................................LabadieFranklinCounty,Missouri2,372,000RushIslandJeffersonCounty,Missouri1,178,000SiouxSt.CharlesCounty,Missouri970,000MeramecSt.LouisCounty,Missouri591,000Totalcoal..................................

5,111,000 Nuclear....................................CallawayCallawayCounty,Missouri1,193,000 Hydroelectric

...............................OsageLakeside,Missouri240,000KeokukKeokuk,Iowa140,000Totalhydroelectric

...........................

380,000 Pumped-storage

............................TaumSaukReynoldsCounty,Missouri440,000Oil(CTs)...................................MeramecSt.LouisCounty,Missouri54,000FairgroundsJeffersonCity,Missouri54,000MexicoMexico,Missouri53,000MoberlyMoberly,Missouri53,000MoreauJeffersonCity,Missouri53,000Totaloil...................................

267,000Naturalgas(CTs)

............................

Audrain (b)AudrainCounty,Missouri 600,000 Venice (c)Venice,Illinois 487,000GooseCreekPiattCounty,Illinois 432,000 PinckneyvillePinckneyville,Illinois 316,000RaccoonCreekClayCounty,Illinois 300,000 Meramec (c)(d)St.LouisCounty,Missouri 282,000 Kinmundy (c)Kinmundy,Illinois 206,000PenoCreek (b)(c)BowlingGreen,Missouri 188,000 KirksvilleKirksville,Missouri 13,000Totalnaturalgas

............................

2,824,000Methanegas(CT)

............................MarylandHeightsMarylandHeights,Missouri 8,000 Solar.....................................

O'FallonO'Fallon,Missouri 3,000TotalAmerenandAmerenMissouri

............

10,226,000(a)Netkilowattcapabilityisthegeneratingcapacityavailablefordispatchfromtheenergycenterintotheelectrictransmissiongrid.(b)ThereareeconomicdevelopmentleasearrangementsapplicabletotheseCTs.

(c)TheseCTshavethecapabilitytooperateoneitheroilornaturalgas(dualfuel).

(d)IncludescapabilityoftwocoalunitsthatwillburnnaturalgasbeginninginApril2016.Thefollowingtablepresentsin-serviceelectricandnaturalgasutility-relatedpropertiesforAmerenMissouriandAmerenIllinoisasofDecember31,2015:

Ameren Missouri Ameren IllinoisCircuitmilesofelectrictransmissionlines (a)...2,9574,569Circuitmilesofelectricdistributionlines

......33,25245,881Percentageofcircuitmilesofelectricdistributionlinesunderground...........23%15%Milesofnaturalgastransmissionanddistributionmains

.....................3,33018,294Undergroundgasstoragefields.............-12Totalworkingcapacityofundergroundgasstoragefieldsinbillioncubicfeet.........-24(a)ATXIowns29milesoftransmissionlinesnotreflectedinthis table.Ourotherpropertiesincludeofficebuildings,warehouses,garages,andrepairshops.Withonlyafewexceptions,wehavefeetitletoallprincipalenergycentersandotherunitsofpropertymaterial totheoperationofourbusinesses,andtotherealproperty onwhichsuchfacilitiesarelocated(subjecttomortgage lienssecuringouroutstandingfirstmortgagebondsandto certainpermittedliensandjudgmentliens).Theexceptions areasfollows:

AportionofAmerenMissouri'sOsageenergycenterreservoir,certainfacilitiesatAmerenMissouri'sSioux energycenter,mostofAmerenMissouri'sPenoCreek andAudrainCTenergycenters,certainsubstations, andmosttransmissionanddistributionlinesand naturalgasmainsaresituatedonlandsoccupiedunder leases,easements,franchises,licenses,orpermits.The 25 UnitedStatesorthestateofMissourimayownormayhaveparamountrightstocertainlandslyinginthebed oftheOsageRiverorlocatedbetweentheinnerand outerharborlinesoftheMississippiRiveronwhich certainofAmerenMissouri'senergycentersandother propertiesarelocated.

TheUnitedStates,thestateofIllinois,thestateofIowa, orthecityofKeokuk,Iowa,mayownormayhave paramountrightswithrespecttocertainlandslyingin thebedoftheMississippiRiveronwhichaportionof AmerenMissouri'sKeokukenergycenterislocated.SubstantiallyallofthepropertiesandplantofAmerenMissouriandAmerenIllinoisaresubjecttothefirstliensof theindenturessecuringtheirmortgagebonds.AmerenMissourihasconveyedmostofitsPenoCreekCTenergycentertothecityofBowlingGreen,Missouri, andleasedtheenergycenterbackfromthecitythrough 2022.Underthetermsofthiscapitallease,Ameren Missouriisresponsibleforalloperationandmaintenance fortheenergycenter.Ownershipoftheenergycenterwill transfertoAmerenMissouriattheexpirationofthelease,at whichtimethepropertyandplantwillbecomesubjectto thelienofanyAmerenMissourifirstmortgagebond indenturethenineffect.AmerenMissourioperatesaCTenergycenterlocatedinAudrainCounty,Missouri.AmerenMissourihasrights andobligationsaslesseeoftheCTenergycenterundera long-termleasewithAudrainCounty.Theleasewillexpire onDecember1,2023.Underthetermsofthiscapitallease, AmerenMissouriisresponsibleforalloperationand maintenancefortheenergycenter.Ownershipoftheenergy centerwilltransfertoAmerenMissouriattheexpirationof thelease,atwhichtimethepropertyandplantwillbecome subjecttothelienofanyAmerenMissourifirstmortgage bondindenturethenineffect.ITEM3.LEGALPROCEEDINGSWeareinvolvedinlegalandadministrativeproceedingsbeforevariouscourtsandagencieswith respecttomattersthatariseintheordinarycourseof business,someofwhichinvolvesubstantialamountsof money.Webelievethatthefinaldispositionofthese proceedings,exceptasotherwisedisclosedinthisreport, willnothaveamaterialadverseeffectonourresultsof operations,financialposition,orliquidity.Riskoflossis mitigated,insomecases,byinsuranceorcontractualor statutoryindemnification.Webelievethatwehave establishedappropriatereservesforpotentiallosses.

Materiallegalandadministrativeproceedings,whichare discussedinNote2-RateandRegulatoryMatters, Note10-CallawayEnergyCenterandNote15-CommitmentandContingenciesunderPartII,Item8,of thisreportandareincorporatedhereinbyreference,include thefollowing:

AmerenMissouri'sappealtotheMissouriCourtofAppeals,WesternDistrict,regardingthemethodand inputsusedtocalculateitsperformanceincentive underMEEIAfor2014and2015; ATXI'srequestforacertificateofconvenienceand necessityfromtheMoPSCfortheMarkTwainproject; thecomplaintcasesfiledwiththeFERCseekinga reductionintheallowedbasereturnoncommonequity undertheMISOtariff; theEPA'sCleanAirAct-relatedlitigationagainst AmerenMissouri; remediationmattersassociatedwithformerMGPand wastedisposalsitesoftheAmerenCompanies; asbestos-relatedlitigationassociatedwiththeAmeren Companies;and classactionlawsuitagainstAmerenMissourirelatingto municipaltaxes.

26 ITEM4.MINESAFETYDISCLOSURESNotapplicable.EXECUTIVEOFFICERSOFTHEREGISTRANTS(ITEM401(b)OFREGULATIONS-K):TheexecutiveofficersoftheAmerenCompanies,includingmajorsubsidiaries,arelistedbelow,alongwiththeiragesasofDecember31,2015,allpositionsandofficesheldwiththeAmerenCompaniesasofFebruary15,2016,tenureasofficer,andbusinessbackgroundforatleastthelastfiveyears.SomeexecutiveofficersholdmultiplepositionswithintheAmeren Companies;theirtitlesaregiveninthedescriptionoftheirbusinessexperience.AMERENCORPORATION:

NameAgePositionsandOfficesHeldWarnerL.Baxter54Chairman,PresidentandChiefExecutiveOfficer,andDirectorBaxterjoinedAmerenMissouriin1995.Baxterwaselectedtothepositionsofexecutivevicepresidentandchieffinancial officerofAmeren,AmerenMissouri,AmerenIllinois,andAmerenServicesin2003.Hewaselectedchairman,president,chief executiveofficer,andchieffinancialofficerofAmerenServicesin2007.In2009,Baxterwaselectedchairman,presidentand chiefexecutiveofficerofAmerenMissouri.InFebruary2014,BaxterwaselectedpresidentofAmerenandwasappointedto theAmerenboard.InApril2014,herelinquishedhispositionsatAmerenMissouriandwaselectedchiefexecutiveofficerof Ameren.InJuly2014,BaxterwaselectedchairmanoftheAmerenboard.MartinJ.Lyons,Jr.49ExecutiveVicePresidentandChiefFinancialOfficerLyonsjoinedAmerenServicesin2001.In2008,Lyonswaselectedseniorvicepresidentandprincipalaccountingofficerof theAmerenCompanies.In2009,LyonswasalsoelectedchieffinancialofficeroftheAmerenCompanies.In2013,Lyonswas electedexecutivevicepresidentandchieffinancialofficeroftheAmerenCompanies,andrelinquishedhisdutiesasprincipal accountingofficer.LyonshasalsobeenelectedchairmanandpresidentofAmerenServices,effectiveupontheretirementof DanielF.ColeonMarch1,2016.GregoryL.Nelson58SeniorVicePresident,GeneralCounsel,andSecretaryNelsonjoinedAmerenMissouriin1995.NelsonwaselectedvicepresidentandtaxcounselofAmerenServicesin1999and vicepresidentofAmerenMissouriandAmerenIllinoisin2003.In2010,Nelsonwaselectedvicepresident,taxanddeputy generalcounselofAmerenServices.HeremainedvicepresidentofAmerenMissouriandAmerenIllinois.In2011,Nelsonwas electedseniorvicepresident,generalcounselandsecretaryoftheAmerenCompanies.BruceA.Steinke54SeniorVicePresident,Finance,andChiefAccountingOfficerSteinkejoinedAmerenServicesin2002.In2008,hewaselectedvicepresidentandcontrollerofAmeren,AmerenIllinois,and AmerenServices.In2009,SteinkerelinquishedhispositionsatAmerenIllinois.In2013,Steinkewaselectedseniorvice president,finance,andchiefaccountingofficeroftheAmerenCompanies.

27 SUBSIDIARIES:

NameAgePositionsandOfficesHeldMarkC.Birk51SeniorVicePresident,CorporateSafety,PlanningandOperationsOversight(AmerenServices)BirkjoinedAmerenMissouriin1986.In2005,Birkwaselectedvicepresident,poweroperations,ofAmerenMissouri.In2012,Birkwaselectedseniorvicepresident,corporateplanning,ofAmerenServices.In2014,hewasalsoelectedseniorvice president,oversight,ofAmerenServices,andin2015,hewaselectedseniorvicepresident,corporatesafety,planningand operationsoversight.MaureenA.Borkowski58ChairmanandPresident(ATXI)BorkowskijoinedAmerenMissouriin1981.Sheleftthecompanyin2000andrejoinedAmerenin2005asvicepresident, transmission,ofAmerenServices.In2011,BorkowskiwaselectedchairmanandpresidentofATXI.In2011,shewasalso electedseniorvicepresident,transmission,ofAmerenServices.DanielF.Cole62ChairmanandPresident(AmerenServices)ColejoinedAmerenMissouriin1976.HewaselectedseniorvicepresidentofAmerenMissouriandAmerenServicesin1999 andofAmerenIllinoisin2001.In2009,ColewaselectedchairmanandpresidentofAmerenServices;heremainedseniorvice presidentofAmerenMissouriandAmerenIllinois.ColewillretirefromallofhispositionseffectiveMarch1,2016.FadiM.Diya53SeniorVicePresidentandChiefNuclearOfficer(AmerenMissouri)DiyajoinedAmerenMissouriin2005.In2008,Diyawaselectedvicepresident,nuclearoperations,ofAmerenMissouri.In January2014,DiyawaselectedseniorvicepresidentandchiefnuclearofficerofAmerenMissouri.MaryP.Heger59SeniorVicePresidentandChiefInformationOfficer(AmerenServices)HegerjoinedAmerenMissouriin1976.In2009,Hegerwaselectedvicepresident,informationtechnology,ofAmeren Services,andin2012,shewasalsoelectedchiefinformationofficerofAmerenServices.In2015,Hegerwaselectedsenior vicepresidentandchiefinformationofficerofAmerenServices.MarkC.Lindgren48SeniorVicePresident,CorporateCommunicationsandChiefHumanResourcesOfficer(AmerenServices)LindgrenjoinedAmerenServicesin1998.In2009,Lindgrenwaselectedvicepresident,humanresources,ofAmerenServices,andin2012,hewasalsoelectedchiefhumanresourcesofficerofAmerenServices.In2015,Lindgrenwaselected seniorvicepresident,corporatecommunications,andchiefhumanresourcesofficerofAmerenServices.RichardJ.Mark60ChairmanandPresident(AmerenIllinois)MarkjoinedAmerenServicesin2002.Hewaselectedseniorvicepresident,customeroperations,ofAmerenMissouriin 2005.In2012,MarkrelinquishedhispositionatAmerenMissouriandwaselectedchairmanandpresidentofAmerenIllinois.MichaelL.Moehn46ChairmanandPresident(AmerenMissouri)MoehnjoinedAmerenServicesin2000.In2008,hewaselectedseniorvicepresident,corporateplanningandbusinessrisk management,ofAmerenServices.In2012,Moehnwaselectedseniorvicepresident,customeroperations,ofAmeren Missouri.InApril2014,MoehnwaselectedchairmanandpresidentofAmerenMissouri.Officersaregenerallyelectedorappointedannuallybytherespectiveboardofdirectorsofeachcompany,followingtheelectionofboardmembersattheannualmeetingsofshareholders.Nospecialarrangementorunderstandingexistsbetween anyoftheabove-namedexecutiveofficersandtheAmerenCompaniesnor,toourknowledge,withanyotherpersonor personspursuanttowhichanyexecutiveofficerwasselectedasanofficer.Therearenofamilyrelationshipsamongthe executiveofficersorbetweenanyexecutiveofficersandanydirectorsoftheAmerenCompanies.Alloftheabove-named executiveofficershavebeenemployedbyanAmerencompanyformorethanfiveyearsinexecutiveormanagementpositions.

28 PARTIIITEM5.MARKETFORREGISTRANTS'COMMONEQUITY,RELATEDSTOCKHOLDERMATTERS,ANDISSUERPURCHASEOFEQUITYSECURITIESAmeren'scommonstockislistedontheNYSE(tickersymbol:AEE).Amerencommonshareholdersofrecordtotaled52,277onJanuary29,2016.Thefollowingtablepresentsthepriceranges,closingprices,anddividendsdeclaredperAmerencommonshareforeachquarterduring2015and2014:HighLowCloseDividendsDeclared2015QuarterEnded:March31............................................................$46.81$40.51$42.20$0.41June30.............................................................43.0037.2637.680.41September30

........................................................43.8537.5542.270.41December31

.........................................................44.7141.3343.230.4252014QuarterEnded:March31............................................................$42.24$35.22$41.20$0.40June30.............................................................41.9237.6740.880.40September30

........................................................40.9636.6538.330.40December31

.........................................................48.1438.2546.130.41ThereisnotradingmarketforthecommonstockofAmerenMissouriandAmerenIllinois.AmerenholdsalloutstandingcommonstockofAmerenMissouriandAmerenIllinois.ThefollowingtablesetsforththequarterlycommonstockdividendpaymentsmadebyAmerenanditsregistrantsubsidiariesduring2015and2014:(Inmillions) 2015QuarterEnded 2014QuarterEndedRegistrantDecember31September30June30March31December31September30June30March31AmerenMissouri

.........$85$75$100$315$72 (a)$113$78$77AmerenIllinois

...........--------Ameren................104991009999979797(a)Additionally,duringthefourthquarterof2014,AmerenMissourireturnedcapitalof$215milliontoAmeren(parent).OnFebruary12,2016,theboardofdirectorsofAmerendeclaredaquarterlydividendonAmeren'scommonstockof42.5centspershare.ThecommonsharedividendispayableMarch31,2016,toshareholdersofrecordonMarch9,2016.ForadiscussionofrestrictionsontheAmerenCompanies'paymentofdividends,seeLiquidityandCapitalResourcesinManagement'sDiscussionandAnalysisofFinancialConditionandResultsofOperationsunderPartII,Item7,ofthisreport.PurchasesofEquitySecurities Period(a)Total NumberofShares(orUnits)Purchased (a)(b)AveragePricePaidperShare(orUnit)(c)TotalNumberofShares(orUnits)PurchasedasPartofPubliclyAnnouncedPlansorPrograms(d)MaximumNumber(orApproximateDollarValue)ofShares(orUnits)thatMayYetBePurchasedUnderthePlansor ProgramsOctober1-October31,2015...................-$---November1-November30,2015

................2,27743.80--December1-December31,2015................----

Total.......................................2,277$43.80--(a)ThesesharesofAmerencommonstockwerepurchasedinopen-markettransactionstofundAmeren'sobligationsforitsdirectors'stockcompensationawards,whichweregrantedunderthe2014IncentivePlan.Amerendoesnothaveanypubliclyannouncedequitysecuritiespurchaseplansorprograms.AmerenMissouriandAmerenIllinoisdidnotpurchaseanyequitysecuritiesreportableunderItem703ofRegulationS-KduringtheperiodfromOctober1,2015,toDecember31,2015.

29 PerformanceGraphThefollowinggraphshowsAmeren'scumulativetotalshareholderreturnduringthefiveyearsendedDecember31,2015.ThegraphalsoshowsthecumulativetotalreturnsoftheS&P500IndexandtheEdisonElectricInstituteIndex(EEIIndex),whichcomprisesmostinvestor-ownedelectricutilitiesintheUnitedStates.Thecomparisonassumesthat$100wasinvested onDecember31,2010,inAmerencommonstockandineachoftheindicesshown,anditassumesthatallofthedividends werereinvested.

$100 2015 2014 2013 2012 2011 2010 AEE S&P 500 I nd ex EEI I nd ex$50$150$200

$250December31,201020112012201320142015Ameren(AEE).....................................$100.00$123.92$120.78$148.94$197.69$193.00S&P500Index

....................................100.00102.11118.45156.81178.28 180.74EEIIndex.........................................100.00119.99122.50138.43178.46 171.50Amerenmanagementcautionsthatthestockpriceperformanceshowninthegraphaboveshouldnotbeconsideredindicativeofpotentialfuturestockpriceperformance.

30 ITEM6.SELECTEDFINANCIALDATAFortheyearsendedDecember31,(Inmillions,exceptpershareamounts)20152014201320122011 Ameren (a):Operatingrevenues

..........................................$6,098$6,053$5,838$5,781$6,148Operatingincome (b)..........................................

1,2591,2541,1841,1881,033Incomefromcontinuingoperations

..............................

585593518522437Income(loss)fromdiscontinuedoperations,netoftaxes (c)...........

51(1)(223)(1,496)89Netincome(loss)attributabletoAmerencommonshareholders

.......630586289(974)519Commonstockdividends

.....................................

402390388382375Continuingoperationsearningspershare-basic

...................

2.392.422.112.131.79Continuingoperationsearningspershare-diluted

.................

2.382.402.102.131.79Commonstockdividendspershare

.............................

1.6551.611.601.601.555AsofDecember31:Totalassets (d)(e).............................................$23,640$22,289$20,907$22,022$23,667Long-termdebt,excludingcurrentmaturities (f).....................

6,8806,0855,4755,7655,817TotalAmerenCorporationshareholders'equity

.....................

6,9466,7136,5446,6167,919AmerenMissouri:Operatingrevenues

..........................................$3,609$3,553$3,541$3,272$3,383Operatingincome (b)..........................................

742785803845609Netincomeavailabletocommonshareholder

......................

352390395416287Dividendstoparent

..........................................

575340460400403AsofDecember31:Totalassets (e)...............................................$13,851$13,474$12,867$12,998$12,731Long-termdebt,excludingcurrentmaturities (f).....................

3,8443,8613,6313,7823,754Totalshareholders'equity

.....................................

4,0824,0523,9934,0544,037AmerenIllinois:Operatingrevenues

..........................................$2,466$2,498$2,311$2,525$2,787Operatingincome

...........................................

466450415377458Netincomeavailabletocommonshareholder

......................

214201160141193Dividendstoparent

..........................................

--110189327AsofDecember31:Totalassets (e)...............................................$8,903$8,204$7,397$7,186$7,144Long-termdebt,excludingcurrentmaturities (f).....................

2,3422,2241,8441,5661,646Totalshareholders'equity

.....................................

2,8972,6612,4482,4012,452(a)IncludesamountsforAmerenregistrantandnonregistrantsubsidiariesandintercompanyeliminations.(b)Includesa$69millionprovisionrecordedin2015forallofthepreviouslycapitalizedCOLcostsrelatingtothesecondnuclearunitatitsexistingCallawayenergycenter.AlsoincludesregulatorydisallowanceassociatedwiththeTaumSaukbreachof$89millionin2011.(c)SeeNote16-DivestitureTransactionsandDiscontinuedOperationsunderPartII,Item8,ofthisreportforadditionalinformation.

(d)Includestotalassetsfromdiscontinuedoperationsof$14million,$15million,$165million,$1,611million,and$3,721millionatDecember31,2015,2014,2013,2012,and2011,respectively.(e)Reflectstheadoptionofthenewauthoritativeaccountingguidanceforthepresentationofdebtissuancecostsanddeferredincometaxes.SeeNote1-SummaryofSignificantAccountingPoliciesunderPartII,Item8ofthisreportforadditionalinformation.(f)Reflectstheadoptionofthenewauthoritativeaccountingguidanceforthepresentationofdebtissuancecosts.SeeNote1-SummaryofSignificantAccountingPoliciesunderPartII,Item8ofthisreportforadditionalinformation.ITEM7.MANAGEMENT'SDISCUSSIONANDANALYSISOFFINANCIALCONDITIONANDRESULTSOFOPERATIONSAmeren,headquarteredinSt.Louis,Missouri,isapublicutilityholdingcompanyunderPUHCA2005.Ameren'sprimaryassetsareitsequityinterestsinits subsidiaries,includingAmerenMissouriandAmeren Illinois.Ameren'ssubsidiariesareseparate,independent legalentitieswithseparatebusinesses,assets,and liabilities.DividendsonAmeren'scommonstockandthe paymentofexpensesbyAmerendependondistributions madetoitbyitssubsidiaries.BelowisasummarydescriptionofAmerenMissouriandAmerenIllinois.AmoredetaileddescriptioncanbefoundinNote1-SummaryofSignificantAccounting PoliciesunderPartII,Item8,ofthisreport.

AmerenMissourioperatesarate-regulatedelectricgeneration,transmission,anddistributionbusinessand arate-regulatednaturalgastransmissionand distributionbusinessinMissouri.

AmerenIllinoisoperatesrate-regulatedelectricand naturalgastransmissionanddistributionbusinessesin

Illinois.Amerenhasvariousothersubsidiariesthatconductactivitiessuchastheprovisionofsharedservices.Ameren 31 alsohasasubsidiary,ATXI,thatoperatesaFERCrate-regulatedelectrictransmissionbusiness.ATXIisdeveloping MISO-approvedelectrictransmissionprojects,includingthe IllinoisRivers,SpoonRiver,andMarkTwainprojects.

Amerenisalsopursuingprojectstoimproveelectric transmissionsystemreliabilitywithinAmerenMissouri's andAmerenIllinois'serviceterritoriesaswellas competitiveelectrictransmissioninvestmentopportunities outsideoftheseterritories,includinginvestmentsoutsideof

MISO.Unlessotherwisestated,thefollowingsectionsofManagement'sDiscussionandAnalysisofFinancial ConditionandResultsofOperationsexcludediscontinued operationsforallperiodspresented.SeeNote16-DivestitureTransactionsandDiscontinuedOperationsunder PartII,Item8,ofthisreportforadditionalinformation regardingthatpresentation.Ameren'sfinancialstatementsarepreparedonaconsolidatedbasis,andthereforeincludetheaccountsofits majority-ownedsubsidiaries.AmerenMissouriandAmeren Illinoishavenosubsidiaries,andthereforetheirfinancial statementsarenotpreparedonaconsolidatedbasis.All intercompanytransactionshavebeeneliminated.Alltabular dollaramountsareinmillions,unlessotherwiseindicated.Inadditiontopresentingresultsofoperationsandearningsamountsintotal,wepresentcertaininformationin centspershare.Theseamountsreflectfactorsthatdirectly affectAmeren'searnings.Webelievethispershare informationhelpsreaderstounderstandtheimpactofthese factorsonAmeren'searningspershare.Allreferencesin thisreporttoearningspersharearebasedonaverage dilutedcommonsharesoutstanding.

OVERVIEWAmeren'sstrategicplanincludesinvestinginandoperatingitsutilitiesinamannerconsistentwithexistingregulatoryframeworks,enhancingthoseframeworksand advocatingforresponsibleenergypolicies,aswellas creatingandcapitalizingonopportunitiesforinvestmentfor thebenefitofitscustomersandshareholders.In2015, Amerencontinuedtosuccessfullyexecuteitsstrategyto investinandtogrowitsutilitiesthroughinvestmentinrate-regulatedinfrastructurewhileremainingfocusedon operationalimprovementanddisciplinedcostmanagement.

Amerencontinuestoallocatesignificantamountsofcapital tothosebusinessesthataresupportedbyconstructive regulatoryframeworks,investing$1.3billioninitsFERC-regulatedelectrictransmissionandIllinoiselectricand naturalgasdeliverybusinesses.Reflectingconfidencein Ameren'slong-termstrategyandoutlook,Ameren'sboard ofdirectorsincreasedthequarterlydividendrateinOctober

2015.WithrespecttotheFERC-regulatedelectrictransmissionbusinesses,therearecurrentlytwocomplaint casesfiledwiththeFERCseekingareductionintheallowed basereturnoncommonequityundertheMISOtariff.In December2015,anadministrativelawjudgeissuedaninitialdecisionintheNovember2013complaintcasethat wouldlowertheallowedbasereturnoncommonequityto 10.32%.TheFERCisexpectedtoissueafinalorderonthe November2013complaintcasebyOctober2016.Aninitial decisionfromanadministrativelawjudgeintheFebruary 2015complaintcase,whichwillsubsequentlyrequireFERC approval,isexpectedtobeissuedbyJune30,2016.In January2015,aFERC-approvedincentiveadderofupto 50basispointsontheallowedbasereturnoncommon equityforourparticipationinanRTObecameeffective.

BeginningwithitsJanuary2015effectivedate,theincentive adderwillreduceanyrefundtocustomersrelatingtoa reductionoftheallowedbasereturnoncommonequity fromthecomplaintcases.InDecember2015,theICCissuedanorderinAmerenIllinois'annualupdatefilingapprovinga$106million increaseinAmerenIllinois'electricdeliveryservicerevenue requirementbeginninginJanuary2016.Additionally,in December2015,theICCissuedarateorderthatapproved anincreaseinrevenuesforAmerenIllinois'naturalgas deliveryserviceof$45million.Therateorderalsoapproved theVBAforresidentialandsmallnonresidentialcustomers beginningin2016.AmerenisevaluatingtheCleanPowerPlan'spotentialimpactstoitsoperations,includingthoserelatedtoelectric systemreliability,anditslevelofinvestmentincustomer energyefficiencyprograms,renewableenergy,andother formsofgenerationinvestment.InFebruary2016,the UnitedStatesSupremeCourtstayedtheCleanPowerPlan andallimplementationrequirementsuntilsuchtimeas legalappealsareconcluded.TheDistrictofColumbiaCircuit CourtofAppealshasscheduledhearingsforJune2016on thelegalityoftherule.AdecisionbytheDistrictof ColumbiaCircuitCourtofAppealsisexpectedtobeissued laterthisyearandadditionalappealsbeforetheUnited StatesSupremeCourtarelikely.Appealsarenotexpected toconcludepriorto2018.Amerenwillcontinuetoadvocate forresponsibleenergypoliciesrelatedtotheCleanPower Planwhileworkingwithkeystakeholderstoaddress importantissuesassociatedwiththeMissouriandIllinois stateimplementationplansshouldtheCleanPowerPlan ultimatelybeupheld.AmerenMissouricontinuestoseeklegislativesolutionstoaddressregulatorylagandtosupport investmentinitsutilityinfrastructureforthebenefitofits customers,includingthroughitsadvocacyforalegislative solutiontosupportNoranda'soperations.OnJanuary8, 2016,AmerenMissouri'slargestcustomer,Noranda, announcedthatproductionhadbeenidledattwoofits threepotlinesatthesmelterfollowinganelectricsupply circuitfailureonassetsnotownedbyAmerenMissouri.On February8,2016,Norandafiledvoluntarypetitionsfora court-supervisedrestructuringprocessunderChapter11of theUnitedStatesBankruptcyCode.Inthefiling,Noranda reaffirmedthattheremainingpotlinewillcontinueto operateatthesmelteruntilMarch2016,atwhichtime operationofthelinewillbecurtailed.Norandastatedit wouldmaintaintheflexibilitytorestartoperationsatthe 32 smeltershouldconditionsallow.InJanuary2016,AmerenMissourifiledanoticewiththeMoPSCthatwouldenable AmerenMissouritofileanelectricratecaseafter60days.

AmerenMissouriexpectstofileanelectricratecasein 2016andexpectstheresultingnewratestoreflect Noranda'sactualsalesvolumeswhichwouldprospectively eliminatetheimpactofthecurrentrevenueshortfall.

AmerenMissourimayseekrecoveryoflostrevenuesina filingwiththeMoPSCforcertaincostsincurredbutnot contemporaneouslyrecoveredasaresultofNoranda's reducedoperations.AmerenMissouriwillcontinueto monitorNoranda'ssalesvolumesandtoevaluateits regulatoryandlegislativeoptionsthatmightmitigate adversefinancialimpacts.InFebruary2016,theMoPSCissuedanorderapprovingAmerenMissouri'sMarch2016toFebruary2019 MEEIAplanwhichincludedaportfolioofcustomerenergy efficiencyprogramsalongwitharidertocollectthe programcosts,thethroughputdisincentive,anda performanceincentivefromcustomers.Theplanprovides AmerenMissourianopportunitytoearnadditionalrevenues byachievingcertaincustomerenergyefficiencygoals, including$27millionif100%ofthegoalsareachieved duringthethree-yearperiod,withthepotentialtoearnmore ifAmerenMissouri'senergysavingsexceedthosegoals.

EarningsNetincomeattributabletoAmerencommonshareholdersfromcontinuingoperationswas$579million,or$2.38perdilutedshare,for2015,and$587million,or

$2.40perdilutedshare,for2014.Theseearningswere unfavorablyaffectedin2015,comparedwith2014,bya provisionrecognizedasaresultofAmerenMissouri's discontinuedeffortstolicenseandbuildasecondnuclear unitatitsexistingCallawayenergycentersiteaswellas decreasedelectricandnaturalgassalesvolumesprimarily duetowarmerwintertemperatures.Additionally,increased netfinancingcostsatAmerenMissouriandincreased depreciationandamortizationexpensesforthose businessesnotoperatingunderformularatesunfavorably affectedearnings.Theabsencein2015ofarecoveryof certainpreviouslydisalloweddebtpremiumcostsperthe ICC'sDecember2014orderalsonegativelyaffected earnings.ThedecreaseinAmeren'snetincomefrom continuingoperationswaspartiallyoffsetbyincreased AmerenIllinoisandATXIelectrictransmissionserviceand AmerenIllinoiselectricdeliveryserviceearnings,reflecting Ameren'sstrategytoallocatesignificantcapitaltothose businesses.Earningswerepositivelyaffectedbythe absenceofaCallawayenergycenterscheduledrefueling andmaintenanceoutageatAmerenMissouriaswellas increasedAmerenIllinoisearningsresultingfromaJanuary 2015ICCorderregardingAmerenIllinois'cumulativepower usagecostanditspurchasedpowerridermechanism.

Decreasedoperationsandmaintenanceexpensesprimarily atAmerenMissouriandatnonregistrantsubsidiariesand decreasedinterestexpenseatAmeren(parent)also favorablyaffectedearnings.

LiquidityCashgeneratedbyoperatingactivitiesassociatedwithcontinuingoperationsandbyissuancesoflong-termdebt wereusedtofundcapitalexpenditures,repayshort-term debt,andpaydividendstocommonshareholders.At December31,2015,Ameren,onaconsolidatedbasis,had availableliquidity,intheformofcashonhandandamounts availableunderexistingcreditagreements,of$2.1billion.CapitalSpendingIn2015,Amerenmadesignificantinvestmentsinitsutilities.Itexpectsthattrendtocontinueintothefuture.From2016through2020,Ameren'scumulativecapital spendingisprojectedtorangebetween$10.6billionand

$11.5billion.Theprojectedspendingincludes$4.1billion,

$6.0billion,and$1.0billionforAmerenMissouri,Ameren Illinois,andATXI,respectively.InDecember2015,afederal taxlawwasenactedthatauthorizedthecontinueduseof bonusdeprecationthatallowsforanaccelerationof deductionsfortaxpurposes.Bonusdepreciationis expectedtoincreasecashflowthroughatleast2020.

Amerenexpectstousethisincrementalcashflowtomake investmentsinutilityinfrastructureforthebenefitofits

customers.RESULTSOFOPERATIONSOurresultsofoperationsandfinancialpositionareaffectedbymanyfactors.Weather,economicconditions,energyefficiencyinvestmentsbyourcustomersandus,and theactionsofkeycustomerscansignificantlyaffectthe demandforourservices.Ourresultsarealsoaffectedby seasonalfluctuationsinwinterheatingandsummercooling demands.Wearealsoaffectedbynuclearrefuelingand otherenergycentermaintenanceoutagesatAmeren Missouri.Additionally,fluctuationsininterestratesand conditionsinthecapitalandcreditmarketsaffectourcost ofborrowingandourpensionandpostretirementbenefits costs.AlmostallofAmeren'srevenuesaresubjecttostate orfederalregulation.Thisregulationhasamaterialimpact onthepriceswechargeforourservices.Ourresultsof operations,financialposition,andliquidityareaffectedby ourabilitytoalignouroverallspending,bothoperatingand capital,withregulatoryframeworksestablishedbyour

regulators.AmerenMissouriprincipallyusescoal,nuclearfuel,andnaturalgasforfuelinitselectricoperationsand purchasesnaturalgasforitscustomers.AmerenIllinois purchasespowerandnaturalgasforitscustomers.The pricesforthesecommoditiescanfluctuatesignificantly becauseoftheglobaleconomicandpoliticalenvironment, weather,supplyanddemand,andmanyotherfactors.We havenaturalgascostrecoverymechanismsforourIllinois andMissourinaturalgasdeliveryservicebusinesses,a purchasedpowercostrecoverymechanismforAmeren Illinois'electricdeliveryservicebusiness,andaFACfor AmerenMissouri'selectricutilitybusiness.

33 AmerenIllinois'electricdeliveryserviceutilitybusiness,pursuanttotheIEIMA,conductsanannualreconciliationoftherevenuerequirementnecessaryto reflecttheactualcostsincurredinagivenyearwiththe revenuerequirementincludedincustomerratesforthat year,withrecoveriesfrom,orrefundsto,customersmade inasubsequentyear.IncludedinAmerenIllinois'revenue requirementreconciliationisaformulaforthereturnon equity,whichisequaltotheaverageofthemonthlyyields of30-yearUnitedStatesTreasurybondsplus580basis points.Therefore,AmerenIllinois'annualreturnonequityis directlycorrelatedtoyieldsonUnitedStatesTreasury bonds.AmerenIllinoisandATXIuseacompany-specific, forward-lookingrateformulaframeworkinsettingtheir transmissionrates.Theseforward-lookingratesare updatedeachJanuarywithforecastedinformation.A reconciliationduringtheyear,whichadjustsfortheactual revenuerequirementandactualsalesvolumes,isusedto adjustbillingratesinasubsequentyear.AmerenIllinois'andATXI'selectrictransmissionservicebusinessesandAmerenIllinois'electricdelivery servicebusinessoperateunderformularatemaking, designedtoprovidefortherecoveryofactualcostsof servicethatareprudentlyincurredaswellasareturnon equity.Whilerate-regulated,AmerenIllinois'naturalgas businessandAmerenMissouridonotoperateunder formularatemaking.Ameren(parent)isnotrate-regulated.Weemployvariousriskmanagementstrategiestoreduceourexposuretocommodityriskandotherrisks inherentinourbusiness.ThereliabilityofAmerenMissouri's energycentersandourtransmissionanddistribution systemsandthelevelofpurchasedpowercosts,operations andmaintenancecosts,andcapitalinvestmentarekey factorsthatweseektomanageinordertooptimizeour resultsofoperations,financialposition,andliquidity.EarningsSummaryThefollowingtablepresentsasummaryofAmeren'searningsfortheyearsendedDecember31,2015,2014,and

2013:201520142013NetincomeattributabletoAmerencommonshareholders

.............$630$586$289Earningspercommonshare-diluted...

2.592.401.18NetincomeattributabletoAmerencommonshareholders-continuing operations

.......................

579587512Earningspercommonshare-diluted-continuingoperations

..............

2.382.402.102015versus2014NetincomeattributabletoAmerencommonshareholdersfromcontinuingoperationsin2015decreased$8million,or$0.02perdilutedshare,from2014.The decreasewasduetoa$38milliondecreaseinnetincome fromtheAmerenMissourisegment,partiallyoffsetbya

$13millionincreaseinnetincomefromtheAmerenIllinoissegment.Netincomefromnonregistrantsubsidiariesand Ameren(parent)in2015was$13millioncomparedwitha

$4millionnetlossin2014,whichincludednetincomefrom ATXIof$31millionand$13million,respectively.In2015,netincomeattributabletoAmerencommonshareholdersfromdiscontinuedoperationswasfavorably affectedbytherecognitionofataxbenefitresultingfrom theremovalofareserveforunrecognizedtaxbenefitsof

$53millionrecordedin2013relatedtothedivestitureof NewAER,basedonthecompletionoftheIRSauditof Ameren's2013taxyear.Comparedwith2014,2015earningspersharefromcontinuingoperationswereunfavorablyaffectedby:

aprovisionrecognizedinthesecondquarterof2015asaresultofAmerenMissouri'sdiscontinuedeffortsto licenseandbuildasecondnuclearunitatitsexisting Callawayenergycentersite(18centspershare);

decreasedelectricandnaturalgassalesvolumes primarilyduetowarmerwintertemperaturesin2015 (estimatedat6centspershare);

increasednetfinancingcostsatAmerenMissouri, primarilyduetoareductioninallowanceforfundsused duringconstructionasmultiplesignificantelectriccapital projectswerecompletedin2014(6centspershare);

increaseddepreciationandamortizationexpensesfor thosebusinessesnotoperatingunderformularates, primarilyresultingfromelectriccapitaladditions completedin2014atAmerenMissouri,whichwerenot reflectedincustomerratesuntilMay30,2015,and amortizationofnaturalgas-relatedinvestmentsat AmerenIllinois(5centspershare);and theabsencein2015ofarecoveryofcertainpreviously disalloweddebtpremiumcostspertheICC'sDecember 2014order(3centspershare).Comparedwith2014,2015earningspersharefromcontinuingoperationswerefavorablyaffectedby:

increasedAmerenIllinoisandATXIelectrictransmissionserviceandAmerenIllinoiselectricdeliveryserviceearningsunderformularatemaking,primarilydueto additionalratebaseinvestmentaswellasinterest earnedontherevenuerequirementreconciliation adjustmentregulatoryassets(20centspershare).

Theseearningswerereducedbytherecognitionofa liabilityforapotentialrefundtocustomersbasedonthe pendingFERCcomplaintcasesregardingtheallowed basereturnoncommonequityaswellasalowerreturn onequityrelatedtoAmerenIllinoiselectricdelivery serviceinvestmentsduetoareductioninthe30-year UnitedStatesTreasurybondyields(5centspershare);

theabsenceofaCallawayenergycenterscheduled refuelingandmaintenanceoutagein2015,whichlast occurredinthefourthquarterof2014,partiallyoffset bypreparationcostsincurredin2015forthe2016 scheduledrefuelingoutage(7centspershare);

increasedAmerenIllinoisearningsresultingfroma January2015ICCorderregardingAmerenIllinois' cumulativepowerusagecostanditspurchasedpower ridermechanism(4centspershare);

34 excludingthescheduledrefuelingandmaintenanceoutage,MEEIAprogramcosts,andexpenseswith correspondingincreasesinelectricrevenuesresulting fromtheApril2015MoPSCelectricrateorder, decreasedotheroperationsandmaintenanceexpenses atAmerenMissouriprimarilybecauseofdecreased energycentercostsandatnonregistrantsubsidiaries (4centspershare);and decreasedinterestexpenseatAmeren(parent),

primarilyduetothematurityofhigher-costdebtin 2014beingreplacedwithlower-costdebt(3centsper

share).Thecentspershareinformationpresentedaboveisbasedonthedilutedaveragesharesoutstandingin2014.2014versus2013NetincomeattributabletoAmerencommonshareholdersfromcontinuingoperationsin2014increased$75million,or$0.30perdilutedshare,from2013.The increasewasduetoa$41millionincreaseinnetincome fromtheAmerenIllinoissegmentanda$39million decreaseinnetlossfromAmeren(parent)and nonregistrantsubsidiaries,whichincludedanincreasein ATXI'snetincomeof$6million.Theincreasewaspartially offsetbya$5milliondecreaseinnetincomefromthe AmerenMissourisegment.Comparedwith2013,2014earningspersharefromcontinuingoperationswerefavorablyaffectedby:

highernaturalgasratesatAmerenIllinoispursuanttoaDecember2013order(8centspershare);

decreasedinterestexpense,excludingtheeffectsofthe ICC'sDecember2014orderdiscussedbelow,primarily duetothematurityofhigher-costdebtreplacedwith issuancesoflower-costdebt(8centspershare);

theabsencein2014ofareductioninAmerenMissouri revenuesresultingfromaJuly2013MoPSCorderthat requiredarefundtocustomersassociatedwithcertain long-termpartialrequirementssalesrecognizedfrom October1,2009,toMay31,2011(7centspershare);

theICC'sDecember2014orderallowingpartial recoveryofcertainpreviouslydisalloweddebtpremium coststhatwerechargedtoearningsin2013(7cents pershare);

anincreaseinAmerenIllinois'andATXI'selectric transmissionearningsunderformularatemakingdueto additionalratebaseinvestment,partiallyoffsetbythe recognitionofaliabilityforapotentialrefundto customersbasedonthependingFERCNovember2013 complaintcaseregardingtheallowedbasereturnon commonequity(6centspershare);

anincreaseinAmerenIllinois'electricdeliveryservice earningsunderformularatemakingpursuanttothe IEIMAduetoincreasedratebaseinvestment(estimated at5centspershare);

increasednetsharedbenefitsrealizedundertheMEEIA atAmerenMissouri(4centspershare),whichwere partiallyoffsetbylowerrevenuesresultingfrom reduceddemandduetocustomerenergyefficiency programs;and increasedelectricandnaturalgassalesvolumes primarilyresultingfromcolderwintertemperaturesin early2014andwarmerearlysummertemperatures (estimatedat1centpershare).Comparedwith2013,2014earningspersharefromcontinuingoperationswereunfavorablyaffectedby:

increaseddepreciationandamortizationexpenses,primarilyresultingfromelectricdistributioncapital additionsatAmerenMissouri(5centspershare);

anincreaseintheeffectivetaxrate(4centspershare);

andincreasedotheroperationsandmaintenanceexpenses forAmerenMissouriandforAmerenIllinois'natural gasbusiness,primarilyduetoincreasedlaborand litigationcosts,offsetinpartbydecreasedcostsat Ameren(parent),primarilyresultingfromthe substantialeliminationofcostspreviouslyincurredin supportofthedivestedmerchantgenerationbusiness (3centspershare).Thecentspershareinformationpresentedaboveisbasedonthedilutedaveragesharesoutstandingin2013.ForadditionaldetailsregardingtheAmerenCompanies'resultsofoperations,includingexplanationsof Margins,OtherOperationsandMaintenanceExpenses, ProvisionforCallawayConstructionandOperatingLicense, DepreciationandAmortization,TaxesOtherThanIncome Taxes,OtherIncomeandExpenses,InterestCharges, IncomeTaxes,andIncome(Loss)fromDiscontinued Operations,NetofTaxes,seethemajorheadingsbelow.

35 BelowisatableofincomestatementcomponentsbysegmentfortheyearsendedDecember31,2015,2014,and2013:

2015 Ameren Missouri Ameren IllinoisOther/IntersegmentEliminationsTotalElectricmargins

...........................................................$2,481$1,263$44$3,788Naturalgasmargins

.......................................................80425(2)503Otherrevenues

...........................................................2-(2)-Otheroperationsandmaintenance

............................................(925)(797)28(1,694)ProvisionforCallawayconstructionandoperatinglicense

..........................(69)--(69)Depreciationandamortization

................................................(492)(295)(9)(796)Taxesotherthanincometaxes

...............................................(335)(130)(8)(473)Otherincomeand(expenses)

................................................419(6)44Interestcharges

...........................................................(219)(131)(5)(355)Incometaxes

.............................................................(209)(127)(27)(363)Incomefromcontinuingoperations

...........................................35521713585Incomefromdiscontinuedoperations,netoftaxes

................................--5151Netincome..............................................................35521764636Noncontrollinginterests-preferreddividends

...................................(3)(3)-(6)NetincomeattributabletoAmerencommonshareholders

..........................$352$214$64$630 2014Electricmargins...........................................................$2,436$1,179$11$3,626Naturalgasmargins.......................................................82443-525Otherrevenues...........................................................1-(1)-Otheroperationsandmaintenance

............................................(939)(771)26(1,684)Depreciationandamortization

................................................(473)(263)(9)(745)Taxesotherthanincometaxes

...............................................(322)(138)(8)(468)Otherincome.............................................................489-57Interestcharges

...........................................................(211)(112)(18)(341)Incometaxes

.............................................................(229)(143)(5)(377)Income(loss)fromcontinuingoperations......................................393204(4)593Lossfromdiscontinuedoperations,netoftaxes..................................--(1)(1)Netincome(loss).........................................................393204(5)592Noncontrollinginterests-preferreddividends...................................(3)(3)-(6)Netincome(loss)attributabletoAmerencommonshareholders.....................$390$201$(5)$586 2013Electricmargins...........................................................$2,401$1,081$(3)$3,479Naturalgasmargins.......................................................83399(2)480Otherrevenues...........................................................13(4)-Otheroperationsandmaintenance

............................................(909)(693)(9)(1,611)Depreciationandamortization

................................................(454)(243)(9)(706)Taxesotherthanincometaxes

...............................................(319)(132)(7)

(458)Otherincomeand(expenses)................................................471(5)43Interestcharges

...........................................................(210)(143)(45)(398)Income(taxes)benefit

......................................................(242)(110)41(311)Income(loss)fromcontinuingoperations......................................398163(43)518Lossfromdiscontinuedoperations,netoftaxes..................................--(223)(223)Netincome(loss).........................................................398163(266)295Noncontrollinginterests-preferreddividends...................................(3)(3)-(6)Netincome(loss)attributabletoAmerencommonshareholders.....................$395$160$(266)$289 36 MarginsThefollowingtablepresentsthefavorable(unfavorable)variationsbysegmentforelectricandnaturalgasmarginsin2015comparedwith2014,aswellas2014comparedwith2013.Electricmarginsaredefinedaselectricrevenueslessfuelandpurchasedpowercosts.Naturalgasmarginsaredefinedasgasrevenueslessgaspurchasedforresale.Weconsider electricandnaturalgasmarginsusefulmeasurestoanalyzethechangeinprofitabilityofourelectricandnaturalgas operationsbetweenperiods.Wehaveincludedtheanalysisbelowasacomplementtothefinancialinformationweprovidein accordancewithGAAP.However,thesemarginsmaynotbeapresentationdefinedunderGAAP,andtheymaynotbe comparabletoothercompanies'presentationsormoreusefulthantheGAAPinformationweprovideelsewhereinthisreport.2015versus2014 Ameren Missouri AmerenIllinoisOther (a)AmerenElectricrevenuechange:Effectofweather(estimate)(b)........................................................$(20)$(10)$-$(30)Baserates(estimate)...............................................................8234-116Salesvolume(excludingtheestimatedeffectofweather)

...................................(36)(1)-(37)Off-systemsalesandtransmissionservicesrevenues......................................3--3MEEIAnetsharedbenefits...........................................................33--33Transmissionservicesrevenues (c).....................................................1293767Purchasedpowerriderorder.........................................................-15-15 Other...........................................................................2(7)(13)(18)Costrecoverymechanisms-offsetinfuelandpurchasedpower (d):Powersupplycosts..............................................................-81-81Transmissionservicesrecoverymechanism...........................................-10-10RecoveryofFACunder-recovery....................................................(5)--(5)Othercostrecoverymechanisms (e):Baddebt,energyefficiencyprograms,andenvironmentalremediationcostriders..............-10-10Grossreceiptstax...............................................................6--6MEEIAprogramcosts............................................................16--16Totalelectricrevenuechange...........................................................$82$161$24$267Fuelandpurchasedpowerchange:Energycosts.....................................................................$21$-$-$21Effectofweather(estimate)(b)........................................................1010-20Effectofhighernetenergycostsincludedinbaserates

.....................................(65)--(65)FACexclusionoftransmissionservicesexpenses (c)........................................(7)--(7)

Other...........................................................................(1)4912Costrecoverymechanisms-offsetinelectricrevenue (d):Powersupplycosts..............................................................-(81)-(81)Transmissionservicesrecoverymechanism...........................................-(10)-(10)RecoveryofFACunder-recovery....................................................5--5Totalfuelandpurchasedpowerchange...................................................$(37)$(77)$9$(105)Netchangeinelectricmargins

.........................................................$45$84$33$162Naturalgasrevenuechange:

...........................................................Effectofweather(estimate)(b)........................................................$(17)$(72)$-$(89)

Other...........................................................................21(2)1Costrecoverymechanism-offsetingaspurchasedforresale (d):Purchasedgascosts

.............................................................(11)(113)-(124)Othercostrecoverymechanisms (e):Baddebt,energyefficiencyprograms,andenvironmentalremediationcostriders..............-(2)-(2)Grossreceiptstax...............................................................(1)(7)-(8)Totalnaturalgasrevenuechange........................................................$(27)$(193)$(2)$(222)Gaspurchasedforresalechange:Effectofweather(estimate)(b)........................................................$14$62$-$76Costrecoverymechanism-offsetinnaturalgasrevenue (d):Purchasedgascosts.............................................................11113-124Totalgaspurchasedforresalechange....................................................$25$175$-$200Netchangeinnaturalgasmargins

......................................................$(2)$(18)$(2)$(22) 37 2014versus2013 Ameren Missouri AmerenIllinoisOther (a)AmerenElectricrevenuechange:Effectofweather(estimate)(b)........................................................$8$(5)$-$3Baserates(estimate)...............................................................-56-56Salesvolume(excludingtheestimatedeffectofweather)

...................................(22)3-(19)Off-systemsalesandtransmissionservicesrevenues

......................................(12)--(12)FACprudencerevieworderin2013....................................................25--25MEEIAnetsharedbenefits...........................................................15--15Transmissionservicesrevenues......................................................-101424 Other...........................................................................26(3)5Costrecoverymechanisms-offsetinfuelandpurchasedpower (d):Powersupplycosts..............................................................-(38)-(38)Transmissionservicesrecoverymechanism...........................................-4-4RecoveryofFACunder-recovery

....................................................(14)--(14)Othercostrecoverymechanisms (e):Baddebt,energyefficiencyprograms,andenvironmentalremediationcostriders..............-25-25MEEIAprogramcosts............................................................7--7Totalelectricrevenuechange...........................................................$9$61$11$81Fuelandpurchasedpowerchange:Energycosts.....................................................................$18$-$-$18Effectofweather(estimate)(b)........................................................(5)--(5)

Other...........................................................................(1)335Costrecoverymechanisms-offsetinelectricrevenue (d):Powersupplycosts..............................................................-38-38Transmissionservicesrecoverymechanism...........................................-(4)-(4)RecoveryofFACunder-recovery....................................................14--14Totalfuelandpurchasedpowerchange...................................................$26$37$3$66Netchangeinelectricmargins

.........................................................$35$98$14$147Naturalgasrevenuechange:Effectofweather(estimate)(b)........................................................$6$32$-$38Baserates(estimate)...............................................................-32-32 Other...........................................................................(2)121Costrecoverymechanism-offsetingaspurchasedforresale (d):Purchasedgascosts.............................................................(1)57-56Othercostrecoverymechanisms (e):Baddebt,energyefficiencyprograms,andenvironmentalremediationcostriders..............-4-4Grossreceiptstax...............................................................-3-3Totalnaturalgasrevenuechange........................................................$3$129$2$134Gaspurchasedforresalechange:Effectofweather(estimate)(b)........................................................$(5)$(28)$-$(33)Costrecoverymechanism-offsetinnaturalgasrevenue (d):Purchasedgascosts.............................................................1(57)-(56)Totalgaspurchasedforresalechange....................................................$(4)$(85)$-$(89)Netchangeinnaturalgasmargins

......................................................$(1)$44$2$45(a)PrimarilyincludesamountsforATXIandintercompanyeliminations.(b)Representstheestimatedvariationresultingprimarilyfromchangesincoolingandheatingdegree-daysonelectricandnaturalgasdemandcomparedwiththeprioryear;thisvariationisbasedontemperaturereadingsfromtheNationalOceanicandAtmosphericAdministration weatherstationsatlocalairportsinourserviceterritories.(c)AmerenMissouriamountsaresubsequenttoMay30,2015,duetotheexclusionoftransmissionrevenuesandsubstantiallyalltransmissionchargesfromtheFACasaresultoftheApril2015MoPSCelectricrateorder.(d)ElectricandnaturalgasrevenuechangesareoffsetbycorrespondingchangesinFuel,Purchasedpower,andGaspurchasedforresale,resultinginnochangetoelectricandgasmargins.(e)SeeOtherOperationsandMaintenanceExpensesorTaxesOtherThanIncomeTaxesinthissectionfortherelatedoffsettingincreaseordecreasetoexpense.Theseitemshavenooverallimpactonearnings.2015versus2014AmerenCorporationAmeren'selectricmarginsincreased$162million,or4%,in2015comparedwith2014.Ameren'snaturalgasmarginsdecreased$22million,or4%,in2015comparedwith2014.TheseresultswereprimarilydrivenbyAmeren MissouriandAmerenIllinoisresults,asdiscussedbelow.

Ameren'selectricmarginsalsoreflecttheresultsof operationsofATXI.ATXI'stransmissionservicesrevenues increased$37millionin2015comparedwith2014because ofhigherratebaseinvestmentandrecoverablecostsunder 38 forward-lookingformularatemakingreducedbytherecognitionofapotentialrefundtocustomersbasedonthe pendingFERCcomplaintcasesregardingtheallowedbase returnoncommonequity.SeeNote2-Rateand RegulatoryMattersunderPartII,Item8,ofthisreportfor informationregardingtheFERCcomplaintcases.AmerenMissouriAmerenMissourihasaFACcostrecoverymechanismthatallowsittorecoverortorefund,throughcustomerrates,95%ofchangesinnetenergycostsgreaterorless thantheamountsetinbaserateswithoutatraditionalrate proceeding,subjecttoMoPSCprudencereviews.Netenergycosts,asdefinedintheFAC,includefuelandpurchasedpowercosts,includingtransportation,netof off-systemsales.AsofMay30,2015,transmission revenuesandsubstantiallyalltransmissionchargesare excludedfromnetenergycostsasaresultoftheApril2015 MoPSCelectricrateorder,whichunfavorablyaffected marginsasdiscussedbelow.AmerenMissouriaccruesasa regulatoryassetnetenergycoststhatexceedtheamount setinbaserates(FACunder-recovery).Netrecoveryof thesecoststhroughcustomerratesdoesnotaffectAmeren Missouri'selectricmargins,asanychangeinrevenueis offsetbyacorrespondingchangeinfuelexpensetoreduce thepreviouslyrecognizedFACregulatoryasset.AmerenMissouri'selectricmarginsincreased$45million,or2%,in2015comparedwith2014.The followingitemshadafavorableeffectonAmerenMissouri's electricmargins:

HigherMEEIAnetsharedbenefitscausedbyincreasedcustomerimplementationoflonger-livedenergy efficiencyofferingsandincreasednon-residential customerparticipation,whichincreasedrevenuesby

$33million.NetsharedbenefitscompensatedAmeren Missouriforlowersalesvolumesfromenergy-efficiency-relatedvolumereductionsincurrentand futureperiods.

Higherelectricbaserates,effectiveMay30,2015,asa resultoftheApril2015MoPSCelectricrateorder, whichincreasedmarginsbyanestimated$17million.

Thechangeinelectricbaseratesisthesumofthe changeinbaserates(estimate)(+$82million)andthe changeineffectofhighernetenergycostsincludedin baserates(-$65million)inthetableabove.ThefollowingitemshadanunfavorableeffectonAmerenMissouri'selectricmarginsin2015comparedwith

2014:LowersalesvolumesprimarilycausedbytheMEEIAprogramsandothercustomerenergyefficiency measures,andareductioninNorandasalesvolumes.

Excludingtheestimatedeffectofweatherandreduced salestoNoranda,totalretailsalesvolumesdecreased by1%,whichdecreasedrevenuesby$25million.A reductioninNorandasalesvolumesdecreased revenuesby$11million.Noranda'ssalesvolumeswerelowerthanthosereflectedinratesestablishedinthe April2015MoPSCelectricrateorder.Lowersales volumesledtoadecreaseinnetenergycostsof

$24million.Thechangeinnetenergycostsisthesum ofthechangeinoff-systemsalesandtransmission servicesrevenues(+$3million)andthechangein energycosts(+$21million)inthetableabove.

Wintertemperaturesin2015werewarmercompared with2014,asheatingdegree-daysdecreased19%.The effectofweatherdecreasedmarginsbyanestimated

$10million.Thechangeinmarginsduetoweatheris thesumoftheeffectofweather(estimate)onelectric revenues(-$20million)andtheeffectofweather (estimate)onfuelandpurchasedpower(+$10million) inthetableabove.

Theexclusionoftransmissionrevenuesand substantiallyalltransmissionchargesfromtheFAC beginningMay30,2015,whichdecreasedmarginsby

$6million.Thechangeinmarginsasaresultofthe changestotheFACisthesumofFACexclusionof transmissionservicesexpenses(-$7million)and transmissionservicesrevenues(+$1million)inthe tableabove.AmerenMissouri'snaturalgasmarginswerecomparablebetweentheyears.AmerenMissourihasacost recoverymechanismfornaturalgaspurchasedonbehalfof itscustomers.Thesepass-throughpurchasedgascostsdo notaffectAmerenMissouri'snaturalgasmarginsasany changeincostsisoffsetbyacorrespondingchangein

revenues.AmerenIllinoisAmerenIllinois'electricrevenuesincreased$161millionin2015comparedwith2014primarilyduetohigherpowersupplycostsasaresultofincreasedMISO capacityprices.AmerenIllinoishasacostrecovery mechanismforpowerpurchasedandtransmissionservices incurredonbehalfofitselectriccustomers.Thesepass-throughcostsdonotaffectAmerenIllinois'electric margins,asanychangeincostsisoffsetbya correspondingchangeinrevenues.TheprovisionsoftheIEIMAandtheFERC'selectrictransmissionformularateframeworkprovideforannual reconciliationsoftheelectricdeliveryandelectric transmissionservicerevenuerequirementsnecessaryto reflecttheactualcostsincurredinagivenyearwiththe revenuerequirementsincustomerratesforthatyear, includinganallowedreturnonequity.SeeOperationsand MaintenanceExpensesinthissectionforadditional informationregardingthecomponentsoftherevenue requirements.Ineachofthoseelectricjurisdictions,ifthe currentyear'srevenuerequirementisgreaterthanthe revenuerequirementreflectedinthatyear'scustomerrates, anincreasetoelectricoperatingrevenueswithanoffsettoa regulatoryassetisrecordedtoreflecttheexpectedrecovery ofthoseadditionalamountsfromcustomerswithinthenext twoyears.Ineachjurisdiction,ifthecurrentyear'srevenue requirementislessthantherevenuerequirementreflected 39 inthatyear'scustomerrates,areductiontoelectricoperatingrevenueswithanoffsettoaregulatoryliabilityis recordedtoreflecttheexpectedrefundtocustomerswithin thenexttwoyears.Theincreasesorreductionstoelectric operatingrevenuesareshowninbaserates(estimate)and transmissionservicesrevenues,inthetableabove,forthe electricdeliveryandelectrictransmissionservicerevenues, respectively.SeeNote2-RateandRegulatoryMatters underPartII,Item8,ofthisreportforinformation regardingAmerenIllinois'revenuerequirement reconciliationpursuanttotheIEIMA.AmerenIllinois'electricmarginsincreased$84million,or7%,in2015comparedwith2014.Thefollowingitems hadafavorableeffectonAmerenIllinois'electricmargins:

Electricdeliveryservicerevenuesthatincreasedby$34million,primarilybecauseofincreasedratebase investmentandhigherrecoverablecostsunderformula ratemakingpursuanttotheIEIMA.Theserevenues werereducedbyalowerreturnonequityforelectric deliveryserviceinvestmentsduetoareductioninthe 30-yearUnitedStatesTreasurybondyields.

Transmissionservicesrevenuesthatincreasedby

$29million,duetoahigherrevenuerequirement, drivenprimarilybyincreasedratebaseinvestmentand recoverablecostsunderforward-lookingformula ratemaking.Theserevenueswerereducedbythe recognitionofapotentialrefundtocustomersbasedon thependingFERCcomplaintcasesregardingthe allowedbasereturnoncommonequity.

AJanuary2015ICCorderregardingAmerenIllinois' cumulativepowerusagecostanditspurchasedpower ridermechanism,whichcausedelectricrevenuesto increaseby$15millioncomparedwith2014.AmerenIllinois'naturalgasrevenuesdecreased$193millionin2015comparedwith2014duetolower naturalgascommoditypricesandlowersalesvolumesdue toweather.AmerenIllinoishasacostrecoverymechanism fornaturalgaspurchasedonbehalfofitscustomers.These pass-throughpurchasedgascostsdonotaffectAmeren Illinois'naturalgasmargins,asanychangeincostsis offsetbyacorrespondingchangeinrevenues.AmerenIllinois'naturalgasmarginsdecreased$18million,or4%,in2015comparedwith2014.Winter temperaturesin2015werewarmercomparedwith2014as heatingdegree-daysdecreased18%,whichdecreased marginsbyanestimated$10million.Thechangein marginsduetoweatheristhesumoftheeffectofweather (estimate)onrevenues(-$72million)andtheeffectof weather(estimate)ongaspurchasedforresale

(+$62million)inthetableabove.2014versus2013AmerenCorporationAmeren'selectricmarginsincreased$147million,or4%,in2014comparedwith2013.Ameren'snaturalgasmarginsincreased$45million,or9%,in2014compared with2013.TheseresultswereprimarilydrivenbyAmeren MissouriandAmerenIllinoisresults,asdiscussedbelow.

Ameren'selectricmarginsalsoreflecttheresultsof operationsofATXI.ATXI'stransmissionservicesrevenues increased$14millionin2014comparedwith2013because ofhigherratebaseinvestmentandrecoverablecostsunder forward-lookingformularatemaking.Theserevenueswere reducedbytherecognitionofapotentialrefundto customersbasedonthependingNovember2013FERC complaintcaseregardingtheallowedbasereturnon commonequity.AmerenMissouriAmerenMissouri'selectricmarginsincreased$35million,or1%,in2014comparedwith2013.ThefollowingitemshadafavorableeffectonAmerenMissouri's electricmargins:

Theabsenceofachargein2014relatingtoaJuly2013MoPSCFACprudencerevieworder,whichdecreased 2013revenuesby$25million.AmerenMissouri recordedaFACprudencereviewchargein2013forits estimatedobligationtorefundtoitselectriccustomers theearningsassociatedwithsalesrecognizedby AmerenMissourifromOctober1,2009,toMay31, 2011.HigherMEEIAnetsharedbenefitsdrivenbyincreased customerparticipation,whichincreasedrevenueby

$15million.NetsharedbenefitscompensatedAmeren Missouriforlowersalesvolumesfromenergy-efficiency-relatedvolumereductionsincurrentand futureperiods.

Wintertemperaturesin2014werecoldercompared with2013,asheatingdegree-daysincreased5%.The effectofweatherincreasedmarginsbyanestimated

$3million.Thechangeinmarginsduetoweatheristhe sumoftheeffectofweatheronelectricrevenues

(+$8million)andtheeffectofweatheronfueland purchasedpower(-$5million)inthetableabove.AmerenMissouri'selectricmarginswereunfavorablyaffectedbylowersalesvolumesprimarilycausedbythe MEEIAprograms.Lowersalesvolumesfromenergy-efficiency-relatedvolumereductionswereoffsetbyMEEIA netsharedbenefits.Excludingtheestimatedeffectof weather,totalretailsalesvolumesdecreased1%,which decreasedrevenuesbyanestimated$22million,partially offsetbyadecreaseinnetenergycostsof$6million.The decreaseinnetenergycostsisthesumofthechangein energycosts(+$18million)andthechangeinoff-system salesandtransmissionservicesrevenues(-$12million)in thetableabove.AmerenMissouri'snaturalgasmarginswerecomparablebetweentheyears.

40 AmerenIllinoisAmerenIllinois'electricmarginsincreased$98million,or9%,in2014comparedwith2013.ThefollowingitemshadafavorableeffectonAmerenIllinois'electricmargins:

Electricdeliveryservicerevenuesthatincreasedby$56million,primarilybecauseofincreasedratebase investmentandhigherrecoverablecostsunderformula ratemakingpursuanttotheIEIMA.

Transmissionservicesrevenuesthatincreasedby

$10million,largelybecauseofahigherrevenue requirementdrivenprimarilybyincreasedratebase investmentandrecoverablecostsunderforward-lookingformularatemaking.Theserevenueswere reducedbytherecognitionofapotentialrefundto customersbasedonthependingNovember2013FERC complaintcaseregardingtheallowedbasereturnon commonequity.

Excludingtheestimatedeffectofweather,residential retailsalesvolumesthatincreased1%,whichincreased revenuesby$3million.AmerenIllinois'electricmarginswereunfavorablyaffectedbysummertemperaturesin2014thatweremilder comparedwith2013,ascoolingdegree-daysdecreased 6%,whichdecreasedmarginsbyanestimated$5million.AmerenIllinois'naturalgasmarginsincreased$44million,or11%,in2014comparedwith2013.The followingitemshadafavorableeffectonAmerenIllinois' naturalgasmargins:

HighernaturalgasdeliveryservicerateseffectiveJanuary2014,whichincreasedrevenuesbyan estimated$32million.

Wintertemperaturesin2014werecoldercompared with2013asheatingdegree-daysincreased6%.The effectofweatherincreasedmarginsbyanestimated

$4million.Thechangeinmarginsduetoweatheristhe sumoftheeffectofweatheronrevenues(+$32million) andtheeffectofweatherongaspurchasedforresale

(-$28million)inthetableabove.OtherOperationsandMaintenanceExpenses2015versus2014AmerenCorporationOtheroperationsandmaintenanceexpensesincreased$10millionin2015comparedwith2014.Otheroperations andmaintenanceexpensesdecreased$14millionatAmeren Missouriandincreased$26millionatAmerenIllinois.AmerenMissouriOtheroperationsandmaintenanceexpenseswere$14millionlowerin2015comparedwith2014.Thefollowingitemsdecreasedotheroperationsand maintenanceexpensesbetweenyears:

Areductionof$27millioninrefuelingandmaintenanceoutagecostsattheCallawayenergycenter,primarilyduetocostsforthe2014scheduledoutage.Costsfor the2014scheduledoutagewere$36million.There wasnorefuelingoutagescheduledin2015;however,

$9millioninpreparationcostswereincurredin2015 forthe2016scheduledoutage.

Adecreaseof$9millioninemployeebenefitcosts, primarilyduetoachangeinpensionandpostretirement expensesallowedinrates,asaresultoftheApril2015 MoPSCelectricrateorder.Electricrevenuesfrom customerbillingsdecreasedbyacorrespondingamount, withnooveralleffectonnetincome.

Areductionof$8millionindisposalcostsforlow-level radioactivenuclearwaste.

Adecreaseof$6millioninenergycentermaintenance costs,primarilyduetoreducedmajoroutagesatcoal-firedenergycenters.

Adecreaseof$3millioninbaddebtexpensedueto improvedcustomercollections.Thefollowingitemsincreasedotheroperationsandmaintenanceexpensesbetweenyears:

Amortizationof$17millioninpreviouslydeferredsolarrebatecosts,asaresultoftheApril2015MoPSC electricrateorder.Electricrevenuesfromcustomer billingsincreasedbyacorrespondingamount,withno overalleffectonnetincome.

Anincreaseof$16millioninMEEIAenergyefficiency programcostsin2015duetoprogramenhancements andincreasedcustomerparticipation.Electricrevenues fromcustomerbillingsincreasedbyacorresponding amount,withnooveralleffectonnetincome.

Anincreaseof$3millionduetoanunrealizedMTM lossin2015comparedwithagainin2014,resulting fromchangesinthemarketvalueofinvestmentsused tosupportAmeren'sdeferredcompensationplans.

Anincreaseof$2millioninelectricdistribution maintenanceexpenditures,primarilyrelatedto increasedsystemrepairwork.AmerenIllinoisPursuanttotheprovisionsoftheIEIMA'sandtheFERC'sformularateframeworks,recoverableelectricservice coststhatarenotrecoveredthroughseparatecostrecovery mechanismsareincludedinAmerenIllinois'revenue requirementreconciliations,whichresultincorresponding adjustmentstoelectricoperatingrevenues,withnooverall effectonnetincome.Theserecoverableelectricservice costsincludeotheroperationsandmaintenanceexpenses, depreciationandamortization,taxesotherthanincome taxes,interestcharges,andincometaxes.Otheroperationsandmaintenanceexpenseswere$26millionhigherin2015comparedwith2014.The followingitemsincreasedotheroperationsand maintenanceexpensesbetweenyears:

Anincreaseof$8millioninbaddebt,customerenergyefficiency,andenvironmentalremediationcosts.These expensesareincludedincostridersthatresultin 41 additionalelectricandnaturalgasrevenues,resultinginnooveralleffectonnetincome.

Anincreaseof$7millioninelectricdelivery maintenanceexpenditures,primarilyrelatedto increasedcircuitmaintenanceandsystemrepairwork asaresultofregulatorycompliancerequirements.

Anincreaseof$7millioninlaborcosts,primarily becauseofstaffadditionstomeetenhancedreliability standardsandcustomerservicegoalsrelatedtothe IEIMAandwageincreases.

Anincreaseof$3millioninstorm-relatedrepaircosts.

Anincreaseof$3millioninemployeebenefitcosts, primarilyduetohigherpensionandpostretirement expensescausedbychangesinactuarialassumptions andtheperformanceofplanassets.

Anincreaseof$2millionduetoanunrealizedMTM lossin2015comparedwithagainin2014,resulting fromchangesinthemarketvalueofinvestmentsused tosupportAmeren'sdeferredcompensationplans.2014versus2013AmerenCorporationOtheroperationsandmaintenanceexpensesincreased$73millionin2014comparedwith2013.Otheroperationsand maintenanceexpensesincreased$30millionatAmeren Missouriandincreased$78millionatAmerenIllinois.Partially offsettingtheincreasesatAmerenMissouriandAmeren Illinoisweredecreasedcorporateexpensesbetweenyearsof

$35million,primarilyduetothesubstantialeliminationof businessandadministrativecostspreviouslyincurredin supportofthedivestedmerchantgenerationbusiness.AmerenMissouriOtheroperationsandmaintenanceexpenseswere$30millionhigherin2014comparedwith2013.The followingitemsincreasedotheroperationsand maintenanceexpensesbetweenyears:

Anincreaseof$17millioninlaborcosts,primarilybecauseofwageincreases.

Anincreaseof$14millioninlitigationandasbestos claimcostsduetoseverallegalproceedings.

Anincreaseof$8millionindisposalcostsforlow-level radioactivenuclearwasteattheCallawayenergycenter.

Anincreaseof$7millioninMEEIAenergyefficiency programcostsin2014duetoincreasedcustomer

participation.

Areductionof$3millioninunrealizednetMTMgains, resultingfromchangesinthemarketvalueof investmentsusedtosupportAmeren'sdeferred compensationplans.Thefollowingitemsdecreasedotheroperationsandmaintenanceexpensesbetweenyears:

Areductionof$13millioninenergycentercosts,primarilyrelatedtocoalhandling.

Adecreaseof$7millioninstorm-relatedcostsdueto fewermajorstormsin2014.

Areductionof$2millioninrefuelingandmaintenance costsassociatedwiththescheduledCallawayoutages.

The2014outagecostswere$36millioncomparedwith 2013outagecostsof$38million.AmerenIllinoisOtheroperationsandmaintenanceexpenseswere$78millionhigherin2014comparedwith2013.The followingitemsincreasedotheroperationsand maintenanceexpensesbetweenyears:

Anincreaseof$29millioninbaddebt,customerenergyefficiency,andenvironmentalremediationcosts.

Anincreaseof$17millioninlaborcosts,primarily becauseofstaffadditionstomeetenhancedreliability standardsandcustomerservicegoalsrelatedtothe IEIMAandwageincreases.

Anincreaseof$13millioninelectricdelivery maintenanceexpenditures,primarilyrelatedtoincreased systemrepairandvegetationmanagementwork.

Anincreaseof$8millioninasbestosclaimcosts.

Anincreaseof$7millionininformationtechnology serviceexpenses,partiallyrelatedtotheIEIMA

implementation.

Anincreaseof$6millioninnaturalgascompliance expenditures,primarilyrelatedtopipelineintegritywork.

Anincreaseof$4millioninrentalexpense,primarily relatedtosoftwarefromaffiliatedcompanies.

Areductionof$2millioninunrealizednetMTMgains, resultingfromchangesinthemarketvalueof investmentsusedtosupportAmeren'sdeferred compensationplans.Otheroperationsandmaintenanceexpensesdecreasedbetweenyearsbecauseofareductioninemployeebenefit costsof$12million,primarilyduetolowerpensionand postretirementexpensescausedbychangesinactuarial assumptionsandtheperformanceofplanassets.ProvisionforCallawayConstructionandOperating LicensePrimarilybecauseofchangesinvendorsupportforlicensingeffortsattheNRC,AmerenMissouri'sassessment oflong-termcapacityneeds,decliningcostsofalternative generationtechnologies,andtheregulatoryframeworkin Missouri,AmerenMissouridiscontinueditseffortsto licenseandbuildasecondnuclearunitatitsexisting Callawayenergycentersitein2015.Asaresultofthis decision,AmerenandAmerenMissourirecognizeda

$69millionnoncashpretaxprovisionforallofthe previouslycapitalizedCOLcosts.SeeNote2-Rateand RegulatoryMattersunderPartII,Item8ofthisreportfor additionalinformation.

42 DepreciationandAmortization2015versus2014AmerenCorporationDepreciationandamortizationexpensesincreased$51millionin2015comparedwith2014,primarilybecauseofincreasedexpensesatAmerenMissouriandAmeren Illinois,asdiscussedbelow.AmerenMissouriDepreciationandamortizationexpensesincreased$19million,primarilybecauseofmultiplesignificantelectricprojectscompletedin2014andincreaseddepreciationrates resultingfromtheApril2015MoPSCelectricrateorder.AmerenIllinoisDepreciationandamortizationexpensesincreased$32million,primarilybecauseofelectricsystemcapitaladditionsandamortizationofnaturalgas-related

investments.2014versus2013AmerenCorporationDepreciationandamortizationexpensesincreased$39millionin2014comparedwith2013,primarilybecause ofincreasedexpensesatAmerenMissouriandAmeren Illinois,asdiscussedbelow.AmerenMissouriDepreciationandamortizationexpensesincreased$19million,primarilybecauseofelectricsystemcapital additions.AmerenIllinoisDepreciationandamortizationexpensesincreased$20million,primarilybecauseofelectricsystemcapital additions.TaxesOtherThanIncomeTaxes2015versus2014AmerenCorporationTaxesotherthanincometaxesincreased$5millionin2015comparedwith2014,primarilybecauseofincreasedexpensesatAmerenMissouri,partiallyoffsetbydecreased expensesatAmerenIllinois,asdiscussedbelow.SeeExcise TaxesinNote1-SummaryofSignificantAccounting PoliciesunderPartII,Item8,ofthisreportforadditional

information.AmerenMissouriTaxesotherthanincometaxesincreased$13million,primarilybecauseofincreasedpropertytaxesresultingfrombothhighertaxratesandassessedpropertytaxvalues,andincreasedgrossreceiptstaxesresultingfromhigherelectricservicerates.Thegrossreceiptstaxincrease hadnoeffectonnetincomeaselectricrevenuesforgross receiptstaxesfromcustomerbillingsincreasedbya correspondingamount.AmerenIllinoisTaxesotherthanincometaxesdecreased$8million,primarilybecauseofdecreasedgrossreceiptstaxesresultingfromlowernaturalgassalespricesandvolumes.

Naturalgasrevenuesforgrossreceiptstaxesfrom customerbillingsdecreasedbyacorrespondingamount, withnooveralleffectonnetincome.2014versus2013AmerenCorporationTaxesotherthanincometaxesincreased$10millionin2014comparedwith2013,primarilybecauseofincreased expensesatAmerenMissouriandAmerenIllinois,as discussedbelow.AmerenMissouriTaxesotherthanincometaxesincreased$3million,primarilybecauseofanincreaseinpropertytaxesresultingfromhighertaxratesandincreasedstateandlocal assessmentsin2014.AmerenIllinoisTaxesotherthanincometaxesincreased$6millionbecauseofa$3millionincreaseingrossreceiptstaxes,asaresultofhighernaturalgasratesandhighersales volumes,andbecauseofa$3millionincreaseinproperty taxesbetweenyears.OtherIncomeandExpenses2015versus2014AmerenCorporationOtherincome,netofexpenses,decreased$13millionin2015comparedwith2014,primarilybecauseofa$5millionincreaseincharitablecontributionsatAmeren (parent)duetotimingofcontributions,anditemsat AmerenMissouri,asdiscussedbelow.SeeNote6-Other IncomeandExpensesunderPartII,Item8,ofthisreport foradditionalinformation.AmerenMissouriOtherincome,netofexpenses,decreased$7million,primarilybecauseofadecreaseintheallowanceforequityfundsusedduringconstruction,asmultiplesignificant electriccapitalprojectswerecompletedin2014.AmerenIllinoisOtherincome,netofexpenses,wascomparablebetweenyears.

43 2014versus2013AmerenCorporationOtherincome,netofexpenses,increased$14millionin2014comparedwith2013,primarilybecauseofa$4millionreductionincharitablecontributionsatAmeren (parent)duetothetimingofcontributions,anincreasein Ameren(parent)interestincomefromanotereceivable withMarketingCompany,anditemsatAmerenIllinois,as discussedbelow.AmerenMissouriOtherincome,netofexpenses,wascomparablebetweenyears.

AmerenIllinoisOtherincome,netofexpenses,increased$8million,primarilybecauseofincreasedincomefromcustomer-requestedconstruction,andincreasedinterestincomeon boththeIEIMA2013and2014revenuerequirement reconciliationregulatoryassets.Adecreaseintheequity portionofallowanceforfundsusedduringconstruction, primarilyduetoincreasedusageofshort-termdebttofund capitalexpenditures,reducedthefavorableeffectofthe aboveitems.InterestCharges2015versus2014AmerenCorporationInterestchargesincreased$14millionin2015comparedwith2014.InterestchargesatAmeren(parent)decreasedby$13million,primarilybecauseofalower averageinterestrateondebtin2015.InMay2014,Ameren (parent)repaidatmaturity$425millionofseniorunsecured notes,withproceedsfromcommercialpaperissuances.In November2015,Ameren(parent)issued$700millionof seniorunsecurednotes,theproceedsofwhichwereused torepaycommercialpaperborrowings.Theinterest chargesreductionatAmeren(parent)wasoffset,inpart,by increasesininterestchargesatAmerenMissouriand AmerenIllinois,asdiscussedbelow.AmerenMissouriInterestchargesincreased$8million,primarilybecauseofadecreaseintheallowanceforfundsusedduringconstruction,asmultiplesignificantelectricprojects werecompletedin2014,andbecauseoftheissuanceof seniorsecurednotesinApril2015.AmerenIllinoisInterestchargesincreased$19million,becauseoftheissuancesofseniorsecurednotesinJune2014andDecember2014,theproceedsofwhichwereusedtorepay commercialpaperborrowings,andtheabsencein2015of an$11millionreductionfromanICCelectricrateorderreceivedinDecember2014,whichpartiallyreverseda chargerecordedin2013thathaddisallowedtherecovery fromcustomersofcertaindebtpremiumcosts.2014versus2013AmerenCorporationInterestchargesdecreased$57millionin2014comparedwith2013,primarilybecauseofa$24million reductionininterestchargesatAmeren(parent),asaresult ofthematurityof$425millionof8.875%seniorunsecured notesinMay2014,whichwasreplacedwithlowercost commercialpaper,andadecreaseininterestcharges associatedwithuncertaintaxpositionsatAmeren(parent).

Additionally,interestchargeswereloweratAmerenIllinois, asdiscussedbelow.AmerenMissouriInterestchargeswerecomparablebetweenyears.Theabsencein2014ofa2013reductiontointerestchargesassociatedwithuncertaintaxpositionsresultedinhigher interestcharges.SeeNote13-IncomeTaxesunderPartII, Item8,ofthisreportforinformationregardinguncertaintax positions.Thisincreasewaspartiallyoffsetbytheeffectof refinancingactivitiesthatresultedinhigher-costdebtbeing replacedwithlower-costdebt.AmerenIllinoisInterestchargesdecreased$31million.Therewasareductionininterestchargesassociatedwiththeregulatoryliabilityforthe2012IEIMArevenuerequirement reconciliationastherefundobligationwascompleted throughout2014.The2013and2014IEIMArevenue requirementreconciliationswerebothregulatoryassets, which,asdiscussedaboveunderOtherIncomeand Expenses,resultedininterestincome.Also,thefavorable effectofrefinancingactivitiesthatresultedinhigher-cost debtbeingreplacedwithlower-costdebtalsodecreased interestcharges.Additionally,theICCissuedanelectricrate orderinDecember2014,whichresultedinapartialreversal ofachargerecordedin2013associatedwithaDecember 2013ICCelectricrateorderthathaddisallowedthe recoveryfromcustomersofcertaindebtpremiumcosts.

SeeNote2-RateandRegulatoryMattersunderPartII, Item8,ofthisreportforadditionalinformation.IncomeTaxesThefollowingtablepresentseffectiveincometaxratesfortheyearsendedDecember31,2015,2014,and2013:201520142013 Ameren........................

38%39%38%AmerenMissouri

.................

37%37%38%AmerenIllinois

..................

37%41%40%SeeNote13-IncomeTaxesunderPartII,Item8,ofthisreportforinformationregardingreconciliationsofeffectiveincometaxrates.

44 Income(Loss)fromDiscontinuedOperations,Netof TaxesIn2015,basedoncompletionoftheIRSauditofAmeren's2013taxyear,Amerenrecognizedataxbenefitof

$53millionduetotheresolutionofanuncertaintax positionfromdiscontinuedoperations.Nomaterialactivity wasrecordedassociatedwithdiscontinuedoperationsin 2014.DuringtheyearendedDecember31,2013,theloss fromdiscontinuedoperations,netoftaxes,wasprimarily relatedtotheimpairmentlossandrelatedincometax effectsassociatedwiththeNewAERdivestiture.See Note16-DivestitureTransactionsandDiscontinued OperationsunderPartII,Item8,ofthisreportforadditional

information.LIQUIDITYANDCAPITALRESOURCESOurtariff-basedgrossmarginsareourprincipalsourceofcashfromoperatingactivities.Adiversifiedretailcustomermix,primarilyconsistingofrate-regulated residential,commercial,andindustrialcustomers,provides uswithareasonablypredictablesourceofcash.Inaddition tousingcashgeneratedfromoperatingactivities,weuse availablecash,borrowingsundertheCreditAgreements, commercialpaperissuances,moneypoolborrowings,or,in thecaseofAmerenMissouriandAmerenIllinois,othershort-termborrowingsfromaffiliatestosupportnormal operationsandtemporarycapitalrequirements.Wemay reduceourshort-termborrowingswithcashfrom operationsor,atourdiscretion,withlong-termborrowings, or,inthecaseofAmerenMissouriandAmerenIllinois,with capitalcontributionsfromAmeren(parent).Weexpectto makesignificantcapitalexpendituresoverthenextfive yearsasweinvestinourelectricandnaturalgasutility infrastructuretosupportoverallsystemreliability, environmentalcompliance,andotherimprovements.We intendtofundthosecapitalexpenditureswithavailablecash onhand,cashgeneratedfromoperatingactivities,and commercialpaperanddebtissuancessothatwemaintain anequityratioaround50%,assumingconstructive regulatoryenvironments.Theuseofcashfromoperatingactivitiesandshort-termborrowingstofundcapitalexpendituresandother long-terminvestmentsmayperiodicallyresultinaworking capitaldeficit,definedascurrentliabilitiesexceeding currentassets,aswasthecaseatDecember31,2015,for Ameren.Ameren'sworkingcapitaldeficitwasprimarilythe resultofcurrentmaturitiesoflong-termdebtand commercialpaperissuances.WiththeCreditAgreements andcashandcashequivalentsavailable,theAmeren Companieshadaccessto$1.8billionofcreditcapacity availableand$2.1billionofliquidityatDecember31,2015.Thefollowingtablepresentsnetcashprovidedby(usedin)operating,investingandfinancingactivitiesfortheyearsendedDecember31,2015,2014,and2013:NetCashProvidedBy(UsedIn)OperatingActivitiesNetCashProvidedby(UsedIn)InvestingActivitiesNetCashProvidedby(UsedIn)FinancingActivities201520142013201520142013201520142013 Ameren (a)-continuingoperations

.....$2,021$1,557$1,636$(1,951)$(1,856)$(1,440)$246$141$(149)

Ameren (a)-discontinuedoperations

....(4)(6)57 (25)139(283)---AmerenMissouri

...................

1,2479501,143 (724)(837)(687)

(325)(113)(603)AmerenIllinois

....................

763445651 (913)(828)(695) 22038345(a)IncludesamountsforAmerenregistrantandnonregistrantsubsidiariesandintercompanyeliminations.CashFlowsfromOperatingActivities2015versus2014AmerenCorporationAmeren'scashfromoperatingactivitiesassociatedwithcontinuingoperationsincreased$464millionin2015, comparedwith2014.Thefollowingitemscontributedtothe

increase:A$192millionincreaseresultingfromelectricand naturalgasmargins,asdiscussedinResultsof Operations,excludingcertainnoncashitems,aswellas thechangeincustomerreceivablebalances.

A$149millionincreaseinnetenergycostscollected fromAmerenMissouricustomersundertheFAC.

A$137millionincreaseincashassociatedwithAmeren Illinois'IEIMArevenuerequirementreconciliation adjustments,asAmerenIllinoiscollected$69million fromcustomersin2015andrefunded$68millionto customersin2014.

A$57milliondecreaseinAmerenMissourirebate paymentsprovidedforcustomer-installedsolar generationastherebateprogramwassubstantially completedbytheendof2014.

A$33millionincreaseinnaturalgascommoditycosts collectedfromcustomersunderthePGAs,primarily relatedtoAmerenIllinois.

A$31milliondecreaseinthecostofnaturalgasheldin storagecausedprimarilybylowergasprices.

A$19milliondecreaseinpaymentsfornuclear refuelingandmaintenanceoutagesattheAmeren MissouriCallawayenergycenter.Therewasno refuelingandmaintenanceoutagein2015;however, therewerecashexpendituresrelatedtothe2016spring outagemadein2015.

45 ThefollowingitemspartiallyoffsettheincreaseinAmeren'scashfromoperatingactivitiesassociatedwithcontinuingoperationsduring2015,comparedto2014:

A$49millionincreaseincoalinventorycostsatAmerenMissouricausedbyincreasedvolumes resultingfromtheabsenceofweather-relatedrailroad deliverydelaysthatoccurredin2014.

Anet$29milliondecreaseinreturnsofcollateral postedwithcounterparties,primarilyresultingfrom changesinthemarketpricesofpowerandnaturalgas andincontractedcommodityvolumes,partiallyoffset bytheeffectofcreditratingupgrades.

A$24milliondecreaseinincometaxrefundsprimarily duetotheabsencein2015oftaxsettlements pertainingto2007through2011thatwerereceivedin 2014.SeeNote1-SummaryofSignificantAccounting PoliciesunderPartII,Item8,ofthisreportforincome taxrefundinformation.

A$24millionincreaseinpensionandpostretirement benefitplancontributionscausedbyachangein actuarialassumptions.

A$7millionincreaseinpropertytaxpaymentsat AmerenMissouricausedbybothhigherassessed propertytaxvaluesandtaxrates.

A$7millionincreaseinexpendituresforcustomer energyefficiencyprogramscomparedwithamounts collectedfromAmerenIllinoiscustomers.Ameren'scashfromoperatingactivitiesassociatedwithdiscontinuedoperationswascomparablebetween 2015and2014.AmerenMissouriAmerenMissouri'scashfromoperatingactivitiesincreased$297millionin2015,comparedwith2014.Thefollowingitemscontributedtotheincrease:

A$149millionincreaseinnetenergycostscollectedfromcustomersundertheFAC.

A$143milliondecreaseinincometaxespaidto Ameren(parent)pursuanttothetaxallocation agreement,primarilyrelatedtoachangeinthetax treatmentforgenerationrepairsadoptedin2013, whichincreasedpaymentsin2014.

A$57milliondecreaseinrebatepaymentsprovidedfor customer-installedsolargenerationastherebate programwassubstantiallycompletedbytheendof

2014.A$37millionincreaseresultingfromelectricand naturalgasmargins,asdiscussedinResultsof Operations,excludingcertainnoncashitems,aswellas thechangeincustomerreceivablebalances.

A$19milliondecreaseinpaymentsforscheduled nuclearrefuelingandmaintenanceoutagesatthe Callawayenergycenter.Therewasnorefuelingand maintenanceoutagein2015;however,therewerecash expendituresrelatedtothe2016springoutagemadein

2015.ThefollowingitemspartiallyoffsettheincreaseinAmerenMissouri'scashfromoperatingactivitiesduring 2015,comparedto2014:

A$49millionincreaseincoalinventorycostscausedbyincreasedvolumesresultingfromtheabsenceof weather-relatedrailroaddeliverydelaysthatoccurredin

2014.Anet$12milliondecreaseinreturnsofcollateral postedwithcounterparties,primarilyresultingfrom changesinthemarketpricesofpowerandnaturalgas andincontractedcommodityvolumes,partiallyoffset bytheeffectofcreditratingupgrades.

An$11millionincreaseinpensionandpostretirement benefitplancontributionscausedbyachangein actuarialassumptions.

A$7millionincreaseinpropertytaxpaymentscaused bybothhigherassessedpropertytaxvaluesandtax

rates.AmerenIllinoisAmerenIllinois'cashfromoperatingactivitiesincreased$318millionin2015,comparedwith2014.The followingitemscontributedtotheincrease:

A$137millionincreaseincashassociatedwithIEIMArevenuerequirementreconciliationadjustments,as

$69millionwascollectedfromcustomersin2015and

$68millionwasrefundedtocustomersin2014.

A$101millionincreaseresultingfromelectricand naturalgasmargins,asdiscussedinResultsof Operations,excludingcertainnoncashitems,aswellas thechangeincustomerreceivablebalances.

A$69millionincreaseinincometaxesrefunds, pursuanttothetaxallocationagreementwithAmeren (parent),primarilyrelatedtodeductionsforaccelerated depreciationandincreasedcapitalexpenditures.

A$31millionincreaseinnaturalgascommoditycosts collectedfromcustomersunderthePGA.

A$26milliondecreaseinthecostofnaturalgasheldin storagecausedprimarilybylowergasprices.ThefollowingitemspartiallyoffsettheincreaseinAmerenIllinois'cashfromoperatingactivitiesduring2015, comparedwith2014:

Anet$17milliondecreaseinreturnsofcollateralpostedwithcounterparties,primarilyresultingfrom changesinthemarketpricesofpowerandnaturalgas andincontractedcommodityvolumes,partiallyoffset bytheeffectofcreditratingupgrades.

A$12millionincreaseinpensionandpostretirement benefitplancontributionscausedbyachangein actuarialassumptions.

A$7millionincreaseinexpendituresforcustomer energyefficiencyprogramscomparedwithamounts collectedfromcustomers.

46 2014versus2013AmerenCorporationAmeren'scashfromoperatingactivitiesassociatedwithcontinuingoperationsdecreased$79millionin2014,comparedwith2013.Thefollowingitemscontributedtothe

decrease:An$89milliondecreaseinthecashassociatedwithAmerenMissouri'sunder-recoveredFACcosts.

Deferralsandrefundsexceededrecoveriesin2014by

$49million,whilerecoveriesexceededdeferralsin 2013by$40million.

The2014refundstoAmerenIllinoiscustomersof

$67millionasrequiredundertheprovisionsofthe IEIMAforthe2012revenuerequirementreconciliation adjustment,comparedwithnorefundsin2013.

A$65milliondifferenceinexpendituresforcustomer energyefficiencyprogramscomparedwithamounts collectedfromAmerenMissouriandAmerenIllinois

customers.

A$50millionincreaseincoalpurchasescausedby increasedvolumesandprices.AmerenMissouri purchasedlesscoalin2013due,inpart,todelivery disruptionsfromflooding.

A$42milliondifferenceinpurchasedpower commoditycostsincurredcomparedwithamounts collectedfromAmerenIllinois'customers.

A$39millionincreaseinrebatepaymentsprovidedfor customer-installedsolargenerationatAmeren

Missouri.A$38milliondecreaseinnaturalgascommoditycosts collectedfromcustomersunderthePGAs,primarily relatedtoAmerenIllinois.

Adecreaseof$26millionatAmerenMissouriand AmerenIllinoisforstormrestorationassistance providedtononaffiliatedutilities,primarilydueto HurricaneSandyin2013.

A$26millionincreaseinpaymentstocontractorsat AmerenIllinoisforadditionalreliability,maintenance, andIEIMAprojects.

Refundsof$24milliontocustomersasrequiredbya September2014FERCorderinAmerenIllinois' wholesaledistributionratecase.

A$23millionincreaseinthevalueofnaturalgasheld instorageatAmerenIllinoisbecauseofincreased marketpricesandtimingofinjectionsandwithdrawals.

A$22milliondecreaseassociatedwithstock-based compensationawards.

A$21millionincreaseinlaborcostsatAmerenIllinois, primarilybecauseofwageincreasesandstaffadditions tomeetenhancedreliabilityandcustomerservicegoals relatedtotheIEIMA.

A$21milliondifferenceintransmissionservicecosts incurredcomparedwithamountscollectedfrom customers,primarilyatAmerenIllinois.

Anet$19milliondecreaseinreturnsofcollateral postedwithcounterpartiesduetochangesatAmeren MissouriandAmerenIllinoisdiscussedbelow.

A$17millionincreaseinthepurchaseofreceivables fromalternativeretailelectricsupplierscomparedwith amountscollectedfromAmerenIllinoiscustomers.

A$16milliondecreaseincontributionsreceivedby AmerenIllinoisfromcustomersforfutureconstruction.

An$8millionincreaseinpropertytaxpaymentsat AmerenMissouricausedbyhigherassessedproperty taxvaluesandincreasedpropertytaxrates.ThefollowingitemspartiallyoffsetthedecreaseinAmeren'scashfromoperatingactivitiesassociatedwith continuingoperationsduring2014,comparedwith2013:

A$240millionincreaseresultingfromelectricandnaturalgasmargins,asdiscussedinResultsof Operations,excludingcertainnoncashitems,aswellas thechangeincustomerreceivablebalances.

Incometaxrefundsof$41millionin2014,primarily duetofederalsettlementsforthetaxyears2007 through2011,comparedwithincometaxpaymentsin 2013of$116million.SeeNote1-Summaryof SignificantAccountingPoliciesunderPartII,Item8,of thisreportforincometaxpayment(refund)

information.

A$76milliondecreaseinpensionandpostretirement benefitplancontributions.InadditiontotheAmeren MissouriandAmerenIllinoisamountsdiscussed below,Ameren'snonregistrantsubsidiaries' contributionstothepensionandpostretirementbenefit plansdecreased$30million.

A$29milliondecreaseininterestpayments,primarily duetorefinancingactivityatAmerenMissouriand Ameren(parent).SeeNote1-SummaryofSignificant AccountingPoliciesunderPartII,Item8,ofthisreport forinterestpaymentinformationasitrelatesto continuinganddiscontinuedoperations.

A$27millioninsurancereceiptin2013atAmeren MissourirelatedtotheDecember2005breachofthe upperreservoirattheTaumSaukpumped-storage hydroelectricenergycenter.Ameren'scashfromoperatingactivitiesassociatedwithdiscontinuedoperationsdecreasedin2014,compared with2013.The2013activityrelatedtothedisposedNew AERandtheElgin,GibsonCityandGrandTowerenergy centers.The2014activityrelatedtotransactioncostsand taxpaymentsassociatedwiththeElgin,GibsonCity,and GrandTowerenergycenters.AmerenMissouriAmerenMissouri'scashfromoperatingactivitiesdecreased$193millionin2014,comparedwith2013.Thefollowingitemscontributedtothedecrease:

A$129millionincreaseinincometaxpaymentspaidtoAmeren(parent)pursuanttothetaxallocation agreement,resultingprimarilyfromfewerdeductionsfor capitalexpendituresfortaxyears2007through2013, whichcausedincreasedpaymentsin2014.Theincrease waspartiallyoffsetbyareductioninpaymentsduetothe useofnetoperatinglosscarryforwardsin2014.

47 An$89milliondecreaseinthecashassociatedwithAmerenMissouri'sunder-recoveredFACcosts.

Deferralsandrefundsexceededrecoveriesin2014by

$49million,whilerecoveriesexceededdeferralsin 2013by$40million.

A$50millionincreaseincoalpurchasescausedby increasedvolumesandprices.AmerenMissouri purchasedlesscoalin2013,due,inpart,todelivery disruptionsfromflooding.

A$39millionincreaseinrebatepaymentsprovidedfor customer-installedsolargeneration.

A$28milliondifferenceinexpendituresforcustomer energyefficiencyprogramscomparedwithamounts collectedfromcustomers.

An$11milliondecreaseinnaturalgascommodity costscollectedfromcustomersunderthePGA.

Adecreaseof$10millionforstormrestoration assistanceprovidedtononaffiliatedutilities,primarily relatedtoHurricaneSandyin2013.

An$8millionincreaseinpropertytaxpaymentscaused byhigherassessedpropertytaxvaluesandincreased propertytaxrates.ThefollowingitemspartiallyoffsetthedecreaseinAmerenMissouri'scashfromoperatingactivitiesduring 2014,comparedwith2013:

A$96millionincreaseresultingfromelectricandnaturalgasmargins,asdiscussedinResultsof Operations,excludingcertainnoncashitems,aswellas thechangeincustomerreceivablebalances.

A$27millioninsurancereceiptin2013relatedtothe December2005breachoftheupperreservoiratthe TaumSaukpumped-storagehydroelectricenergycenter.

A$26milliondecreaseinpensionandpostretirement benefitplancontributions.

Anet$10millionincreaseinreturnsofcollateral postedwithcounterpartiesprimarilyresultingfrom changesinthemarketpricesofpowerandnaturalgas andincontractedcommodityvolumes.

A$9milliondecreaseininterestpayments,primarily duetorefinancingactivity.AmerenIllinoisAmerenIllinois'cashfromoperatingactivitiesdecreased$206millionin2014,comparedwith2013.The followingitemscontributedtothedecrease:

The2014refundstocustomersof$67millionasrequiredundertheprovisionsoftheIEIMAforthe2012 revenuerequirementreconciliationadjustment, comparedwithnorefundsin2013.

A$42milliondifferenceinpurchasedpower commoditycostsincurredcomparedwithamounts collectedfromcustomers.

A$37milliondifferenceinexpendituresforcustomer energyefficiencyprogramscomparedwithamounts collectedfromcustomers.

Anet$29milliondecreaseinreturnsofcollateral postedwithcounterparties,primarilyresultingfromchangesinthemarketpricesofpowerandnaturalgas andincontractedcommodityvolumes.

A$27milliondecreaseinnaturalgascommoditycosts collectedfromcustomersunderthePGA.

A$26millionincreaseinpaymentstocontractorsfor additionalreliability,maintenance,andIEIMAprojects.

Refundstocustomersof$24millionasrequiredbya September2014FERCorderinthewholesale distributionratecase.

A$23millionincreaseinthevalueofnaturalgasheld instoragebecauseofincreasedmarketpricesandthe timingofinjectionsandwithdrawals.

A$21millionincreaseinlaborcosts,primarilybecause ofwageincreasesandstaffadditionstomeetenhanced reliabilityandcustomerservicegoalsrelatedtothe

IEIMA.A$20milliondifferenceintransmissionservicecosts incurredcomparedwithamountscollectedfrom

customers.

A$17millionincreaseinthepurchaseofreceivables fromalternativeretailelectricsupplierscomparedwith amountscollectedfromcustomers.

A$16milliondecreaseincontributionsreceivedfrom customersforfutureconstruction.

Theabsenceof$16millionreceivedin2013forstorm restorationassistanceprovidedtononaffiliatedutilities, primarilyduetoHurricaneSandy.ThefollowingitemspartiallyoffsetthedecreaseinAmerenIllinois'cashfromoperatingactivitiesduring2014, comparedwith2013:

Electricandnaturalgasmargins,asdiscussedinResultsofOperationsexcludingcertainnoncashitems, thatincreasedby$126million.

A$21millionincreaseinincometaxrefundsfrom Ameren(parent)pursuanttothetaxallocation agreement,resultingprimarilyfromtheexpecteduseof netoperatinglosscarryforwardsin2014.

A$20milliondecreaseinpensionandpostretirement benefitplancontributions.PensionPlansAmeren'spensionplansarefundedincompliancewithincometaxregulations,federalfunding,andother regulatoryrequirements.Asaresult,Amerenexpectsto funditspensionplansatalevelequaltothegreaterofthe pensionexpenseorthelegallyrequiredminimum contribution.ConsideringAmeren'sassumptionsat December31,2015,itsinvestmentperformancein2015, anditspensionfundingpolicy,Amerenexpectstomake annualcontributionsof$40millionto$70millionineachof thenextfiveyears,withaggregateestimatedcontributions of$280million.WeexpectAmerenMissouri'sandAmeren Illinois'portionsofthefuturefundingrequirementstobe 40%and50%,respectively.Theseamountsareestimates.

Theestimatesmaychangewithactualinvestment performance,changesininterestrates,changesinour assumptions,changesingovernmentregulations,orany voluntarycontributions.In2015,Amerencontributed 48

$111milliontoitspensionplans.SeeNote11-RetirementBenefitsunderPartII,Item8,ofthisreportforadditional

information.CashFlowsfromInvestingActivities2015versus2014Ameren'scashusedininvestingactivitiesassociatedwithcontinuingoperationsincreasedby$95millionduring2015,comparedwith2014.Capitalexpendituresincreased

$132million,becauseofincreasedtransmission expenditures,whichincludeda$174millionincreasefor ATXIprimarilyrelatedtotheIllinoisRiversproject,and increasedAmerenIllinoiscapitalexpenditurespartially offsetbydecreasedexpendituresatAmerenMissouri.During2015,Ameren'scashusedininvestingactivitiesassociatedwithdiscontinuedoperationsconsisted ofa$25millionpaymentforaliabilityassociatedwiththe NewAERdivestiture.During2014,cashprovidedby investingactivitiesassociatedwithAmeren'sdiscontinued operationsconsistedof$152millionreceivedfrom RocklandCapitalforthesaleoftheElgin,GibsonCity,and GrandTowergas-firedenergycentersinJanuary2014, offsetbypaymentof$13milliontoIPHforthefinalworking capitaladjustmentandcertainliabilitiesassociatedwiththe NewAERdivestiture.AmerenMissouri'scashusedininvestingactivitiesdecreasedby$113millionduring2015,comparedwith 2014.Capitalexpendituresdecreased$125million, primarilybecauseseverallargeprojectswerecompletedin 2014.Nuclearfuelexpendituresdecreasedby$22million becauseofthetimingofpurchasesin2015comparedwith 2014.Inaddition,cashusedininvestingactivitiesincreased in2015becauseofnetadvancestothemoneypoolof

$36million;therewerenoadvancesin2014.AmerenIllinois'cashusedininvestingactivitiesincreasedby$85millionduring2015,comparedwith2014, becauseofincreasedcapitalexpenditures,primarilyfor reliability,IEIMAprojects,andtransmission.2014versus2013Ameren'scashusedininvestingactivitiesassociatedwithcontinuingoperationsincreasedby$416millionduring2014,comparedwith2013.Capitalexpenditures increased$406million,primarilybecauseofincreased transmissionexpenditures,whichincludeda$150million increaseforATXI'sIllinoisRiversproject.Inaddition, capitalexpendituresforenergycenter,reliabilityandIEIMA projectsincreasedcashusedininvestingactivitiesandare discussedbelow.During2014,cashprovidedbyinvestingactivitiesassociatedwithAmeren'sdiscontinuedoperations consistedof$152millionreceivedfromRocklandCapital forthesaleoftheElgin,GibsonCity,andGrandTowergas-firedenergycentersinJanuary2014,offsetbypaymentof

$13milliontoIPHforthefinalworkingcapitaladjustment andaportionofcertainliabilitiesassociatedwiththeNewAERdivestiture.Incomparison,cashusedininvesting activitiesassociatedwithdiscontinuedoperationsduring 2013was$283million,primarilybecauseofthe requirementtoleave$235millionwithNewAERupon divestiture,pursuanttothetransactionagreementwithIPH.AmerenMissouri'scashusedininvestingactivitiesincreasedby$150millionduring2014,comparedwith 2013.Capitalexpendituresincreased$99million,primarily forreliabilityandenergycenterprojects,includingthe nuclearreactorvesselheadreplacementprojectatits Callawayenergycenter,theelectrostaticprecipitator upgradesattheLabadieenergycenter,anewsubstationin St.Louis,andinvestmentintheO'Fallonenergycenter, offsetbyareductioninstormrestorationexpenditures.

Nuclearfuelexpendituresincreasedby$29millionbecause ofthetimingofpurchasesin2014comparedwith2013.In addition,cashusedininvestingactivitiesincreasedin2014 becauseoftheabsencein2014of$24millioninnet receiptsrelatedtomoneypooladvancesreceivedin2013.AmerenIllinois'cashusedininvestingactivitiesincreased$133millionduring2014,comparedwith2013, becauseofincreasedcapitalexpenditures,primarilyfor transmission,reliability,andIEIMAprojects.CapitalExpendituresThefollowingtablepresentsthecapitalexpendituresbytheAmerenCompaniesfortheyearsendedDecember31,2015,2014,and2013:201520142013 Ameren (a)................$1,917$1,785$1,379AmerenMissouri

..........

622747648AmerenIllinois

............

918835701(a)IncludesamountsforAmerenregistrantandnonregistrantsubsidiariesandtheeliminationofintercompanytransfers.Ameren's2015capitalexpendituresconsistedofexpendituresmadebyitssubsidiariesincludingATXI,which spent$375millionprimarilyontheIllinoisRiversproject.

AmerenIllinoisspent$288millionontransmissionprojects and$134milliononIEIMAprojects.Othercapital expendituresweremadeprincipallytomaintain,upgrade, andimprovethereliabilityofthetransmissionand distributionsystemsofAmerenMissouriandAmeren IllinoisaswellastofundvariousAmerenMissourienergy centerupgrades.Ameren's2014capitalexpendituresconsistedofexpendituresmadebyitssubsidiariesincludingATXI,which spent$201millionontheIllinoisRiversproject.Ameren Missourispent$101millionforelectrostaticprecipitator upgradesatitsLabadieenergycenter,$33millionforthe replacementofthenuclearreactorvesselheadatits Callawayenergycenter,and$16millionfortheconstruction oftheO'Fallonenergycenter.AmerenIllinoisspent

$284millionontransmissioninitiativesand$89millionon IEIMAprojects.Othercapitalexpendituresweremade principallytomaintain,upgrade,andimprovethereliability 49 ofthetransmissionanddistributionsystemsofAmerenMissouriandAmerenIllinois,aswellastofundvarious AmerenMissourienergycenterupgrades.Ameren's2013capitalexpendituresconsistedofexpendituresmadebyitssubsidiariesincludingATXI,which spent$51millionontheIllinoisRiversproject.Ameren Missourispent$53millionforelectrostaticprecipitator upgradesattheLabadieenergycenter,$30millionon stormrestoration,and$29milliononthereplacementof thenuclearreactorvesselheadatitsCallawayenergycenter whichwasinstalledduringthe2014refuelingand maintenanceoutage.AmerenIllinoisspent$269millionon transmissioninitiatives,$33milliononIEIMAprojects,and

$23milliononstormrestoration.Othercapitalexpenditures weremadeprincipallytomaintain,upgrade,andimprove thereliabilityofthetransmissionanddistributionsystems ofAmerenMissouriandAmerenIllinoisaswellastofund variousAmerenMissourienergycenterupgrades.InDecember2015,afederaltaxlawwasenactedthatauthorizedthecontinueduseofbonusdepreciationthat allowsforanaccelerationofdeductionsfortaxpurposes.

Bonusdepreciationisexpectedtoincreasecashflow throughatleast2020.Amerenexpectstousethis incrementalcashflowtomakecapitalinvestmentsinutility infrastructureforthebenefitofitscustomers.Withoutthese investments,thebonusdepreciationwouldreducerate base,whichwouldreduceourrevenuerequirementsand futureearningsgrowth.Theimpactofbonusdepreciation onAmerenMissouri,AmerenIllinois,andATXIwillvary basedoninvestmentlevelsateachcompany.ThefollowingtablepresentsAmeren'sestimateofcapitalexpendituresthatwillbeincurredfrom2016through 2020,includingconstructionexpenditures,allowancefor fundsusedduringconstruction,andexpendituresfor compliancewithexistingenvironmentalregulations.

Amerenexpectstoallocatemoreofitscapitalexpenditures toAmerenIllinoisandATXIbased,inpart,onthemore constructiveregulatoryframeworkswithinwhichthey operate.Theseestimatesdonotincludetheimpactsofthe CleanPowerPlan.SeeNote15-Commitmentsand ContingenciesunderPartII,Item8,ofthisreportfor additionalinformationregardingtheCleanPowerPlan.20162017-2020 TotalAmerenMissouri..$835$3,095-$3,420$3,930-$4,255AmerenIllinois....9054,820-5,3255,725-6,230ATXI...........410565-625975-1,035Other...........510-1515-20Ameren.........$2,155$8,490-$9,385$10,645-$11,540AmerenMissouri'sestimatedcapitalexpendituresincludetransmission,distribution,andgeneration-relatedinvestments,aswellasexpendituresforcompliancewith environmentalregulations.AmerenIllinois'estimated capitalexpendituresareprimarilyforelectricandnatural gastransmissionanddistribution-relatedinvestments, capitalexpenditurestomodernizeitsdistributionsystem pursuanttotheIEIMA,andcapitalexpendituresforqualifiedinvestmentsinnaturalgasinfrastructureundertheQIP rider.ATXI'sestimatedcapitalexpendituresinclude expendituresforthethreeMISO-approvedmulti-value transmissionprojects.Foradditionalinformationregarding theIEIMAcapitalexpenditurerequirements,theQIPrider, andATXI'stransmissionprojects,seePartI,Item1,ofthis

report.AmerenMissouricontinuallyreviewsitsgenerationportfolioandexpectedpowerneeds.Asaresult,Ameren Missouricouldmodifyitsplanforgenerationcapacity,the typeofgenerationassettechnologythatwillbeemployed, andwhethercapacityorpowermaybepurchased,among otherchanges.Additionally,wecontinuallyreviewthe reliabilityofourtransmissionanddistributionsystems, expectedcapacityneeds,andopportunitiesfortransmission investments.Thetimingandamountofinvestmentscould varybecauseofchangesinexpectedcapacity,thecondition oftransmissionanddistributionsystems,andourability andwillingnesstopursuetransmissioninvestments, amongotherfactors.Anychangesinfuturegeneration, transmission,ordistributionneedscouldresultin significantcapitalexpendituresorlosses,whichcouldbe material.Compliancewithenvironmentalregulationscould alsohavesignificantimpactsonthelevelofcapital

expenditures.EnvironmentalCapitalExpendituresAmerenMissouriwillincursignificantcostsinfutureyearstocomplywithfederalandstateregulationsincludingthoserequiringthereductionofSO 2,NO x,mercury,andCO 2emissionsfromitscoal-firedenergycenters.SeeNote15-CommitmentsandContingenciesunderPartII,Item8,of thisreportforadiscussionofexistingenvironmentallaws andregulationsthataffect,ormayaffect,ourfacilitiesand capitalexpenditurestocomplywithsuchlawsand

regulations.CashFlowsfromFinancingActivities2015versus2014Ameren'sfinancingactivitiesassociatedwithcontinuingoperationsprovidednetcashof$246millionin2015,comparedwith$141millionin2014.During2015, Ameren(parent)receivedproceedsof$700millionfrom long-termdebtissuancesandrepaidshort-termdebtin additiontotheactivityatAmerenMissouriandAmeren Illinoistofundmaturitiesoflong-termdebtandrepay short-termdebtdiscussedbelow.In2015,theissuancesof long-termdebt,netofrepaymentsforshort-termdebtand forlong-termdebtatmaturity,alongwithcashprovidedby operatingactivitieswereusedtofundinvestingactivities andpaydividends.Incomparison,during2014,Ameren anditsregistrantsubsidiariesissuedlong-termandshort-termdebttofundthematuritiesandredemptionsoflong-termdebt,includingthematurityofAmeren(parent)'s

$425millionseniorunsecurednotes.Thesefinancing activities,alongwithcashprovidedbyoperatingactivities whereusedtofundinvestingactivitiesandpaydividends.

50 Nocashfromfinancingactivitieswasusedfordiscontinuedoperationsduring2015.AmerenMissouri'sfinancingactivitiesusednetcashof$325millionin2015,comparedwith$113millionin2014.During2015,AmerenMissourireceivedproceedsof

$249millionfromalong-termdebtissuance,repaidanet

$97millionofshort-termdebt,repaidatmaturity

$114millionoflong-termdebt,andreceiveda$224million contributionfromAmeren(parent).Incomparison,during 2014,AmerenMissourireceivedproceedsof$350million fromalong-termdebtissuanceandanet$97millionof short-termdebt,repaidatmaturity$104millionoflong-termdebt,andrepaid$105milliontothemoneypool.In bothyears,thesefinancingactivities,alongwithcash providedbyoperatingactivitieswhereusedtofund investmentactivitiesandpaydividends.AmerenIllinois'financingactivitiesprovidednetcashof$220millionin2015,comparedwith$383millionin 2014.During2015,AmerenIllinoisreceivedproceedsof

$248millionfromalong-termdebtissuance,repaidanet

$32millionofshort-termdebt,andrepaid$15millionto themoneypool.Incomparison,during2014,Ameren Illinoisreceivedproceedsof$548millionfromtwolong-termdebtissuancesandanet$32millionofshort-term debt,repaidexistinglong-termdebtof$163million,and repaid$41milliontothemoneypool.Inbothyears,these financingactivities,alongwithcashprovidedbyoperating activitieswhereusedtofundinvestmentactivities.2014versus2013Ameren'sfinancingactivitiesassociatedwithcontinuingoperationsprovidednetcashof$141millionin2014,comparedwith2013whenAmerenusedcashof

$149million.During2014,Amerenanditsregistrant subsidiariesissuedlong-termandshort-termdebttofund thematuritiesandredemptionsoflong-termdebt,including thematurityofAmeren(parent)'s$425millionsenior unsecurednotes.In2014,Amerenusedcashfromthese financingactivities,alongwithcashprovidedbyoperating activitiestofundinvestingactivitiesandpaydividends.In comparison,during2013,Amerenanditsregistrant subsidiariesissuedlong-termandshort-termdebttofund thematuritiesandredemptionsoflong-debtandtofundthe

$235millionthatAmerenwasrequiredtoleavewithNewAERuponitsdivestitureinDecember2013,pursuanttothe transactionagreementwithIPH.In2013,Amerenused cashonhand,cashfromtheissuancesofdebt,alongwith cashprovidedbyoperatingactivitiestofundinvesting activitiesandpaydividends.Nocashfromfinancingactivitieswasusedfordiscontinuedoperationsduring2014.AmerenMissouri'sfinancingactivitiesusednetcashof$113millionin2014,comparedwith$603millionin2013.

During2014,AmerenMissourireceivedproceedsof

$350millionfromalong-termdebtissuanceandanet

$97millionfromshort-termdebt,repaidatmaturity

$104millionoflong-termdebt,repaid$105milliontothe moneypool.Incomparison,during2013,AmerenMissouri repaid$244millionoflong-termdebt,andreceived

$105millionfromthemoneypool.Inbothyears,including cashonhandduring2013,thesefinancingactivities,along withcashprovidedbyoperatingactivitieswereusedtofund investmentactivitiesandpaydividends.AmerenIllinois'financingactivitiesprovidednetcashof$383millionin2014,comparedwith$45millionin 2013.During2014,AmerenIllinoisreceivedproceedsof

$548millionfromtwolong-termdebtissuancesandanet

$32millionfromshort-termdebt,repaidexistinglong-term debtof$163million,andrepaid$41milliontothemoney pool.Incomparison,during2013,AmerenIllinoisreceived proceedsof$278millionfromalong-termdebtissuance, repaidatmaturity$150millionoflong-termdebt,andpaid dividends.Inbothyears,thesefinancingactivities,along withcashprovidedbyoperatingactivitieswereusedtofund investmentactivities.CreditFacilityBorrowingsandLiquidityTheliquidityneedsofAmeren,AmerenMissouri,andAmerenIllinoisaretypicallysupportedthroughtheuseofavailablecash,short-termintercompanyborrowings, drawingsundercommittedbankcreditagreements,or commercialpaperissuances.SeeNote4-Short-termDebt andLiquidityunderPartII,Item8,ofthisreportfor additionalinformationoncreditagreements,short-term borrowingactivity,commercialpaperissuances,relevant interestrates,andborrowingsunderAmeren'smoneypool

arrangements.

51 ThefollowingtablepresentsAmeren'sconsolidatedliquidityasofDecember31,2015:AvailableatDecember31,2015AmerenandAmerenMissouri:MissouriCreditAgreement-borrowingcapacity.........................................................$

1,000Less:Ameren(parent)commercialpaperoutstanding...................................................176MissouriCreditAgreement-creditavailable 824AmerenandAmerenIllinois:IllinoisCreditAgreement-borrowingcapacity

...........................................................

1,100Less:Ameren(parent)commercialpaperoutstanding...................................................125Less:Lettersofcredit............................................................................13IllinoisCreditAgreement-creditavailable................................................................962TotalCreditAvailable$1,786Cashandcashequivalents...............................................................................292TotalLiquidity........................................................................................$

2,078BorrowingsbyAmerenundereitheroftheCreditAgreementsaredueandpayablenolaterthanthematuritydate,whileborrowingsbyAmerenMissouriandAmeren Illinoisaredueandpayablenolaterthantheearlierofthe maturitydateor364daysafterthedateofsuchborrowing (subjecttotherightofeachborrowertore-borrowin accordancewiththetermsoftheapplicableCredit Agreement).TheCreditAgreementsarecurrentlyscheduled tomatureinDecember2019,butthematuritydatemaybe extendedonceortwiceforadditionaloneyearperiodsupon mutualconsentoftheborrowersandlenders.TheCredit Agreementsareusedtoborrowcash,toissuelettersof credit,andtosupportissuancesunderAmeren's,Ameren Missouri's,andAmerenIllinois'commercialpaper programs.EitheroftheCreditAgreementsareavailableto AmerentosupportissuancesunderAmeren'scommercial paperprogram,subjecttoborrowingsublimits.The MissouriCreditAgreementisavailabletosupportissuances underAmerenMissouri'scommercialpaperprogram.The IllinoisCreditAgreementisavailabletosupportissuances underAmerenIllinois'commercialpaperprogram.During 2015,borrowingsundertheAmeren,AmerenMissouri,and AmerenIllinoiscommercialpaperprogramswereavailable atlowerinterestratesthantheinterestratesofborrowings undertheCreditAgreements.Assuch,commercialpaper issuanceswereapreferredsourceofthird-partyshort-term debtrelativetocreditfacilityborrowings.Thefollowingtablepresentsthemaximumaggregateamountavailabletoeachborrowerundereachfacility:

MissouriCreditAgreement IllinoisCreditAgreement Ameren..............$700$500AmerenMissouri.......800(a)AmerenIllinois.........(a)800(a)Notapplicable.Subjecttoapplicableregulatoryshort-termborrowingauthorizations,thesecreditarrangementsarealsoavailable toAmeren'sothersubsidiariesthroughdirectshort-term borrowingsfromAmeren,including,butnotlimitedto, AmerenServices,throughamoneypoolagreement.

Amerenhasmoneypoolagreementswithandamongits subsidiariestocoordinateandtoprovideforcertainshort-termcashandworkingcapitalrequirements.Ameren MissouriandAmerenIllinoisborrowfromtheutilitymoney poolwhenfundsareavailablebeforeutilizingtheCredit Agreementsandcommercialpaperprogramsbecausethe utilitymoneypoolinterestratesaretypicallylower.See Note4-Short-termDebtandLiquidityunderPartII, Item8,ofthisreportforadetailedexplanationofthemoney poolarrangements.Theissuanceofshort-termdebtsecuritiesbyAmeren'sutilitysubsidiariesissubjecttoapprovalbythe FERCundertheFederalPowerAct.InJanuary2016, AmerenMissourirequestedanextensionofitsexisting FERCauthorizationtoissueupto$1billionofshort-term debtsecuritiesthroughMarch2018.AmerenMissouri expectsFERCapprovalofthatauthorizationinMarch2016.

InSeptember2014,theFERCissuedanorderauthorizing AmerenIllinoistoissueupto$1billionofshort-termdebt securitiesthroughSeptember15,2016.InJuly2015,the FERCissuedanorderauthorizingATXItoissueupto

$300millionofshort-termdebtsecuritiesthroughJuly14, 2017.TheAmerenCompaniescontinuallyevaluatetheadequacyandappropriatenessoftheirliquidity arrangementsforchangingbusinessconditions.When businessconditionswarrant,changesmaybemadeto existingcreditagreementsortoothershort-termborrowing

arrangements.

52 Long-termDebtandEquityThefollowingtablepresentstheissuances(netofissuancediscounts),redemptions,repurchases,andmaturitiesoflong-termdebtfortheyearsendedDecember31,2015,2014,and2013fortheAmerenCompanies.TheAmerenCompaniesdidnotissueanycommonstockorredeemorrepurchaseanypreferredstockduringtheyearsended2015,2014,and2013.In 2015and2014,AmerenMissourireceivedcashcapitalcontributionsof$224millionand$215million,respectively,from Ameren(parent).Foradditionalinformationrelatedtothetermsandusesoftheseissuancesandeffectiveregistration statements,seeNote5-Long-termDebtandEquityFinancingsunderPartII,Item8,ofthisreport.MonthIssued,Redeemed,Repurchased,orMatured201520142013 IssuancesAmeren(parent)2.70%Seniorunsecurednotesdue2020

...........................

November$350$-$-3.65%Seniorunsecurednotesdue2026

...........................

November 350--AmerenMissouri:3.50%Seniorsecurednotesdue2024

.............................

April-350-3.65%Seniorsecurednotesdue2045

.............................

April 249--AmerenIllinois:4.80%Seniorsecurednotesdue2043

.............................

December--2784.30%Seniorsecurednotesdue2044

.............................

June-248-3.25%Seniorsecurednotesdue2025

.............................

December-300-4.15%Seniorsecurednotesdue2046

.............................

December 248--Totallong-termdebtissuances

.....................................$1,197$898$278Redemptions,Repurchases,andMaturities Ameren(Parent):8.875%Seniorunsecurednotesdue2014..........................May

$-$425$-AmerenMissouri:CityofBowlingGreencapitallease(PenoCreekCT)

..................

December 6 5519935.45%Seriespollutioncontrolrevenuebondsdue2028

..........

October--444.65%Seniorsecurednotesdue2013

.............................

October--2005.50%Seniorsecurednotesdue2014.............................May

-104-4.75%Seniorsecurednotesdue2015

.............................

April 114--AmerenIllinois:8.875%Seniorsecurednotesdue2013

............................

December--1505.90%Series1993due2023 (a)...................................

January-32-5.70%1994ASeriesdue2024 (a).................................

January-36-5.95%1993SeriesC-1due2026

.................................

January-35-5.70%1993SeriesC-2due2026

.................................

January-8-5.40%1998ASeriesdue2028

...................................

January-19-5.40%1998BSeriesdue2028

...................................

January-33-Totallong-termdebtredemptions,repurchases,andmaturities

............$120$697$399(a)Lessthan$1millionprincipalamountofthebondsremainoutstandingafterredemption.InFebruary2016,AmerenMissouri's5.40%seniorsecurednotesmaturedandwererepaidusingavailablecashandcommercialpaperborrowings.InJune2015,Ameren,AmerenMissouri,andAmerenIllinoisfiledaFormS-3shelfregistrationstatement registeringtheissuanceofanindeterminateamountof certaintypesofsecurities.Theregistrationstatement becameeffectiveimmediatelyuponfiling.Itwillexpirein June2018.TheAmerenCompaniesmaysellsecuritiesregisteredundertheireffectiveregistrationstatementsifmarket conditionsandcapitalrequirementswarrantsuchsales.

AnyofferandsalewillbemadeonlybymeansofaprospectusthatmeetstherequirementsoftheSecurities Actof1933andtherulesandregulationsthereunder.IndebtednessProvisionsandOtherCovenantsAtDecember31,2015,theAmerenCompanieswereincompliancewiththeprovisionsandcovenantscontainedwithintheircreditagreements,indentures,andarticlesof incorporation.SeeNote4-Short-termDebtandLiquidity andNote5-Long-termDebtandEquityFinancingsunder PartII,Item8,ofthisreportforadiscussionofcovenants andprovisions(andapplicablecross-defaultprovisions) containedinourcreditagreementsandincertainofthe AmerenCompanies'indenturesandarticlesof

incorporation.

53 Weconsideraccesstoshort-termandlong-termcapitalmarketstobeasignificantsourceoffundingforcapitalrequirementsnotsatisfiedbycashgeneratedfrom ouroperatingactivities.Inabilitytoraisecapitalon reasonableterms,particularlyduringtimesofuncertaintyin thecapitalmarkets,couldnegativelyaffectourabilityto maintainandexpandourbusinesses.Afterassessingits currentoperatingperformance,liquidity,andcreditratings (seeCreditRatingsbelow),Ameren,AmerenMissouri,and AmerenIllinoiseachbelievesthatitwillcontinuetohave accesstothecapitalmarkets.However,eventsbeyond Ameren's,AmerenMissouri's,andAmerenIllinois'control maycreateuncertaintyinthecapitalmarketsormake accesstothecapitalmarketsuncertainorlimited.Such eventscouldincreaseourcostofcapitalandadversely affectourabilitytoaccessthecapitalmarkets.DividendsandReturnofCapitalAmerenpaidtoitsshareholderscommonstockdividendstotaling$402million,or$1.655pershare,in2015,$390million,or$1.61pershare,in2014,and

$388million,or$1.60pershare,in2013.TheamountandtimingofdividendspayableonAmeren'scommonstockarewithinthesolediscretionof Ameren'sboardofdirectors.Ameren'sboardofdirectorshas notsetspecifictargetsorpayoutparameterswhendeclaring commonstockdividends,butitconsidersvariousfactors, includingAmeren'soverallpayoutratio,payoutratiosofour peers,projectedcashflowandpotentialfuturecashflow requirements,historicalearningsandcashflow,projected earnings,impactsofregulatoryordersorlegislation,and otherkeybusinessconsiderations.Amerenexpectsits dividendpayoutratiotobebetween55%and70%of earningsoverthenextfewyears.OnFebruary12,2016,the boardofdirectorsofAmerendeclaredaquarterlydividendon Ameren'scommonstockof42.5centspershare,payableon March31,2016,toshareholdersofrecordonMarch9,2016.Certainofourfinancialagreementsandcorporateorganizationaldocumentscontaincovenantsandconditions that,amongotherthings,restricttheAmerenCompanies' paymentofdividendsincertaincircumstances.AmerenIllinois'articlesofincorporationrequireitsdividendpaymentsoncommonstocktobebasedonratios ofcommonstocktototalcapitalizationandotherprovisions relatedtocertainoperatingexpensesandaccumulationsof earnedsurplus.Additionally,Amerenhascommittedtothe FERCtomaintainaminimumof30%equityinitscapital structureatAmerenIllinois.AmerenMissouriandAmerenIllinois,aswellascertainothernonregistrantAmerensubsidiaries,aresubject toSection305(a)oftheFederalPowerAct,whichmakesit unlawfulforanyofficerordirectorofapublicutility,as definedintheFederalPowerAct,toparticipateinthe makingorpayingofanydividendfromanyfunds"properly includedincapitalaccount."TheFERChasconsistently interpretedtheprovisiontoallowdividendstobepaidas longas(1)thesourceofthedividendsisclearlydisclosed, (2)thedividendsarenotexcessive,and(3)thereisnoself-dealingonthepartofcorporateofficials.Ataminimum, Amerenbelievesthatdividendscanbepaidbyits subsidiariesthatarepublicutilitiesfromnetincomeand fromretainedearnings.Inaddition,underIllinoislaw, AmerenIllinoismaynotpayanydividendonitsstock unless,amongotherthings,itsearningsandearnedsurplus aresufficienttodeclareandpayadividendafterprovisionis madeforreasonableandproperreserves,orunlessAmeren IllinoishasspecificauthorizationfromtheICC.AtDecember31,2015,theamountofrestrictednetassetsofwhollyownedsubsidiariesofAmerenthatmay notbedistributedtoAmerenintheformofaloanor dividendwas$2.3billion.ThefollowingtablepresentscommonstockdividendspaidbyAmerenCorporationtoitscommonshareholdersandbyAmerenMissouriandAmerenIllinoistotheirparent,Ameren:201520142013AmerenMissouri

.............................................................................$575$340 (a)$460AmerenIllinois

..............................................................................

--110 Ameren....................................................................................

402390388(a)Additionally,during2014,AmerenMissourireturnedcapitalof$215milliontoAmeren(parent).AmerenMissouriandAmerenIllinoiseachhaveissuedpreferredstock,whichprovidesforcumulativepreferred stockdividends.Eachcompany'sboardofdirectors considersthedeclarationofthepreferredstockdividendsto shareholdersofrecordonacertaindate,statingthedateonwhichthedividendispayableandtheamounttobepaid.

SeeNote5-Long-termDebtandEquityFinancingsunder PartII,Item8,ofthisreportforfurtherdetailconcerning thepreferredstockissuances.

54 ContractualObligationsThefollowingtablepresentsourcontractualobligationsasofDecember31,2015.SeeNote11-RetirementBenefitsunderPartII,Item8,ofthisreportforinformationregardingexpectedminimumfundinglevelsforourpensionplans.Theseexpectedpensionfundingamountsarenotincludedinthetablebelow.Inaddition,routineshort-termpurchaseorder commitmentsarenotincluded.Lessthan1Year 1-3 Years 3-5 YearsAfter5YearsTotal Ameren: (a)Long-termdebtandcapitalleaseobligations (b)...........................$395$1,521$1,023$4,392$7,331Interestpayments (c)................................................3626264352,7714,194Operatingleases (d).................................................1425233092Otherobligations (e).................................................1,3231,6765571,1284,684Totalcashcontractualobligations.....................................$2,094$3,848$2,038$8,321$16,301AmerenMissouri:Long-termdebtandcapitalleaseobligations (b)...........................$266$814$673$2,382$4,135Interestpayments (c)................................................2113672591,6872,524Operatingleases (d).................................................1222212984Otherobligations (e).................................................8331,1783254692,805Totalcashcontractualobligations.....................................$1,322$2,381$1,278$4,567$9,548AmerenIllinois:

Long-termdebt (b)..................................................$129$707$-$1,660$2,496Interestpayments (c)................................................1292151321,0191,495Operatingleases (d).................................................12216Otherobligations (e).................................................452479232659 1,822Totalcashcontractualobligations.....................................$711$1,403$366$3,339$5,819(a)IncludesamountsforregistrantandnonregistrantAmerensubsidiariesandintercompanyeliminations.(b)Excludesunamortizeddiscountandpremiumanddebtissuancecostsof$56million,$25million,and$25millionatAmeren,AmerenMissouri,andAmerenIllinois,respectively.SeeNote5-Long-termDebtandEquityFinancingsunderPartII,Item8ofthisreport,fordiscussionof itemsincludedherein.(c)Theweighted-averagevariable-ratedebthasbeencalculatedusingtheinterestrateasofDecember31,2015.

(d)Amountsforcertainland-relatedleaseshaveindefinitepaymentperiods.Theannualobligationof$3million,$2million,and$1millionforAmeren,AmerenMissouri,andAmerenIllinois,respectively,fortheseitemsisincludedintheLessthan1Year,1-3Years,and3-5Years columns.SeeLeasesinNote15-CommitmentsandContingenciesunderPartII,Item8ofthisreport,fordiscussionofitemsincludedherein.(e)SeeOtherObligationsinNote15-CommitmentsandContingenciesunderPartII,Item8ofthisreport,fordiscussionofitemsincludedherein.AsofDecember31,2015,Ameren,AmerenMissouri,andAmerenIllinoishadnounrecognizedtaxbenefits(detriments)foruncertaintaxpositions.Off-Balance-SheetArrangementsAtDecember31,2015,noneoftheAmerenCompanieshadoff-balance-sheetfinancingarrangements,otherthanoperatingleasesenteredintointheordinarycourseof business,lettersofcredit,andAmerenparentguarantee arrangementsonbehalfofitssubsidiaries.Noneofthe AmerenCompaniesexpecttoengageinanysignificantoff-balance-sheetfinancingarrangementsinthenearfuture.CreditRatingsOurcreditratingsaffectourliquidity,ouraccesstothecapitalmarketsandcreditmarkets,ourcostofborrowing underourcreditfacilities,ourcommercialpaperprograms, andourcollateralpostingrequirementsundercommodity

contracts.ThefollowingtablepresentstheprincipalcreditratingsoftheAmerenCompaniesbyMoody'sandS&Peffectiveon thedateofthisreport:Moody'sS&P Ameren:Issuer/corporatecreditrating

...............Baa1BBB+Seniorunsecureddebt

....................Baa1BBBCommercialpaper.......................P-2A-2AmerenMissouri:

Issuer/corporatecreditrating

...............Baa1BBB+Secureddebt...........................A2ASeniorunsecureddebt

....................Baa1BBB+Commercialpaper.......................P-2A-2AmerenIllinois:

Issuer/corporatecreditrating...............A3 BBB+Secureddebt...........................A1ASeniorunsecureddebt....................A3 BBB+Commercialpaper.......................P-2A-2 55 Thecostofborrowingunderourcreditfacilitiescanalsofluctuatedependinguponthecreditratingsoftheborrower.Acreditratingisnotarecommendationtobuy, sell,orholdsecurities.Itshouldbeevaluatedindependently ofanyotherrating.Ratingsaresubjecttorevisionor withdrawalatanytimebytheratingorganization.CollateralPostingsAnyadversechangeinourcreditratingsmayreduceaccesstocapitalandtriggeradditionalcollateralpostingsandprepayments.Suchchangesmayalsoincreasethecost ofborrowing,resultinginanadverseeffectonearnings.

Cashcollateralpostingsandprepaymentsmadewith externalparties,includingpostingsrelatedtoexchange-tradedcontracts,andcashcollateralpostedbyexternal partieswereimmaterialatAmeren,AmerenMissouri,and AmerenIllinoisatDecember31,2015.Sub-investment-gradeissuerorseniorunsecureddebtrating(lowerthan "BBB-"or"Baa3")atDecember31,2015,couldhave resultedinAmeren,AmerenMissouri,orAmerenIllinois beingrequiredtopostadditionalcollateralorother assurancesforcertaintradeobligationsamountingto

$143million,$72million,and$71million,respectively.Changesincommoditypricescouldtriggeradditionalcollateralpostingsandprepayments.Basedoncredit ratingsatDecember31,2015,ifmarketpriceswere15%

higherorlowerthanDecember31,2015levelsinthenext 12monthsand20%higherorlowerthereafterthroughthe endofthetermofthecommoditycontracts,thenAmeren, AmerenMissouri,orAmerenIllinoiswouldonlyberequired topostanimmaterialamountofcollateralorother assurancesforcertaintradeobligations.

OUTLOOKWeseektoearncompetitivereturnsoninvestmentsinourbusinesses.Weareseekingtoimproveourregulatoryframeworksandcostrecoverymechanismsand simultaneouslypursuingconstructiveregulatoryoutcomes withinexistingframeworks.Weareseekingtoalignour overallspending,bothoperatingandcapital,witheconomic conditionsandwithregulatoryframeworksestablishedby ourregulators.Consequently,wearefocusedon minimizingthegapbetweenallowedandearnedreturnson equity.Weintendtoallocatecapitalresourcestoour businessopportunitiesthatweexpecttoofferthemost attractiverisk-adjustedreturnpotential.Belowaresomekeytrends,events,anduncertaintiesthatarereasonablylikelytoaffectourresultsofoperations, financialcondition,orliquidity,aswellasourabilityto achievestrategicandfinancialobjectives,for2016and

beyond.Operations Ourstrategyforearningcompetitivereturnsonourinvestmentsinvolvesmeetingcustomerenergyneedsinanefficientfashion,workingtoenhanceregulatory frameworks,makingtimelyandwell-supportedrate casefilings,andaligningoverallspendingwiththose ratecaseoutcomes,economicconditions,andreturn

opportunities.

AmerencontinuestopursueitsplanstoinvestinFERC-regulatedelectrictransmission.MISOhasapproved threeelectrictransmissionprojectstobedevelopedby ATXI.Thefirstproject,IllinoisRivers,involvesthe constructionofatransmissionlinefromwestern IndianaacrossthestateofIllinoistoeasternMissouri.

Thelastsectionofthisprojectisexpectedtobe completedby2019.TheSpoonRiverprojectin northwestIllinoisandtheMarkTwainprojectin northeastMissouriaretheothertwoMISO-approved projectstobeconstructedbyATXI.Thesetwoprojects areexpectedtobecompletedin2018.TheIllinois RiversandtheSpoonRiverprojectshavereceivedallof thenecessarycommissionapprovalstoauthorizetheir constructionwhileATXIisstillseekingapprovalfrom theMoPSCfortheMarkTwainproject.Thetotal investmentinallthreeprojectsisexpectedtobemore than$1.0billionfrom2016through2019.Thistotal includesover$60millionofinvestmentbyAmeren Illinoistoconstructconnectionstoitsexisting transmissionsystem.Inadditiontoitsinvestmentin theMISO-approvedprojects,AmerenIllinoisexpectsto invest$1.9billioninelectrictransmissionassetsfrom 2016through2020toaddressloadgrowthand reliabilityrequirements.

BothAmerenIllinoisandATXIuseaforward-looking ratecalculationwithanannualrevenuerequirement reconciliationforeachcompany'selectrictransmission business.Withtheratesthatbecameeffectiveon January1,2016,andthecurrentlyallowed12.38%

returnonequity,the2016revenuerequirementfor AmerenIllinois'electrictransmissionbusinesswould be$241million,whichrepresentsa$42million increaseoverthe2015revenuerequirementduetorate basegrowth.Theseratesreflectacapitalstructure composedof51.9%commonequityandaprojected ratebaseof$1.2billion.Withtheratesthatbecame effectiveonJanuary1,2016,andthecurrentlyallowed 12.38%returnonequity,the2016revenue requirementforATXI'selectrictransmissionbusiness wouldbe$140million,whichrepresentsa$60million increaseoverthe2015revenuerequirementduetorate basegrowth,primarilyasaresultoftheIllinoisRivers project.Theseratesreflectacapitalstructure composedof56.1%commonequityandaprojected ratebaseof$0.9billion.

The12.38%returnoncommonequityisthesubjectof twoFERCcomplaintproceedings,theNovember2013 complaintcaseandtheFebruary2015complaintcase, thatchallengetheallowedbasereturnoncommon equityforMISOtransmissionowners.InDecember 2015,aFERCadministrativelawjudgeissuedaninitial decisionintheNovember2013complaintcasethat wouldlowertheallowedbasereturnoncommonequity 56 to10.32%.TheFERCisexpectedtoissueafinalorderontheNovember2013complaintcasebyOctober 2016.Aninitialdecisionfromanadministrativelaw judgeintheFebruary2015complaintcaseisexpected tobeissuedbyJune30,2016,whichwillsubsequently requireFERCapproval.A50basispointreductionin theFERC-allowedbasereturnoncommonequitywould reduceAmeren'sandAmerenIllinois'annualearnings byanestimated$6millionand$3million,respectively, basedoneachcompany's2016projectedratebase.

AmerenandAmerenIllinoisrecordedcurrent regulatoryliabilitiesontheirrespectivebalancesheets asofDecember31,2015,representingtheirestimate ofthepotentialrefundsfromtheNovember2013 refundeffectivedatethroughDecember2015.

InJanuary,2015,aFERC-approvedincentiveadderof upto50basispointsontheallowedbasereturnon commonequityforourparticipationinanRTObecame effective.Upontheissuanceofthefinalorder addressingtheNovember2013complaintcase, beginningwithitsJanuary2015effectivedate,the incentiveadderwillreduceanyrefundtocustomers relatingtoareductionofthebasereturnoncommon

equity.InApril2015,theMoPSCissuedanorderapprovinga

$122millionincreaseinAmerenMissouri'sannual revenuesforelectricservice,including$109million relatedtotheincreaseinnetenergycostsabovethose includedinbaseratespreviouslyauthorizedbythe MoPSC.Therevenueincreasewasbasedona9.53%

returnoncommonequity,acapitalstructurecomposed of51.8%commonequity,andaratebaseof

$7.0billiontoreflectinvestmentsthrough December31,2014.Ratechangesconsistentwiththe orderbecameeffectiveonMay30,2015.Ameren Missouri'srevenuerequirement,priortoMay30,2015, wasbasedona9.8%returnoncommonequity,a capitalstructurecomposedof52.3%commonequity, andaratebaseof$6.8billion.Accordingly,thelevelof earningsreflectedintherevenuerequirementineffect afterMay30,2015,islowerthanthelevelofearnings reflectedinthepreviouslyeffectiverevenue requirement.TheorderapprovedAmerenMissouri's requestforcontinueduseoftheFAC;however,it changedtheFACtoexcludealltransmissionrevenues andsubstantiallyalltransmissioncharges.Theorder didnotapprovethecontinueduseofregulatory trackingmechanismsforstormcostsorforvegetation managementandinfrastructureinspectioncosts.These changestoAmerenMissouri'srecoverymechanisms areexpectedtocontributetoregulatorylag.For example,theApril2015MoPSCelectricrateorder included$29millionoftransmissionchargesinbase ratesthatwerepreviouslyincludedintheFAC.Ameren Missouriexpectstransmissionchargestoincreaseto

$53millionin2016,withfurthercostincreases expectedintheforeseeablefuture.However, transmissionrevenuesincludedinbaseratesinthe April2015MoPSCelectricrateordertotaled$34millionandareexpectedtoremainrelatively constantin2016andintothenearfuture.

AmerenMissourisupplieselectricitytoNoranda's aluminumsmelterlocatedinsoutheastMissouri.Inits April2015electricrateorder,theMoPSCapproveda ratedesignthatestablished$78millioninannual revenues,netoffuelandpurchasedpowercosts,as Noranda'sportionofAmerenMissouri'srevenue requirement.TheportionofAmerenMissouri'sannual revenuerequirementreflectedinNoranda'selectricrate isbasedonthesmelterusingapproximately4.2million megawatthoursannually,whichisalmost100%ofits operatingcapacity.InJanuary2016,Noranda announcedthatproductionhadbeenidledattwoofits threepotlinesfollowinganelectricsupplycircuitfailure andthatthethirdpotline,whichwasnotdirectly affectedbythecircuitfailure,willbecurtailedonor beforeMarch12,2016,unlessNoranda"isableto secureasubstantiallymoresustainablepowerrate."

OnFebruary8,2016,Norandafiledvoluntarypetitions foracourt-supervisedrestructuringprocessunder Chapter11oftheUnitedStatesBankruptcyCode.In thefiling,Norandareaffirmedthattheremainingpot linewillcontinuetooperateatthesmelteruntilMarch 2016,atwhichtimeoperationofthelinewillbe curtailed.Norandastateditwouldmaintainthe flexibilitytorestartoperationsatthesmeltershould conditionsallow.Asaresultoftheseeventsin2016, actualsalesvolumestoNorandawillbesignificantly belowthesalesvolumesreflectedinratesand therefore,AmerenMissouriwillnotfullyrecoverits revenuerequirementuntilratesareadjustedbythe MoPSCinafutureelectricratecasetoreflect Noranda'sactualsalesvolumes.AmerenMissouri estimatesa$32millionreductionin2016earnings, comparedto2015,relatingtothesignificantlylower expectedelectricsalesvolumestoNorandaafter considerationoftheFACprovisionthatallowsAmeren Missouritoretainaportionofitsoff-systemsales.In January2016,AmerenMissourifiledanoticewiththe MoPSCthatwouldenableAmerenMissouritofilean electricratecaseafter60days.AmerenMissouri expectstofileanelectricratecasein2016andexpects theresultingnewratestoreflectNoranda'sactualsales volumeswhichwouldprospectivelyeliminatethe impactofthecurrentrevenueshortfall.Ratecase proceedingstakeplaceoveraperiodofupto 11monthsfromthedateoffiling.AmerenMissouri willcontinuetomonitorNoranda'ssalesvolumesand toevaluateitsregulatoryandlegislativeoptionsthat mightmitigateadversefinancialimpacts.

From2013through2015,AmerenMissouriinvested

$134millionincustomerenergyefficiencyprograms andrealized$174millionofnetsharedbenefitsunder theMEEIAplanapprovedinAugust2012.Additionally, theplanestablishedaperformanceincentivethatwould provideAmerenMissourianopportunitytoearn additionalrevenuesbasedonitsachievementofcertain customerenergyefficiencygoals,including$19million 57 if100%ofthegoalswereachievedduringthethree-yearperiod,withthepotentialtoearnmoreifAmeren Missouri'senergysavingsexceededthosegoals.In June2015,theMoPSCstafffiledacomplaintcasewith theMoPSCregardingthemethodandinputsusedin calculatingtheperformanceincentivefor2014and 2015.InNovember2015,theMoPSCissuedanorder thatadoptedtheMoPSCstaff'smethodandinputs usedincalculatingtheperformanceincentivefor2014 and2015.AmerenMissourihasfiledanappealofthe orderwiththeMissouriCourtofAppeals,Western District.IftheMissouriCourtofAppealsupholdsthe MoPSCorder,theperformanceincentiveawardedfrom the2014and2015MEEIAprogramswillbe significantlylessthantheperformanceincentive calculatedusingAmerenMissouri'sinterpretation.

AmerenMissourihasnotrecordedrevenuesassociated withtheperformanceincentiveforanyoftheMEEIA programyears.AmerenMissouribelievesitwill ultimatelybefoundtohaveexceeded100%ofthe customerenergyefficiencygoals,andittherefore expectstorecognizerevenuesofatleast$19millionin

2016.NetsharedbenefitscompensatedAmerenMissourifor thecurrentyearandlonger-termfinancialimpactsof customerenergyefficiencyprogramsineachyearof theprogramfrom2013through2015.TheMarch2016 throughFebruary2019MEEIAplanisdesigned differently.Thethroughputdisincentiveincludedinthe March2016throughFebruary2019MEEIAplanis designedtomakeAmerenMissouriearningsneutral eachyearforitscustomerenergyefficiency investments,includingthelostsalesvolumethatoccur inthatyear,anddoesnotcompensateforthelonger-termfinancialimpactsofcustomerenergyefficiency programsuntilthosesalesvolumesarelostinafuture year.Theunfavorableeffectsofsalesvolume reductionsin2016fromthe2013through2015energy efficiencyprogramswerepreviouslyrecognizedduring thoseyearsasnetsharedbenefitsand,therefore,any suchlostsalesvolumeswillnegativelyimpact2016

earnings.InFebruary2016,theMoPSCissuedanorder approvingAmerenMissouri'sMarch2016toFebruary 2019MEEIAplanwhichincludedaportfolioof customerenergyefficiencyprogramsalongwitharider tocollecttheprogramcosts,thethroughput disincentive,andaperformanceincentivefrom customers.Thethroughputdisincentiverecoverywill replacethenetsharedbenefitsthatwerecollected underthe2013through2015MEEIAplan.TheMEEIA riderwillallowAmerenMissouritocollectthe throughputdisincentivewithoutatraditionalrate proceedinguntilsuchtimeaslowervolumesresulting fromtheMEEIAprogramsarereflectedinbaserates.

Customerrateswillbebaseduponbothforecasted programcostsandthroughputdisincentivewhichwill beannuallyreconciledtoactualresults.BeginninginMarch2016,AmerenMissouriintendstoinvest

$158millionoverthethree-yearperiodincustomer energyefficiencyprograms.Inaddition,similartothe MEEIAplanthatendedinDecember2015,the MoPSC'sorderapprovedaperformanceincentivethat wouldprovideAmerenMissourianopportunitytoearn additionalrevenuesbyachievingcertaincustomer energyefficiencygoals,including$27millionif100%

ofthegoalsareachievedduringthethree-yearperiod, withthepotentialtoearnmoreifAmerenMissouri's energysavingsexceedthosegoals.AmerenMissouri mustachieveatleast25%ofitsenergyefficiencygoals beforeitearnsaperformanceincentive.

TheIEIMAprovidesforanannualreconciliationofthe revenuerequirementnecessarytoreflecttheactual costsincurredinagivenyearwiththerevenue requirementthatwasreflectedincustomerratesfor thatyear.Consequently,AmerenIllinois'2016electric deliveryservicerevenueswillbebasedonits2016 actualrecoverablecosts,ratebase,andreturnon commonequityascalculatedundertheIEIMA's performance-basedformularatemakingframework.

The2016revenuerequirementisexpectedtobehigher thanthe2015revenuerequirement,becauseofan expectedincreaseinrecoverablecosts,ratebase growth,andanexpectedincreaseinthemonthly averageyieldofUnitedStatesTreasurybonds.A 50basispointchangeintheaveragemonthlyyieldsof the30-yearUnitedStatesTreasurybondswouldresult inanestimated$6millionchangeinAmeren'sand AmerenIllinois'netincome,basedonits2016 projectedratebase.

InDecember2015,theICCissuedanorderwith respecttoAmerenIllinois'annualupdatefiling.TheICC approveda$106millionincreaseinAmerenIllinois' electricdeliveryservicerevenuerequirementbeginning inJanuary2016.Theserateshaveaffectedandwill continuetoaffectAmerenIllinois'cashreceiptsduring 2016,butwillnotbethesoledeterminantofitselectric deliveryserviceoperatingrevenues,whichwillinstead belargelydeterminedbytheIEIMA's2016revenue requirementreconciliation.The2016revenue requirementreconciliation,asdiscussedabove,is expectedtoresultinaregulatoryassetthatwillbe collectedfromcustomersin2018.

InDecember2015,theICCissuedarateorderthat approvedanincreaseinrevenuesforAmerenIllinois' naturalgasdeliveryserviceof$45million.Therevenue increasewasbasedona9.6%returnoncommon equity,acapitalstructurecomposedof50%common equity,andaratebaseof$1.2billion.Therateorder wasbasedona2016futuretestyear.Theratechanges wereineffectinJanuary2016.Inaddition,therate orderapprovedtheVBAforresidentialandsmall nonresidentialcustomersbeginningin2016.

AmerenMissouri'snextscheduledrefuelingand maintenanceoutageatitsCallawayenergycenterwill beinthespringof2016andAmerenMissouriexpects toincur$37millionofmaintenanceexpenses 58 in2016.Therewasnorefuelingoutagescheduledin2015;however,$9millioninpreparationcostswere incurredin2015forthe2016scheduledoutage.During the2014refueling,AmerenMissouriincurred maintenanceexpensesof$36million.Duringa scheduledoutage,whichoccursevery18months, maintenanceexpensesincreaserelativetonon-outage years.Additionally,dependingontheavailabilityofits othergenerationsourcesandthemarketpricesfor power,AmerenMissouri'spurchasedpowercostsmay increaseandtheamountofexcesspoweravailablefor salemaydecreaseversusnon-outageyears.Changes inpurchasedpowercostsandexcesspoweravailable forsaleareincludedintheFAC,whichresultsinlimited impactstoearnings.

AmerenMissouriwasengagedinlitigationwithan insurertorecoveranunpaidliabilityinsuranceclaimfor theDecember2005breachoftheupperreservoirat AmerenMissouri'sTaumSaukpumped-storage hydroelectricenergycenter.AsofDecember31,2015, AmerenMissourihadaninsurancereceivableof

$41million.InFebruary2016,AmerenMissouriand theinsurerreachedasettlementthatresultedin AmerenMissourireceiving$42millioninFebruary

2016.Aswecontinuetoexperiencecostincreasesandto makeinfrastructureinvestments,AmerenMissouriand AmerenIllinoisexpecttoseekregularelectricand naturalgasrateincreasesandtimelycostrecoveryand trackingmechanismsfromtheirregulators.Ameren MissouriandAmerenIllinoiswillalsoseek,as necessary,legislativesolutionstoaddressregulatory lagandtosupportinvestmentintheirutility infrastructureforthebenefitoftheircustomers, includingAmerenMissouri'scurrenteffortstoadvocate foralegislativesolutiontosupportNoranda's operations.Thesepressuresincludelimitedeconomic growthintheirserviceterritories,customer conservationefforts,theimpactsofadditional customerenergyefficiencyprograms,increased customeruseofinnovativeandincreasinglycost-effectivetechnologicaladvancesincludingdistributed generationandstorage,increasedinvestmentsand expectedfutureinvestmentsforenvironmental compliance,systemreliabilityimprovements,andnew generationcapacity,includingrenewableenergy requirements.Increasedinvestmentsalsoresultin higherdepreciationandfinancingcosts.Increased costsarealsoexpectedfromrisingemployeebenefit costsandhigherpropertyandincometaxes,among othercosts.Foradditionalinformationregardingrecentrateordersandrelatedappeals,Noranda,AmerenMissouri'sMEEIA plans,FERCreturnonequitycomplaintcases,andother pendingrequestsfiledwithstateandfederalregulatory commissions,seeNote2-RateandRegulatoryMatters, andNote10-CallawayEnergyCenter,underPartII, Item8,ofthisreport.LiquidityandCapitalResources Weexpecttoincursignificantcapitalexpendituresin ordertomakeinvestmentstoimproveourelectricand naturalgasutilityinfrastructureandtocomplywith existingenvironmentalregulations.Weestimatethatwe willincurupto$11.5billion(AmerenMissouri-upto

$4.3billion;AmerenIllinois-upto$6.2billion;ATXI-upto$1.0billion)ofcapitalexpendituresduringthe periodfrom2016through2020,excludingtheimpact oftheCleanPowerPlan.

Environmentalregulations,includingthoserelatedto

CO 2emissions,orotheractionstakenbytheEPAcouldresultinsignificantincreasesincapitalexpenditures andoperatingcosts.Thesecostscouldbeprohibitiveat someofAmerenMissouri'scoal-firedenergycenters.

AmerenMissouri'scapitalexpendituresaresubjectto MoPSCprudencereviews,whichcouldresultincost disallowancesaswellasregulatorylag.Thecostof AmerenIllinois'purchasedpowerandgaspurchased forresalecouldincrease.However,AmerenIllinois expectsthesecostswouldberecoveredfrom customerswithnomaterialadverseeffectonitsresults ofoperations,financialposition,orliquidity.Ameren's andAmerenMissouri'searningscouldbenefitfrom increasedinvestmenttocomplywithenvironmental regulationsifthoseinvestmentsarereflectedand recoveredonatimelybasisinrateschargedto

customers.

AmerenisevaluatingtheCleanPowerPlan'spotential impactstoitsoperations,includingthoserelatedto electricsystemreliability,anditslevelofinvestmentin customerenergyefficiencyprograms,renewableenergy, andotherformsofgenerationinvestment.InFebruary 2016,theUnitedStatesSupremeCourtstayedtheClean PowerPlanandallimplementationrequirementsuntil suchtimeaslegalappealsareconcluded.Appealsarenot expectedtoconcludepriorto2018.Iftheruleisultimately upheldandimplementedinsubstantiallysimilarformto therulewhenissued,AmerenMissouriexpectstoincur increasednetfuelandoperatingcosts,andmakenewor acceleratedcapitalexpenditures,inadditiontothecosts ofmakingmodificationstoexistingoperationsinorderto achievecompliance.Compliancemeasurescouldresultin theclosureoralterationoftheoperationofsomeof AmerenMissouri'scoalandnatural-gas-firedenergy centers,whichcouldresultinincreasedoperatingcosts.

AmerenMissourifilesanonbindingintegratedresource planwiththeMoPSCeverythreeyears.Ameren Missouri'sintegratedresourceplanfiledwiththeMoPSC inOctober2014,priortotheissuanceoftheCleanPower Plan,wasa20-yearplanthatsupportedamorefuel-diverseenergyportfolioinMissouri,includingcoal,solar, wind,naturalgas,andnuclearpower.Theplaninvolves expandingrenewablegeneration,retiringcoal-fired generationasenergycentersreachtheendoftheiruseful lives,continuationandexpansionofthethen-existing energyefficiencyprograms,andaddingnatural-gas-fired combinedcyclegeneration.

59 TheAmerenCompanieshavemultiyearcreditagreementsthatcumulativelyprovide$2.1billionof creditthroughDecember2019,subjecttoa364-day repaymentterminthecaseofAmerenMissouriand AmerenIllinois.SeeNote4-Short-termDebtand LiquidityunderPartII,Item8,ofthisreportfor additionalinformationregardingtheCreditAgreements.

Ameren,AmerenMissouri,andAmerenIllinoisbelieve thattheirliquidityisadequategiventheirexpected operatingcashflows,capitalexpenditures,andrelated financingplans.However,therecanbenoassurance thatsignificantchangesineconomicconditions, disruptionsinthecapitalandcreditmarkets,orother unforeseeneventswillnotmateriallyaffecttheirability toexecutetheirexpectedoperating,capital,or financingplans.

InNovember2015,Ameren(parent)issued

$350millionof2.70%seniorunsecurednotesdue November15,2020and$350millionof3.65%senior unsecurednotesdueFebruary15,2026.Amerenused theproceedstopayaportionofshort-termdebt consistingofcommercialpaperissuances.Ameren expectstoincurinterestchargesof$22million annuallyrelatedtotheseissuances.

InDecember2015,afederaltaxlawwasenactedthat authorizedthecontinueduseofbonusdepreciationthat allowsforanaccelerationofdeductionsfortax purposesatarateof50%for2015,2016,and2017.

Theratewillbereducedto40%in2018andthento 30%in2019.Bonusdepreciationwillbephasedoutin 2020unlessanewlawisenacted.Bonusdepreciation isexpectedtoincreasecashflowthroughatleast2020.

Amerenexpectstousethisincrementalcashflowto makecapitalinvestmentsinutilityinfrastructureforthe benefitofitscustomers.Withouttheseinvestments, bonusdepreciationwouldreduceratebase,which reducesourrevenuerequirementsandfutureearnings growth.TheimpactofbonusdepreciationonAmeren Missouri,AmerenIllinois,andATXIwillvarybasedon investmentlevelsateachcompany.

AsofDecember31,2015,Amerenhad$453millionin taxbenefitsfromfederalandstatenetoperatingloss carryforwards(AmerenMissouri-$39millionand AmerenIllinois-$131million)and$144millionin federalandstateincometaxcreditcarryforwards (AmerenMissouri-$26millionandAmerenIllinois-

$2million).Inaddition,Amerenhas$37millionof expectedstateincometaxrefundsandstate overpayments.Consistentwiththetaxallocation agreementbetweenAmerenanditssubsidiaries,thesecarryforwardsareexpectedtopartiallyoffsetincome taxliabilitiesforAmerenMissouriuntil2019and AmerenIllinoisuntil2021.Amerendoesnotexpectto makematerialfederalincometaxpaymentsuntil2021.

Thesetaxbenefits,primarilyattheAmeren(parent) level,whenrealized,wouldbeavailabletofundATXI transmissioninvestments.

Amerenexpectsitscashusedforcapitalexpenditures anddividendstoexceedcashprovidedbyoperating activitiesoverthenextseveralyears.Amerenexpects tousedebttofundsuchcashshortfalls;itdoesnot currentlyexpecttoissueequityoverthenextseveral

years.InOctober2015,Ameren'sboardofdirectorsdeclared afourthquarterdividendof42.5centspercommon share,a3.7%increasefromthepriorquarterly dividendrateof41centspershare,resultinginan annualizedequivalentdividendrateof$1.70pershare.

Theuseofcashfromoperatingactivitiesandfrom short-termborrowingstofundcapitalexpendituresand otherlong-terminvestmentsmayperiodicallyresultin aworkingcapitaldeficit,definedbycurrentliabilities exceedingcurrentassets,aswasthecaseat December31,2015,forAmeren.Theworkingcapital deficitasofDecember31,2015,wasprimarilythe resultofcurrentmaturitiesoflong-termdebtand commercialpaperissuances.TheAmerenCompanies had$301millionofcommercialpaperissuances outstandingasofDecember31,2015.WiththeCredit Agreementsandcashandcashequivalentsavailable, theAmerenCompanieshadaccessto$1.8billionof creditcapacityavailable,and$2.1billionofliquidityat December31,2015.

InFebruary2016,$260millionprincipalamountof AmerenMissouri's5.40%seniorsecurednotes maturedandwererepaidusingavailablecashand commercialpaperborrowings.Theaboveitemscouldhaveamaterialimpactonourresultsofoperations,financialposition,orliquidity.

Additionally,intheordinarycourseofbusiness,weevaluate strategiestoenhanceourresultsofoperations,financial position,orliquidity.Thesestrategiesmayinclude acquisitions,divestitures,andopportunitiestoreducecosts orincreaserevenues,andotherstrategicinitiativesto increaseAmeren'sshareholdervalue.Weareunableto predictwhich,ifany,oftheseinitiativeswillbeexecuted.

Theexecutionoftheseinitiativesmayhaveamaterial impactonourfutureresultsofoperations,financial position,orliquidity.REGULATORYMATTERSSeeNote2-RateandRegulatoryMattersunderPartII,Item8,ofthisreport.ACCOUNTINGMATTERSCriticalAccountingEstimatesPreparationofthefinancialstatementsandrelateddisclosuresincompliancewithGAAPrequirestheapplicationofappropriatetechnicalaccountingrulesandguidance,aswellastheuseofestimates.Theseestimatesinvolvejudgmentsregardingmanyfactorsthatinandofthemselvescouldmateriallyaffectthefinancialstatementsanddisclosures.Wehave 60 outlinedbelowthecriticalaccountingestimatesthatwebelievearethemostdifficult,subjective,orcomplex.Anychangeintheassumptionsorjudgmentsappliedindeterminingthefollowingmatters,amongothers,couldhaveamaterialimpacton futurefinancialresults.AccountingEstimateUncertaintiesAffectingApplicationRegulatoryMechanismsandCostRecoveryWedefercostsandrecognizerevenueinaccordancewith authoritativeaccountingguidance,andmakeinvestments thatweassumewillbecollectedinfuturerates.

Regulatoryenvironmentandexternalregulatory decisionsandrequirements Anticipatedfutureregulatorydecisionsandour assessmentoftheirimpact Theimpactofprudencereviews,complaintcases,and oppositionduringtheratemakingprocessthatmay limitourabilitytotimelyrecovercostsandearnafair returnonourinvestments AmerenIllinois'assessmentofandabilitytoestimate thecurrentyear'selectricdeliveryservicecoststobe reflectedinrevenuesandrecoveredfromcustomersin asubsequentyearundertheIEIMAperformance-based formularatemakingprocess AmerenIllinois'andATXI'sassessmentofandabilityto estimatethecurrentyear'selectrictransmissionservice coststobereflectedinrevenuesandrecoveredfrom customersinasubsequentyearundertheFERC ratemakingprocess AmerenMissouri'sestimateofrevenuerecoveryunder theMEEIABasisforJudgment Wedeterminewhichcostsarerecoverablebyreviewingpreviousrulingsbyregulatoryauthoritiesinjurisdictionswherewe operateandanyotherfactorsthatmayindicatewhethercostrecoveryisprobable.Iffactsandcircumstancesleadusto concludethatarecordedregulatoryassetisnolongerprobableofrecoveryorthatplantassetsareprobableofdisallowance, werecordachargetoearnings,whichcouldbematerial.AmerenIllinoisestimatesitsannualrevenuerequirementpursuant totheIEIMAforinterimperiodsbyusinginternalforecastedinformation,suchasprojectedoperationsandmaintenance expenses,depreciationexpense,taxesotherthanincometaxes,andratebase,aswellaspublishedforecasteddataregarding thatyear'smonthlyaverageyieldsofthe30-yearUnitedStatesTreasurybonds.AmerenIllinoisestimatesitsannualrevenue requirementasofDecember31ofeachyearusingthatyear'sactualoperatingresultsandassessestheprobabilityof recoveryfromorrefundtocustomersthattheICCwillorderattheendofthefollowingyear.Variationsincostsincurred, investmentsmade,orordersbytheICCorcourtscanresultinasubsequentchangeinAmerenIllinois'estimate.Ameren IllinoisandATXIfollowasimilarprocessfortheirFERCrate-regulatedelectrictransmissionbusinesses.AmerenMissouri estimateslostrevenuesresultingfromitsMEEIAcustomerenergyefficiencyprograms.AmerenMissouriusesaMEEIArider tocollectfromorrefundtocustomersanyannualdifferenceintheactualamountsincurredandtheamountscollectedfrom customers.SeeNote2-RateandRegulatoryMattersunderPartII,Item8,ofthisreportforquantificationoftheseassetsor liabilitiesforeachoftheAmerenCompanies.SeeNote1-SummaryofSignificantAccountingPoliciesunderPartII,Item8, ofthisreportforalistingofregulatorymechanismsusedbyAmerenMissouriandAmerenIllinois.BenefitPlanAccountingBasedonactuarialcalculations,weaccruecostsof providingfutureemployeebenefitsinaccordancewith authoritativeaccountingguidanceregardingbenefitplans.

SeeNote11-RetirementBenefitsunderPartII,Item8, ofthisreport.

Futurerateofreturnonpensionandotherplanassets Valuationinputsandassumptionsusedinthefairvalue measurementsofplanassets,excludingthoseinputs thatarereadilyobservable Discountrates Healthcarecosttrendrates Timingofemployeeretirementsandmortality

assumptions Abilitytorecovercertainbenefitplancostsfromour

customersChangingmarketconditionsthatmayaffectinvestment andinterestrateenvironments 61 AccountingEstimateUncertaintiesAffectingApplicationBasisforJudgmentOurultimateselectionofthediscountrate,healthcaretrendrate,andexpectedrateofreturnonpensionandother postretirementbenefitplanassetsisbasedonourconsistentapplicationofassumption-settingmethodologiesandour reviewofavailablehistorical,current,andprojectedrates,asapplicable.Wealsomakemortalityassumptionstoestimateour pensionandotherpostretirementbenefitobligations.SeeNote11-RetirementBenefitsunderPartII,Item8,ofthisreport forsensitivityofAmeren'sbenefitplanstopotentialchangesintheseassumptions.AccountingforContingenciesWemakejudgmentsandestimatesintherecordingand thedisclosingofliabilitiesforclaims,litigation, environmentalremediation,theactionsofvarious regulatoryagencies,orothermattersthatoccurinthe normalcourseofbusiness.Werecordalosscontingency whenitisprobablethataliabilityhasbeenincurredand thattheamountofthelosscanbereasonablyestimated.

Estimatingfinancialimpactofevents Estimatinglikelihoodofvariouspotentialoutcomes Regulatoryandpoliticalenvironmentsandrequirements Outcomeoflegalproceedings,settlements,orother

factorsChangesinregulation,expectedscopeofwork, technologyortimingofenvironmentalremediationBasisforJudgment Thedeterminationofalosscontingencyrequiressignificantjudgmentastotheexpectedoutcomeofthecontingencyinfuture periods.Inmakingthedeterminationastotheamountofpotentiallossandtheprobabilityofloss,weconsiderallavailable evidence,includingtheexpectedoutcomeofpotentiallitigation.Ifnoestimateisbetterthananotherwithinourrangeof estimates,werecordasourbestestimateofalosstheminimumvalueofourestimatedrangeofoutcomes.Asadditionalinformationbecomesavailable,wereassessthepotentialliabilityrelatedtothecontingencyandreviseourestimates.Inourevaluationoflegalmatters,managementconsultswithlegalcounselandreliesonanalysisofrelevantcaselawandlegal precedents.SeeNote2-RateandRegulatoryMatters,Note10-CallawayEnergyCenterandNote15-Commitmentsand ContingenciesunderPartII,Item8,ofthisreportforinformationontheAmerenCompanies'contingencies.AccountingforIncomeTaxesFollowingauthoritativeaccountingguidance,werecord theprovisionforincometaxes,deferredtaxassetsand liabilities,andavaluationallowanceagainstnetdeferred taxassets,ifany.SeeNote13-IncomeTaxesunder PartII,Item8,ofthisreport.

Changesinbusiness,industry,laws,technology,or economicandmarketconditionsaffectingforecasted financialconditionand/orresultsofoperations Estimatesoftheamountandcharacteroffuturetaxable

incomeEnactedtaxratesapplicabletotaxableincomeinyears inwhichtemporarydifferencesarerecoveredorsettled Effectivenessofimplementingtaxplanningstrategies Changesinincometaxlaws ResultsofauditsandexaminationsbytaxingauthoritiesBasisforJudgment Thereportingoftax-relatedassetsandliabilitiesrequirestheuseofestimatesandsignificantmanagementjudgment.

Deferredtaxassetsandliabilitiesarerecordedtorepresentfutureeffectsonincometaxesfortemporarydifferencesbetweenthebasisofassetsforfinancialreportingandtaxpurposes.Althoughmanagementbelievesthatcurrentestimatesfor deferredtaxassetsandliabilitiesarereasonable,actualresultscoulddifferfromtheseestimatesforavarietyofreasons, includingachangeinforecastedfinancialconditionand/orresultsofoperations,changeinincometaxlawsorenactedtax rates,theform,structure,andtimingofassetorstocksalesordispositions,andresultsofauditsandexaminationsbytaxingauthorities.Valuationallowancesagainstdeferredtaxassetsarerecordedwhenmanagementconcludesitismorelikelythan notsuchassetwillnotberealizedinfutureperiods.Accountingforincometaxesalsorequiresthatonlytaxbenefitsfor positionstakenorexpectedtobetakenontaxreturnsthatmeetthemore-likely-than-notrecognitionthresholdcanbe recognizedorcontinuetoberecognized.Managementevaluateseachpositionsolelyonthetechnicalmeritsandfactsand circumstancesoftheposition,assumingthatthepositionwillbeexaminedbyataxingauthoritythathasfullknowledgeofall relevantinformation.Significantjudgmentisrequiredtodeterminerecognitionthresholdsandtherelatedamountoftaxbenefitstoberecognized.Ateachperiod-end,andasnewdevelopmentsoccur,managementreevaluatesitstaxpositions.

SeeNote13-IncomeTaxesunderPartII,Item8,ofthisreportfortheamountofdeferredtaxassetsanduncertaintax positionsrecordedatDecember31,2015.

62 UnbilledRevenueAttheendofeachperiod,Ameren,AmerenMissouri,andAmerenIllinoisestimatetheusagethathasbeenprovidedto customersbutnotyetbilled.Thisusageamount,alongwith aperunitprice,isusedtoestimateanunbilledbalance.

Estimatingcustomerenergyusage Estimatingimpactsofweatherandotherusage-affectingfactorsfortheunbilledperiod Estimatinglossofenergyduringtransmissionand

deliveryBasisforJudgment Webaseourestimateofunbilledrevenueeachperiodonthevolumeofenergydelivered,asvaluedbyamodelofbilling cyclesandhistoricalusageratesandgrowthorcontractionbycustomerclassforourservicearea.Thisfigureisthen adjustedforthemodeledimpactofseasonalandweathervariationsbasedonhistoricalresults.Seethebalancesheetfor eachoftheAmerenCompaniesunderPartII,Item8,ofthisreportforunbilledrevenueamounts.ImpactofNewAccountingPronouncementsSeeNote1-SummaryofSignificantAccountingPoliciesunderPartII,Item8,ofthisreport.EFFECTSOFINFLATIONANDCHANGINGPRICESAmeren'sratesforretailelectricandnaturalgasutilityserviceareregulatedbytheMoPSCandtheICC.Nonretail electricratesareregulatedbytheFERC.Rateregulationis generallybasedontherecoveryofhistoricalorprojected costs.Asaresult,revenueincreasescouldlagbehind changingprices.AmerenIllinoisparticipatesinthe performance-basedformularatemakingprocesspursuant totheIEIMAforitselectricdeliveryservicebusiness.

AmerenIllinoisisrequiredtopurchaseallofitspower throughprocurementprocessesadministeredbytheIPA.

Thecostofprocuredpowercanbeaffectedbyinflation.

WithintheIEIMAformula,themonthlyaverageyieldsof30-yearUnitedStatesTreasurybondsarethebasisforAmeren Illinois'returnonequity.Therefore,thereisadirect correlationbetweentheyieldofUnitedStatesTreasury bonds,whichareaffectedbyinflation,andtheearningsof AmerenIllinois'electricdistributionbusiness.Ameren IllinoisandATXIuseacompany-specific,forward-looking rateformulaframeworkinsettingtheirtransmissionrates.

Theseforward-lookingratesareupdatedeachJanuarywith forecastedinformation.Areconciliationduringtheyear, whichadjustsfortheactualrevenuerequirementandactual salesvolumes,isusedtoadjustbillingratesina subsequentyear.Thecurrentreplacementcostofourutilityplantsubstantiallyexceedsourrecordedhistoricalcost.Underexistingregulatorypractice,onlythehistoricalcostofplant isrecoverablefromcustomers.Asaresult,customerrates designedtoproviderecoveryofhistoricalcoststhrough depreciationmightnotbeadequatetoreplaceplantin futureyears.AmerenMissourirecoversthecostoffuelforelectricgenerationandthecostofpurchasedpowerbyadjusting ratesasallowedthroughtheFAC.TheApril2015MoPSC electricrateorderapprovedAmerenMissouri'srequestfor continueduseoftheFAC;however,itchangedtheFACto excludealltransmissionrevenuesandsubstantiallyall transmissioncharges.Assuch,AmerenMissouriis exposedtotransmissionchargestotheextenttheyexceed transmissionrevenues.AmerenIllinoisrecoverspower supplycostsfromelectriccustomersbyadjustingrates througharidermechanismtoaccommodatechangesin powerprices.InourMissouriandIllinoisretailnaturalgasutilityjurisdictions,changesinnaturalgascostsaregenerally reflectedinbillingstonaturalgascustomersthroughPGA

clauses.SeePartI,Item1,andNote2-RateandRegulatoryMattersunderPartII,Item8,ofthisreportforadditional informationonourcostrecoverymechanisms.ITEM7A.QUANTITATIVEANDQUALITATIVEDISCLOSURESABOUTMARKETRISKMarketriskistheriskofchangesinvalueofaphysicalassetorafinancialinstrument,derivativeornonderivative, causedbyfluctuationsinmarketvariablessuchasinterest rates,commodityprices,andequitysecurityprices.A derivativeisacontractwhosevalueisdependenton,or derivedfrom,thevalueofsomeunderlyingassetorindex.

Thefollowingdiscussionofourriskmanagementactivities includesforward-lookingstatementsthatinvolverisksand uncertainties.Actualresultscoulddiffermateriallyfrom thoseprojectedintheforward-lookingstatements.We handlemarketrisksinaccordancewithestablishedpolicies,whichmayincludeenteringintovariousderivative transactions.Inthenormalcourseofbusiness,wealsoface risksthatareeithernonfinancialornonquantifiable.Such risks,principallybusiness,legal,andoperationalrisks,are notpartofthefollowingdiscussion.Ourriskmanagementobjectivesaretooptimizeourphysicalgeneratingassetsandtopursuemarket opportunitieswithinprudentriskparameters.Ourrisk managementpoliciesaresetbyariskmanagementsteering committee,whichiscomposedofsenior-levelAmeren officers,withAmerenboardofdirectorsoversight.

63AccountingEstimateUncertaintiesAffectingApplication InterestRateRiskWeareexposedtomarketriskthroughchangesininterestratesassociatedwith:

long-termandshort-termvariable-ratedebt; fixed-ratedebt; UnitedStatesTreasurybonds;and definedpensionandpostretirementbenefitplans.Wemanageourinterestrateexposurebycontrollingtheamountofdebtinstrumentswithinourtotalcapitalizationportfolioandbymonitoringtheeffectsof marketchangesoninterestrates.Fordefinedpensionand postretirementbenefitplans,wecontrolthedurationand theportfoliomixofourplanassets.Thefollowingtablepresentstheestimatedincreaseinourannualinterestexpenseanddecreaseinnetincomeif interestratesweretoincreaseby1%onvariable-ratedebt outstandingatDecember31,2015:InterestExpenseNetIncome (a)Ameren..................$5$(3)AmerenMissouri..........2(1)AmerenIllinois

............(b)(b)(a)Calculationsarebasedonanestimatedtaxrateof38%,37%,and37%forAmeren,AmerenMissouri,andAmerenIllinois, respectively.(b)Lessthan$1million.AmerenIllinois'annualreturnonequityundertheformularatemakingprocessforitselectricdistributionbusinessisdirectlycorrelatedtotheaveragemonthlyyields of30-yearUnitedStatesTreasurybondsplus580basis pointsforacalendaryear.Theyieldsonsuchbondsare outsideofAmerenIllinois'control.A50basispointchange intheaveragemonthlyyieldsofthe30-yearUnitedStates Treasurybondswouldresultinanestimated$6million changeinAmeren'sandAmerenIllinois'netincome,based onits2016projectedratebase.CreditRiskCreditriskrepresentsthelossthatwouldberecognizedifcounterpartiesshouldfailtoperformascontracted.Exchange-tradedcontractsaresupportedbythe financialandcreditqualityoftheclearingmembersofthe respectiveexchangesandcarryonlyanominalcreditrisk.

Inallothertransactions,weareexposedtocreditriskinthe eventofnonperformancebythecounterpartiestothe transaction.SeeNote7-DerivativeFinancialInstruments underPartII,Item8,ofthisreportforinformationonthe potentiallossoncounterpartyexposureasofDecember31, 2015.Ourrevenuesareprimarilyderivedfromsalesordeliveryofelectricityandnaturalgastocustomersin MissouriandIllinois.Ourphysicalandfinancialinstruments aresubjecttocreditriskconsistingoftradeaccounts receivablesandexecutorycontractswithmarketrisk exposures.Theriskassociatedwithtradereceivablesismitigatedbythelargenumberofcustomersinabroad rangeofindustrygroupswhomakeupourcustomerbase.

AtDecember31,2015,nononaffiliatedcustomer representedmorethan10%,intheaggregate,ofour accountsreceivable.Additionally,AmerenIllinoisfacesrisks associatedwiththepurchaseofreceivables.TheIllinois PublicUtilitiesActrequiresAmerenIllinoistoestablish electricutilityconsolidatedbillingandpurchaseof receivablesservices.Attheoptionofanalternativeretail electricsupplier,AmerenIllinoismayberequiredto purchasethesupplier'sreceivablesrelatingtoAmeren Illinois'deliveryservicecustomerswhoelectedtoreceive powersupplyfromthealternativeretailelectricsupplier.

Whenthatoptionisselected,AmerenIllinoisproduces consolidatedbillsfortheapplicableretailcustomers reflectingchargesforelectricdeliveryserviceand purchasedreceivables.AsofDecember31,2015,Ameren Illinois'balanceofpurchasedaccountsreceivable associatedwiththeutilityconsolidatedbillingandpurchase ofreceivablesserviceswas$25million.Theriskassociated withAmerenIllinois'electricandnaturalgastrade receivablesisalsomitigatedbyarateadjustment mechanismthatallowsAmerenIllinoistorecoverthe differencebetweenitsactualnetbaddebtwrite-offsunder GAAPandtheamountofnetbaddebtwrite-offsincludedin itsbaserates.AmerenMissouriandAmerenIllinois continuetomonitortheimpactofincreasingrateson customercollections.AmerenMissouriandAmerenIllinois makeadjustmentstotheirrespectiveallowancefordoubtful accountsasdeemednecessarytoensurethatsuch allowancesareadequatetocoverestimateduncollectible customeraccountbalances.EquityPriceRiskOurcostsforprovidingdefinedbenefitretirementandpostretirementbenefitplansaredependentuponanumberoffactors,includingtherateofreturnonplanassets.

Amerenmanagesplanassetsinaccordancewiththe "prudentinvestor"guidelinescontainedinERISA.Ameren's goalistoensurethatsufficientfundsareavailableto providebenefitsatthetimetheyarepayable,whilealso maximizingtotalreturnonplanassetsandminimizing expensevolatilityconsistentwithitstoleranceforrisk.

Amerendelegatesinvestmentmanagementtospecialists.

Whereappropriate,Amerenprovidestheinvestment managerwithguidelinesthatspecifyallowableand prohibitedinvestmenttypes.Amerenregularlymonitors managerperformanceandcompliancewithinvestment

guidelines.Theexpectedreturnonplanassetsassumptionisbasedonhistoricalandprojectedratesofreturnforcurrent andplannedassetclassesintheinvestmentportfolio.

Projectedratesofreturnforeachassetclassareestimated afterananalysisofhistoricalexperience,future expectations,andthevolatilityofthevariousassetclasses.

Afterconsideringthetargetassetallocationforeachasset class,weadjusttheoverallexpectedrateofreturnforthe portfolioforhistoricalandexpectedexperienceofactive 64 portfoliomanagementresultscomparedwithbenchmarkreturns,andfortheeffectofexpensespaidfromplan assets.Contributionstotheplansandfuturecostscould increasemateriallyifwedonotachievepensionand postretirementassetportfolioinvestmentreturnsequalto orinexcessofour2016assumedreturnonplanassetsof

7.00%.AmerenMissourialsomaintainsatrustfund,asrequiredbytheNRCandMissourilaw,tofundcertaincosts ofnuclearplantdecommissioning.AsofDecember31, 2015,thisfundwasinvestedindomesticequitysecurities (66%)anddebtsecurities(34%).Bymaintainingaportfolio thatincludeslong-termequityinvestments,Ameren Missouriseekstomaximizethereturnstobeusedtofund nucleardecommissioningcostswithinacceptable parametersofrisk.However,theequitysecuritiesincluded intheportfolioareexposedtopricefluctuationsinequity markets.Thedebtsecuritiesareexposedtochangesin interestrates.AmerenMissouriactivelymonitorsthe portfoliobybenchmarkingtheperformanceofits investmentsagainstcertainindicesandbymaintainingand periodicallyreviewingestablishedtargetallocation percentagesofthetrustassetstovariousinvestment options.AmerenMissouri'sexposuretoequitypricemarket riskisinlargepartmitigatedbecauseAmerenMissouriis currentlyallowedtorecoveritsdecommissioningcosts, whichwouldincludeunfavorableinvestmentresults, throughelectricrates.Additionally,Amerenhascompany-ownedlifeinsurancecontractsthatareusedtosupportAmeren's deferredcompensationplans.Theselifeinsurancecontracts includeequityanddebtinvestmentsthatareexposedto pricefluctuationsinequitymarketsandtochangesin interestrates.CommodityPriceRiskWithregardtoAmerenMissouri'sandAmerenIllinois'electricandnaturalgasdistributionbusinesses,exposuretochangingmarketpricesisinlargepartmitigatedbythefact thattherearecostrecoverymechanismsinplace.These costrecoverymechanismsallowAmerenMissouriand AmerenIllinoistopassontoretailcustomersprudently incurredcostsforfuel,purchasedpower,andnaturalgas

supply.AmerenMissouri'sandAmerenIllinois'strategyisdesignedtoreducetheeffectofmarketfluctuationsfortheir regulatedcustomers.Theeffectsofpricevolatilitycannot beeliminated.However,procurementandsalesstrategies involveriskmanagementtechniquesandinstruments,as wellasthemanagementofphysicalassets.AmerenMissourihasaFAC,afuelandpurchasedpowercostrecoverymechanismthatallowsittorecoveror refundthroughcustomerrates95%ofchangesinnet energycostsgreaterorlessthantheamountsetinbase rateswithoutatraditionalrateproceeding,subjectto MoPSCprudencereviews.AmerenMissouriremains exposedtotheremaining5%ofsuchchanges.AmerenIllinoishasacostrecoverymechanismforpowerpurchasedonbehalfofitscustomers.Ameren Illinoisisrequiredtoserveastheprovideroflastresortfor electriccustomersinitsserviceterritorywhohavenot chosenanalternativeretailelectricsupplier.AmerenIllinois doesnotgenerateearningsbasedontheresaleofpower butratheronthedeliveryofenergy.AmerenIllinois purchasespowerprimarilythroughMISO,withadditional procurementeventsadministeredbytheIPA.TheIPAhas proposedandtheICChasapprovedmultipleprocurement eventscoveringportionsofyearsthrough2018.In2015, actinginitsroleasprovideroflastresort,AmerenIllinois suppliedapproximately26%ofitskilowatthoursalestoits electriccustomers.AmerenIllinoisexpectsfullrecoveryof itspurchasedpowercosts.AmerenMissouriandAmerenIllinoishavePGAclausesthatpermitcostsincurredfornaturalgastobe recovereddirectlyfromutilitycustomerswithouta traditionalrateproceeding,subjecttoprudencereview.Withregardtoourexposureforcommoditypriceriskforconstructionandmaintenanceactivities,Amerenis exposedtochangesinmarketpricesformetalcommodities andtolaboravailability.SeeTransmissionandSupplyofElectricPowerunderPartI,Item1,ofthisreportforthepercentagesofour historicalneedssatisfiedbycoal,nuclear,naturalgas,oil, andrenewables.AlsoseeNote15-Commitmentsand ContingenciesunderPartII,Item8,ofthisreportfor additionalinformation.CommoditySupplierRiskTheuseofultra-low-sulfurcoalispartofAmerenMissouri'senvironmentalcompliancestrategy.AmerenMissourihasamultiyearagreementtopurchaseultra-low-sulfurcoalthrough2018tocomplywithenvironmental regulations.Thecoalcontractiswithasinglesupplier.

Disruptionstothedeliveriesofthatultra-low-sulfurcoal fromthesuppliercouldcompromiseAmerenMissouri's abilitytooperateincompliancewithemissionstandards.

Othersourcesofultra-low-sulfurcoalarelimited,andthe constructionofpollutioncontrolequipmentrequires significantleadtime.IfAmerenMissouriweretoexperience atemporarydisruptionofultra-low-sulfurcoaldeliveries thatcausedittoexhaustitsexistinginventory,andifother sourcesofultra-low-sulfurcoalwerenotavailable,Ameren Missouriwoulduseitsexistingemissionallowancesor purchaseemissionallowancestoachievecompliancewith environmentalregulations.Currently,theCallawayenergycenterusesnuclearfuelassembliesofadesignfabricatedbyonlyasinglesupplier.

ThatsupplieriscurrentlytheonlyNRC-licensedsupplier abletoprovidefuelassembliestotheCallawayenergy center.IfAmerenMissourishoulddecidetochangefuel suppliersortochangethetypeoffuelassemblydesignthat iscurrentlylicensedforuseattheCallawayenergycenter, uptothreeyearsofanalysisandlicensingeffortwouldbe requiredtofullyimplementsuchachange.

65 FairValueofContractsWeusederivativesprincipallytomanagetheriskofchangesinmarketpricesfornaturalgas,power,anduranium,aswellastheriskofchangesinrailtransportationsurchargesthroughfueloilhedges.Thefollowingtablepresentsthefavorable(unfavorable)changesinthefairvalueofallderivativecontractsmarked-to-marketduringtheyearendedDecember31,2015.

Weusevariousmethodstodeterminethefairvalueofourcontracts.Inaccordancewithauthoritativeaccountingguidancefor fairvaluehierarchylevels,thesourcesweusedtodeterminethefairvalueofthesecontractswereactivequotes(Level1),

inputscorroboratedbymarketdata(Level2),andothermodelingandvaluationmethodsthatarenotcorroboratedbymarket data(Level3).SeeNote8-FairValueMeasurementsunderPartII,Item8,ofthisreportforadditionalinformationregarding themethodsusedtodeterminethefairvalueofthesecontracts.

Ameren Missouri AmerenIllinoisAmerenFairvalueofcontractsatbeginningofyear,net..................................................$(28)$(185)$(213)Contractsrealizedorotherwisesettledduringtheperiod...........................................154156Fairvalueofnewcontractsenteredintoduringtheperiod..........................................6(19)(13)Otherchangesinfairvalue

..................................................................(20)(56)(76)Fairvalueofcontractsoutstandingatendofyear,net.............................................$(27)$(219)$(246)ThefollowingtablepresentsmaturitiesofderivativecontractsasofDecember31,2015,bythehierarchylevelsusedtodeterminethefairvalueofthecontracts:SourcesofFairValue MaturityLessThan1Year Maturity1-3Years Maturity3-5YearsMaturityinExcessof5Years TotalFairValueAmerenMissouri:Level1........................................................$(23)$(6)$-$-$(29)Level2 (a)......................................................(5)(6)(2)-

(13)Level3 (b)......................................................15---15 Total.........................................................$(13)$(12)$(2)$-$(27)AmerenIllinois:

Level1........................................................$-$(1)$-$-$(1)Level2 (a)......................................................(31)(17)--(48)Level3 (b)......................................................(12)(24)(24)(110)(170)

Total.........................................................$(43)$(42)$(24)$(110)$(219)

Ameren:

Level1........................................................$(23)$(7)$-$-$(30)Level2 (a)......................................................(36)(23)(2)-(61)Level3 (b)......................................................3(24)(24)(110)(155)

Total.........................................................$(56)$(54)$(26)$(110)$(246)(a)Principallyfixed-pricevs.floatingover-the-counterpowerswaps,powerforwards,andfixed-pricevs.floatingover-the-counternaturalgas swaps.(b)Principallypowerforwardcontractvaluesbasedoninformationfromexternalsources,historicalresults,andourestimates.Level3alsoincludesoptioncontractvaluesbasedonanoptionvaluationmodel.

66 ITEM8.FINANCIALSTATEMENTSANDSUPPLEMENTARYDATAReportofIndependentRegisteredPublicAccountingFirm TotheBoardofDirectorsandShareholdersofAmerenCorporation:Inouropinion,theconsolidatedfinancialstatementslistedintheindexappearingunderItem15(a)(1)presentfairly,inallmaterialrespects,thefinancialpositionofAmerenCorporationanditssubsidiariesatDecember31,2015and2014,andtheresultsoftheiroperationsandtheircashflowsforeachofthethreeyearsintheperiodendedDecember31,2015,in conformitywithaccountingprinciplesgenerallyacceptedintheUnitedStatesofAmerica.Inaddition,inouropinion,the financialstatementscheduleslistedintheindexappearingunderItem15(a)(2)presentfairly,inallmaterialrespects,the informationsetforththereinwhenreadinconjunctionwiththerelatedconsolidatedfinancialstatements.Also,inouropinion, theCompanymaintained,inallmaterialrespects,effectiveinternalcontroloverfinancialreportingasofDecember31,2015, basedoncriteriaestablishedinInternalControl-IntegratedFramework(2013)issuedbytheCommitteeofSponsoringOrganizationsoftheTreadwayCommission(COSO).TheCompany'smanagementisresponsibleforthesefinancialstatementsandfinancialstatementschedules,formaintainingeffectiveinternalcontroloverfinancialreportingandforitsassessmentof theeffectivenessofinternalcontroloverfinancialreporting,includedinManagement'sReportonInternalControlover FinancialReportingappearingunderItem9A.Ourresponsibilityistoexpressopinionsonthesefinancialstatements,onthe financialstatementschedules,andontheCompany'sinternalcontroloverfinancialreportingbasedonourintegratedaudits.

WeconductedourauditsinaccordancewiththestandardsofthePublicCompanyAccountingOversightBoard(United States).Thosestandardsrequirethatweplanandperformtheauditstoobtainreasonableassuranceaboutwhetherthe financialstatementsarefreeofmaterialmisstatementandwhethereffectiveinternalcontroloverfinancialreportingwas maintainedinallmaterialrespects.Ourauditsofthefinancialstatementsincludedexamining,onatestbasis,evidence supportingtheamountsanddisclosuresinthefinancialstatements,assessingtheaccountingprinciplesusedandsignificant estimatesmadebymanagement,andevaluatingtheoverallfinancialstatementpresentation.Ourauditofinternalcontrolover financialreportingincludedobtaininganunderstandingofinternalcontroloverfinancialreporting,assessingtheriskthatamaterialweaknessexists,andtestingandevaluatingthedesignandoperatingeffectivenessofinternalcontrolbasedonthe assessedrisk.Ourauditsalsoincludedperformingsuchotherproceduresasweconsiderednecessaryinthecircumstances.

Webelievethatourauditsprovideareasonablebasisforouropinions.Acompany'sinternalcontroloverfinancialreportingisaprocessdesignedtoprovidereasonableassuranceregardingthereliabilityoffinancialreportingandthepreparationoffinancialstatementsforexternalpurposesinaccordancewithgenerally acceptedaccountingprinciples.Acompany'sinternalcontroloverfinancialreportingincludesthosepoliciesandprocedures that(i)pertaintothemaintenanceofrecordsthat,inreasonabledetail,accuratelyandfairlyreflectthetransactionsand dispositionsoftheassetsofthecompany;(ii)providereasonableassurancethattransactionsarerecordedasnecessaryto permitpreparationoffinancialstatementsinaccordancewithgenerallyacceptedaccountingprinciples,andthatreceiptsandexpendituresofthecompanyarebeingmadeonlyinaccordancewithauthorizationsofmanagementanddirectorsofthe company;and(iii)providereasonableassuranceregardingpreventionortimelydetectionofunauthorizedacquisition,use,or dispositionofthecompany'sassetsthatcouldhaveamaterialeffectonthefinancialstatements.Becauseofitsinherentlimitations,internalcontroloverfinancialreportingmaynotpreventordetectmisstatements.Also,projectionsofanyevaluationofeffectivenesstofutureperiodsaresubjecttotheriskthatcontrolsmaybecomeinadequate becauseofchangesinconditions,orthatthedegreeofcompliancewiththepoliciesorproceduresmaydeteriorate./s/PricewaterhouseCoopersLLP PricewaterhouseCoopersLLP St.Louis,Missouri February26,2016 67 ReportofIndependentRegisteredPublicAccountingFirmTotheBoardofDirectorsandShareholdersofUnionElectricCompany:Inouropinion,thefinancialstatementslistedintheindexappearingunderItem15(a)(1)presentfairly,inallmaterialrespects,thefinancialpositionofUnionElectricCompanyatDecember31,2015and2014,andtheresultsofitsoperationsanditscash flowsforeachofthethreeyearsintheperiodendedDecember31,2015,inconformitywithaccountingprinciplesgenerally acceptedintheUnitedStatesofAmerica.Inaddition,inouropinion,thefinancialstatementschedulelistedintheindex appearingunderItem15(a)(2)presentsfairly,inallmaterialrespects,theinformationsetforththereinwhenreadin conjunctionwiththerelatedfinancialstatements.Thesefinancialstatementsandfinancialstatementschedulearethe responsibilityoftheCompany'smanagement.Ourresponsibilityistoexpressanopiniononthesefinancialstatementsand financialstatementschedulebasedonouraudits.Weconductedourauditsofthesestatementsinaccordancewiththe standardsofthePublicCompanyAccountingOversightBoard(UnitedStates).Thosestandardsrequirethatweplanand performtheaudittoobtainreasonableassuranceaboutwhetherthefinancialstatementsarefreeofmaterialmisstatement.Anauditincludesexamining,onatestbasis,evidencesupportingtheamountsanddisclosuresinthefinancialstatements, assessingtheaccountingprinciplesusedandsignificantestimatesmadebymanagement,andevaluatingtheoverallfinancial statementpresentation.Webelievethatourauditsprovideareasonablebasisforouropinion./s/PricewaterhouseCoopersLLP PricewaterhouseCoopersLLP St.Louis,Missouri February26,2016ReportofIndependentRegisteredPublicAccountingFirmTotheBoardofDirectorsandShareholdersofAmerenIllinoisCompany:Inouropinion,thefinancialstatementslistedintheindexappearingunderItem15(a)(1)presentfairly,inallmaterialrespects,thefinancialpositionofAmerenIllinoisCompanyatDecember31,2015and2014,andtheresultsofitsoperationsandits cashflowsforeachofthethreeyearsintheperiodendedDecember31,2015,inconformitywithaccountingprinciples generallyacceptedintheUnitedStatesofAmerica.Inaddition,inouropinion,thefinancialstatementschedulelistedinthe indexappearingunderItem15(a)(2)presentsfairly,inallmaterialrespects,theinformationsetforththereinwhenreadin conjunctionwiththerelatedfinancialstatements.Thesefinancialstatementsandfinancialstatementschedulearethe responsibilityoftheCompany'smanagement.Ourresponsibilityistoexpressanopiniononthesefinancialstatementsand financialstatementschedulebasedonouraudits.Weconductedourauditsofthesestatementsinaccordancewiththe standardsofthePublicCompanyAccountingOversightBoard(UnitedStates).Thosestandardsrequirethatweplanand performtheaudittoobtainreasonableassuranceaboutwhetherthefinancialstatementsarefreeofmaterialmisstatement.Anauditincludesexamining,onatestbasis,evidencesupportingtheamountsanddisclosuresinthefinancialstatements, assessingtheaccountingprinciplesusedandsignificantestimatesmadebymanagement,andevaluatingtheoverallfinancial statementpresentation.Webelievethatourauditsprovideareasonablebasisforouropinion./s/PricewaterhouseCoopersLLP PricewaterhouseCoopersLLP St.Louis,Missouri February26,2016 68 AMERENCORPORATIONCONSOLIDATEDSTATEMENTOFINCOME(Inmillions,exceptpershareamounts)YearEndedDecember31, 2015 2014 2013OperatingRevenues:

Electric$5,180$4,913$4,832 Gas 9181,1401,006Totaloperatingrevenues 6,0986,0535,838OperatingExpenses:

Fuel 878826845Purchasedpower 514461508Gaspurchasedforresale 415615526Otheroperationsandmaintenance 1,6941,6841,611ProvisionforCallawayconstructionandoperatinglicense(Note2) 69--Depreciationandamortization 796745706Taxesotherthanincometaxes 473468458Totaloperatingexpenses 4,8394,7994,654OperatingIncome 1,2591,2541,184OtherIncomeandExpenses:Miscellaneousincome 747969Miscellaneousexpense 302226Totalotherincome 445743InterestCharges355341398IncomeBeforeIncomeTaxes 948970829IncomeTaxes 363377311IncomefromContinuingOperations 585593518Income(Loss)fromDiscontinuedOperations,NetofTaxes(Note16) 51(1)(223)NetIncome 636592295Less:NetIncomefromContinuingOperationsAttributabletoNoncontrolling Interests 6 66NetIncome(Loss)AttributabletoAmerenCommonShareholders:ContinuingOperations579587512DiscontinuedOperations51(1)(223)NetIncomeAttributabletoAmerenCommonShareholders$630$586$289Earnings(Loss)perCommonShare-Basic:ContinuingOperations$2.39$2.42$2.11DiscontinuedOperations0.21-(0.92)EarningsperCommonShare-Basic$2.60$2.42$1.19Earnings(Loss)perCommonShare-Diluted:ContinuingOperations$2.38$2.40$2.10DiscontinuedOperations0.21-(0.92)EarningsperCommonShare-Diluted$2.59$2.40$1.18DividendsperCommonShare$1.655$1.610$1.600AverageCommonSharesOutstanding-Basic 242.6242.6242.6AverageCommonSharesOutstanding-Diluted 243.6244.4244.5Theaccompanyingnotesareanintegralpartoftheseconsolidatedfinancialstatements.

69 AMERENCORPORATIONCONSOLIDATEDSTATEMENTOFCOMPREHENSIVEINCOME(Inmillions)YearEndedDecember31, 2015 2014 2013IncomefromContinuingOperations$585$593$518OtherComprehensiveIncomefromContinuingOperations,NetofTaxesPensionandotherpostretirementbenefitplanactivity,netofincometaxes(benefit)of$3,$(7),and$16,respectively 6(12)30ComprehensiveIncomefromContinuingOperations 591581548Less:ComprehensiveIncomefromContinuingOperationsAttributabletoNoncontrollingInterests 6 66ComprehensiveIncomefromContinuingOperationsAttributabletoAmerenCommonShareholders585575542Income(Loss)fromDiscontinuedOperations,NetofTaxes51(1)(223)OtherComprehensiveLossfromDiscontinuedOperations,NetofIncomeTaxes(Benefit)of$-,$-,and$(10),respectively--(18)ComprehensiveIncome(Loss)fromDiscontinuedOperations 51(1)(241)Less:ComprehensiveIncomefromDiscontinuedOperationsAttributabletoNoncontrollingInterest

--1ComprehensiveIncome(Loss)fromDiscontinuedOperationsAttributabletoAmerenCommonShareholders51(1)(242)ComprehensiveIncomeAttributabletoAmerenCommonShareholders$636$574$300Theaccompanyingnotesareanintegralpartoftheseconsolidatedfinancialstatements.

70 AMERENCORPORATIONCONSOLIDATEDBALANCESHEET(Inmillions,exceptpershareamounts)December31, 2015 2014 ASSETSCurrentAssets:Cashandcashequivalents$292$5Accountsreceivable-trade(lessallowancefordoubtfulaccountsof$19and$21,respectively) 388 423Unbilledrevenue 239 265Miscellaneousaccountsandnotesreceivable 98 81Materialsandsupplies 538 524Currentregulatoryassets 260 295Othercurrentassets 88 86Assetsofdiscontinuedoperations(Note16) 14 15Totalcurrentassets 1,917 1,694PropertyandPlant,Net 18,799 17,424InvestmentsandOtherAssets:Nucleardecommissioningtrustfund 556 549 Goodwill 411 411Regulatoryassets 1,382 1,582Otherassets 575 629Totalinvestmentsandotherassets 2,924 3,171TOTALASSETS$23,640$22,289LIABILITIESANDEQUITYCurrentLiabilities:Currentmaturitiesoflong-termdebt$395$120Short-termdebt 301 714Accountsandwagespayable 777 711Taxesaccrued 43 46Interestaccrued 89 85Currentregulatoryliabilities 80 106Othercurrentliabilities 379 434Liabilitiesofdiscontinuedoperations(Note16) 29 33Totalcurrentliabilities 2,093 2,249Long-termDebt,Net 6,880 6,085DeferredCreditsandOtherLiabilities:Accumulateddeferredincometaxes,net 3,885 3,571Accumulateddeferredinvestmenttaxcredits 60 64Regulatoryliabilities 1,905 1,850Assetretirementobligations 618 396Pensionandotherpostretirementbenefits 580 705Otherdeferredcreditsandliabilities 531 514Totaldeferredcreditsandotherliabilities 7,579 7,100CommitmentsandContingencies(Notes2,10,and15)AmerenCorporationShareholders'Equity:Commonstock,$.01parvalue,400.0sharesauthorized-sharesoutstandingof242.6 2 2Otherpaid-incapital,principallypremiumoncommonstock 5,616 5,617Retainedearnings 1,331 1,103Accumulatedothercomprehensiveloss (3)(9)TotalAmerenCorporationshareholders'equity 6,946 6,713NoncontrollingInterests 142 142Totalequity 7,088 6,855TOTALLIABILITIESANDEQUITY$23,640$22,289Theaccompanyingnotesareanintegralpartoftheseconsolidatedfinancialstatements.

71 AMERENCORPORATIONCONSOLIDATEDSTATEMENTOFCASHFLOWS(Inmillions)YearEndedDecember31, 2015 2014 2013CashFlowsFromOperatingActivities:Netincome$636$592$295Loss(Income)fromdiscontinuedoperations,netoftax (51)1223Adjustmentstoreconcilenetincome(loss)tonetcashprovidedbyoperatingactivities:ProvisionforCallawayconstructionandoperatinglicense 69--Depreciationandamortization 777710666Amortizationofnuclearfuel 978171Amortizationofdebtissuancecostsandpremium/discounts 222224Deferredincometaxesandinvestmenttaxcredits,net 369451410Allowanceforequityfundsusedduringconstruction (30)(34)(37)Stock-basedcompensationcosts 242527 Other (10)(24)23Changesinassetsandliabilities:

Receivables 8331(60)Materialsandsupplies (14)360Accountsandwagespayable (2)1081Taxesaccrued (24)(44)(195)Regulatoryassetsandliabilities 94(281)29Assets,other 533020Liabilities,other (56)(28)(14)Pensionandotherpostretirementbenefits (9)(10)(28)Counterpartycollateral,net (7)2241Netcashprovidedbyoperatingactivities-continuingoperations 2,0211,5571,636Netcashprovided(usedin)byoperatingactivities-discontinuedoperations (4)(6)57Netcashprovidedbyoperatingactivities 2,0171,5511,693CashFlowsFromInvestingActivities:Capitalexpenditures (1,917)(1,785)(1,379)Nuclearfuelexpenditures (52)(74)(45)Purchasesofsecurities-nucleardecommissioningtrustfund (363)(405)(214)Salesandmaturitiesofsecurities-nucleardecommissioningtrustfund 349391196Proceedsfromnotereceivable-MarketingCompany 20956Contributionstonotereceivable-MarketingCompany (8)(89)(5)Other 20111Netcashusedininvestingactivities-continuingoperations (1,951)(1,856)(1,440)Netcashprovidedby(usedin)investingactivities-discontinuedoperations (25)139(283)Netcashusedininvestingactivities (1,976)(1,717)(1,723)CashFlowsFromFinancingActivities:Dividendsoncommonstock (402)(390)(388)Dividendspaidtononcontrollinginterestholders (6)(6)(6)Short-termdebt,net (413)346368Maturities,redemptionsandrepurchasesoflong-termdebt (120)(697)(399)Issuancesoflong-termdebt 1,197898278Capitalissuancecosts (12)(11)(2)Other 2 1-Netcashprovidedby(usedin)financingactivities-continuingoperations 246141(149)Netchangeincashandcashequivalents 287(25)(179)Cashandcashequivalentsatbeginningofyear 530209Cashandcashequivalentsatendofyear$292$5$30CashPaid(Refunded)DuringtheYear:Interest(netof$17,$18,and$37capitalized,respectively)$335$333$393Incometaxes,net (15)(27)8Theaccompanyingnotesareanintegralpartoftheseconsolidatedfinancialstatements.

72 AMERENCORPORATIONCONSOLIDATEDSTATEMENTOFSHAREHOLDERS'EQUITY(Inmillions)December31, 2015 2014 2013CommonStock:Beginningofyear

$2$2$2Sharesissued

---Commonstock,endofyear 2 22OtherPaid-inCapital:Beginningofyear 5,6175,6325,616Stock-basedcompensationactivity (1)(15)16Otherpaid-incapital,endofyear 5,6165,6175,632RetainedEarnings:Beginningofyear 1,1039071,006NetincomeattributabletoAmerencommonshareholders 630586289 Dividends (402)(390)(388)Retainedearnings,endofyear 1,3311,103907AccumulatedOtherComprehensiveIncome(Loss):Derivativefinancialinstruments,beginningofyear

--25Changeinderivativefinancialinstruments

--(21)Divestitureofderivativefinancialinstruments(Note16)

--(4)Derivativefinancialinstruments,endofyear

---Deferredretirementbenefitcosts,beginningofyear (9)3(33)Changeindeferredretirementbenefitcosts 6(12)29Divestitureofdeferredretirementbenefitcosts(Note16)

--7Deferredretirementbenefitcosts,endofyear (3)(9)3Totalaccumulatedothercomprehensiveincome(loss),endofyear (3)(9)3TotalAmerenCorporationShareholders'Equity$6,946$6,713$6,544NoncontrollingInterests:Beginningofyear 142142151Netincomeattributabletononcontrollinginterestholders 6 66Dividendspaidtononcontrollinginterestholders (6)(6)(6)Divestitureofnoncontrollinginterest(Note16)

--(9)Noncontrollinginterests,endofyear 142142142TotalEquity$7,088$6,855$6,686Commonstocksharesatendofyear 242.6242.6242.6Theaccompanyingnotesareanintegralpartoftheseconsolidatedfinancialstatements.

73 UNIONELECTRICCOMPANY(d/b/aAMERENMISSOURI)STATEMENTOFINCOMEANDCOMPREHENSIVEINCOME(Inmillions)YearEndedDecember31, 2015 2014 2013OperatingRevenues:

Electric$3,470$3,388$3,379 Gas 137164161 Other 2 11Totaloperatingrevenues 3,6093,5533,541OperatingExpenses:

Fuel 878826845Purchasedpower 111126133Gaspurchasedforresale 578278Otheroperationsandmaintenance 925939909ProvisionforCallawayconstructionandoperatinglicense(Note2) 69--Depreciationandamortization 492473454Taxesotherthanincometaxes 335322319Totaloperatingexpenses 2,8672,7682,738OperatingIncome 742785803OtherIncomeandExpenses:Miscellaneousincome 526058Miscellaneousexpense 111211Totalotherincome 414847InterestCharges219211210IncomeBeforeIncomeTaxes 564622640IncomeTaxes209229242NetIncome 355393398OtherComprehensiveIncome-

--ComprehensiveIncome$355$393$398NetIncome$355$393$398PreferredStockDividends3 33NetIncomeAvailabletoCommonShareholder$352$390$395TheaccompanyingnotesastheyrelatetoAmerenMissouriareanintegralpartofthesefinancialstatements.

74 UNIONELECTRICCOMPANY(d/b/aAMERENMISSOURI)BALANCESHEET(Inmillions,exceptpershareamounts)December31, 2015 2014 ASSETSCurrentAssets:Cashandcashequivalents$199$1Advancestomoneypool 36-Accountsreceivable-trade(lessallowancefordoubtfulaccountsof$7and$8,respectively) 174 190Accountsreceivable-affiliates 54 65Unbilledrevenue 128 146Miscellaneousaccountsandnotesreceivable 78 35Materialsandsupplies 387 347Currentregulatoryassets 89 163Othercurrentassets 41 43Totalcurrentassets 1,186 990PropertyandPlant,Net 11,183 10,867InvestmentsandOtherAssets:Nucleardecommissioningtrustfund 556 549Regulatoryassets 605 695Otherassets 321 373Totalinvestmentsandotherassets 1,482 1,617TOTALASSETS$13,851$13,474LIABILITIESANDSHAREHOLDERS'EQUITYCurrentLiabilities:Currentmaturitiesoflong-termdebt$266$120Short-termdebt

-97Accountsandwagespayable 417 405Accountspayable-affiliates 56 56Taxesaccrued 31 32Interestaccrued 59 58Currentregulatoryliabilities 28 18Othercurrentliabilities 120 117Totalcurrentliabilities 977 903Long-termDebt,Net 3,844 3,861DeferredCreditsandOtherLiabilities:Accumulateddeferredincometaxes,net 2,844 2,757Accumulateddeferredinvestmenttaxcredits 58 61Regulatoryliabilities 1,172 1,147Assetretirementobligations 612 389Pensionandotherpostretirementbenefits 234 274Otherdeferredcreditsandliabilities 28 30Totaldeferredcreditsandotherliabilities 4,948 4,658CommitmentsandContingencies(Notes2,10,14,and15)Shareholders'Equity:Commonstock,$5parvalue,150.0sharesauthorized-102.1sharesoutstanding 511 511Otherpaid-incapital,principallypremiumoncommonstock 1,822 1,569Preferredstock 80 80Retainedearnings 1,669 1,892Totalshareholders'equity 4,082 4,052TOTALLIABILITIESANDSHAREHOLDERS'EQUITY$13,851$13,474TheaccompanyingnotesastheyrelatetoAmerenMissouriareanintegralpartofthesefinancialstatements.

75 UNIONELECTRICCOMPANY(d/b/aAMERENMISSOURI)STATEMENTOFCASHFLOWS(Inmillions)YearEndedDecember31, 2015 2014 2013CashFlowsFromOperatingActivities:Netincome$355$393$398Adjustmentstoreconcilenetincometonetcashprovidedbyoperatingactivities:ProvisionforCallawayconstructionandoperatinglicense 69--Depreciationandamortization 476442419Amortizationofnuclearfuel 978171FACprudencereviewcharges

--26Amortizationofdebtissuancecostsandpremium/discounts 6 77Deferredincometaxesandinvestmenttaxcredits,net 8224565Allowanceforequityfundsusedduringconstruction (22)(32)(31)Other 2 31Changesinassetsandliabilities:

Receivables 72(10)(59)Materialsandsupplies (39)845Accountsandwagespayable 32542Taxesaccrued 1(197)100Regulatoryassetsandliabilities 117(68)68Assets,other 265218Liabilities,other 4-(29)Pensionandotherpostretirementbenefits (2)12Netcashprovidedbyoperatingactivities 1,2479501,143CashFlowsFromInvestingActivities:Capitalexpenditures (622)(747)(648)Nuclearfuelexpenditures (52)(74)(45)Purchasesofsecurities-nucleardecommissioningtrustfund (363)(405)(214)Salesandmaturitiesofsecurities-nucleardecommissioningtrustfund 349391196Moneypooladvances,net (36)-24 Other-(2)-Netcashusedininvestingactivities (724)(837)(687)CashFlowsFromFinancingActivities:Dividendsoncommonstock (575)(340)(460)Returnofcapitaltoparent

-(215)-Dividendsonpreferredstock (3)(3)(3)Short-termdebt,net (97)97-Moneypoolborrowings,net

-(105)105Redemptions,repurchases,andmaturitiesoflong-termdebt (120)(109)(249)Issuancesoflong-termdebt 249350-Capitalissuancecosts (3)(3)-Capitalcontributionfromparent 2242154Netcashusedinfinancingactivities (325)(113)(603)Netchangeincashandcashequivalents 198-(147)Cashandcashequivalentsatbeginningofyear 11148Cashandcashequivalentsatendofyear$199$1$1Noncashfinancingactivity-capitalcontributionfromparent$38$9$-CashPaid(Refunded)DuringtheYear:Interest(netof$12,$16,and$16capitalized,respectively)$212$203$212Incometaxes,net 7221586TheaccompanyingnotesastheyrelatetoAmerenMissouriareanintegralpartofthesefinancialstatements.

76 UNIONELECTRICCOMPANY(d/b/aAMERENMISSOURI)STATEMENTOFSHAREHOLDERS'EQUITY(Inmillions)December31, 2015 2014 2013CommonStock$511$511$511OtherPaid-inCapital:Beginningofyear 1,5691,5601,556Capitalcontributionfromparent(Note1) 2532244Returnofcapitaltoparent(Note1)

-(215)-Otherpaid-incapital,endofyear 1,8221,5691,560PreferredStock 808080RetainedEarnings:Beginningofyear 1,8921,8421,907Netincome 355393398Commonstockdividends (575)(340)(460)Preferredstockdividends (3)(3)(3)Retainedearnings,endofyear 1,6691,8921,842TotalShareholders'Equity$4,082$4,052$3,993TheaccompanyingnotesastheyrelatetoAmerenMissouriareanintegralpartofthesefinancialstatements.

77 AMERENILLINOISCOMPANY(d/b/aAMERENILLINOIS)STATEMENTOFINCOMEANDCOMPREHENSIVEINCOME(Inmillions)YearEndedDecember31, 2015 2014 2013OperatingRevenues:

Electric$1,683$1,522$1,461 Gas 783976847 Other--3Totaloperatingrevenues 2,4662,4982,311OperatingExpenses:Purchasedpower 420343380Gaspurchasedforresale 358533448Otheroperationsandmaintenance 797771693Depreciationandamortization 295263243Taxesotherthanincometaxes 130138132Totaloperatingexpenses 2,0002,0481,896OperatingIncome 466450415OtherIncomeandExpenses:Miscellaneousincome 211710Miscellaneousexpense 12 89Totalotherincome 9 91InterestCharges131112143IncomeBeforeIncomeTaxes 344347273IncomeTaxes127143110NetIncome 217204163OtherComprehensiveLoss,NetofTaxes:Pensionandotherpostretirementbenefitplanactivity,netofincometaxbenefitof$(2),$(2),and$(2),respectively (3)(3)(3)ComprehensiveIncome$214$201$160NetIncome$217$204$163PreferredStockDividends3 33NetIncomeAvailabletoCommonShareholder$214$201$160TheaccompanyingnotesastheyrelatetoAmerenIllinoisareanintegralpartofthesefinancialstatements.

78 AMERENILLINOISCOMPANY(d/b/aAMERENILLINOIS)BALANCESHEET(Inmillions)December31, 2015 2014 ASSETSCurrentAssets:Cashandcashequivalents$71$1Accountsreceivable-trade(lessallowancefordoubtfulaccountsof$12and$13,respectively) 204 212Accountsreceivable-affiliates 22 22Unbilledrevenue 111 119Miscellaneousaccountsreceivable 19 9Materialsandsupplies 151 177Currentregulatoryassets 167 129Othercurrentassets 15 15Totalcurrentassets 760 684PropertyandPlant,Net 6,848 6,165InvestmentsandOtherAssets:

Goodwill 411 411Regulatoryassets 771 883Otherassets 113 61Totalinvestmentsandotherassets 1,295 1,355TOTALASSETS$8,903$8,204LIABILITIESANDSHAREHOLDERS'EQUITYCurrentLiabilities:Currentmaturitiesoflong-termdebt$129$-Short-termdebt

-32Borrowingsfrommoneypool

-15Accountsandwagespayable 249 207Accountspayable-affiliates 66 50Taxesaccrued 13 17Customerdeposits 69 77Mark-to-marketderivativeliabilities 45 42Currentenvironmentalremediation 28 52Currentregulatoryliabilities 39 84Othercurrentliabilities 114 124Totalcurrentliabilities 752 700Long-termDebt,Net 2,342 2,224DeferredCreditsandOtherLiabilities:Accumulateddeferredincometaxes,net 1,480 1,248Accumulateddeferredinvestmenttaxcredits 2 3Regulatoryliabilities 732 703Pensionandotherpostretirementbenefits 271 277Environmentalremediation 205 199Otherdeferredcreditsandliabilities 222 189Totaldeferredcreditsandotherliabilities 2,912 2,619CommitmentsandContingencies(Notes2,14,and15)Shareholders'Equity:Commonstock,noparvalue,45.0sharesauthorized-25.5sharesoutstanding

--Otherpaid-incapital 2,005 1,980Preferredstock 62 62Retainedearnings 825 611Accumulatedothercomprehensiveincome 5 8Totalshareholders'equity 2,897 2,661TOTALLIABILITIESANDSHAREHOLDERS'EQUITY$8,903$8,204TheaccompanyingnotesastheyrelatetoAmerenIllinoisareanintegralpartofthesefinancialstatements.

79 AMERENILLINOISCOMPANY(d/b/aAMERENILLINOIS)STATEMENTOFCASHFLOWS(Inmillions)YearEndedDecember31, 2015 2014 2013CashFlowsFromOperatingActivities:Netincome$217$204$163Adjustmentstoreconcilenetincometonetcashprovidedbyoperatingactivities:Depreciationandamortization 292259238Amortizationofdebtissuancecostsandpremium/discounts 141315Deferredincometaxesandinvestmenttaxcredits,net 221196104 Other (14)(19)4Changesinassetsandliabilities:

Receivables 16(13)50Materialsandsupplies 25(4)15Accountsandwagespayable 37719Taxesaccrued (2)(7)28Regulatoryassetsandliabilities (26)(215)(35)Assets,other 17155Liabilities,other (27)110Pensionandotherpostretirementbenefits (4)(6)(8)Counterpartycollateral,net (3)1443Netcashprovidedbyoperatingactivities 763445651CashFlowsFromInvestingActivities:Capitalexpenditures (918)(835)(701)

Other 5 76Netcashusedininvestingactivities (913)(828)(695)CashFlowsFromFinancingActivities:Dividendsoncommonstock

--(110)Dividendsonpreferredstock (3)(3)(3)Short-termdebt,net (32)32-Moneypoolborrowings,net (15)(41)32Redemptions,repurchases,andmaturitiesoflong-termdebt

-(163)(150)Issuancesoflong-termdebt 248548278Capitalissuancecosts (3)(6)(2)Capitalcontributionfromparent 2515-Other-1-Netcashprovidedbyfinancingactivities 22038345Netchangeincashandcashequivalents 70-1Cashandcashequivalentsatbeginningofyear 1 1-Cashandcashequivalentsatendofyear$71$1$1CashPaid(Refunded)DuringtheYear:Interest(netof$5,$2,and$4capitalized,respectively)$120$110$112Incometaxes,net (113)(44)(23)TheaccompanyingnotesastheyrelatetoAmerenIllinoisareanintegralpartofthesefinancialstatements.

80 AMERENILLINOISCOMPANY(d/b/aAMERENILLINOIS)STATEMENTOFSHAREHOLDERS'EQUITY(Inmillions)December31, 2015 2014 2013CommonStock$-$-$-OtherPaid-inCapitalBeginningofyear 1,9801,9651,965Capitalcontributionfromparent(Note1) 2515-Otherpaid-incapital,endofyear 2,0051,9801,965PreferredStock 626262RetainedEarnings:Beginningofyear 611410360Netincome 217204163Commonstockdividends

--(110)Preferredstockdividends (3)(3)(3)Retainedearnings,endofyear 825611410AccumulatedOtherComprehensiveIncome:Deferredretirementbenefitcosts,beginningofyear 81114Changeindeferredretirementbenefitcosts (3)(3)(3)Deferredretirementbenefitcosts,endofyear 5811Totalaccumulatedothercomprehensiveincome,endofyear 5811TotalShareholders'Equity$2,897$2,661$2,448TheaccompanyingnotesastheyrelatetoAmerenIllinoisareanintegralpartofthesefinancialstatements.

81 AMERENCORPORATION(Consolidated)UNIONELECTRICCOMPANY(d/b/aAmerenMissouri)

AMERENILLINOISCOMPANY(d/b/aAmerenIllinois)COMBINEDNOTESTOFINANCIALSTATEMENTSDecember31,2015NOTE1-

SUMMARY

OFSIGNIFICANTACCOUNTING POLICIES GeneralAmeren,headquarteredinSt.Louis,Missouri,isapublicutilityholdingcompanyunderPUHCA2005.Ameren'sprimaryassetsareitsequityinterestsinits subsidiaries,includingAmerenMissouriandAmeren Illinois.Ameren'ssubsidiariesareseparate,independent legalentitieswithseparatebusinesses,assets,and liabilities.DividendsonAmeren'scommonstockandthe paymentofexpensesbyAmerendependondistributions madetoitbyitssubsidiaries.Ameren'sprincipal subsidiariesarelistedbelow.

UnionElectricCompany,doingbusinessasAmerenMissouri,operatesarate-regulatedelectricgeneration, transmission,anddistributionbusinessandarate-regulatednaturalgastransmissionanddistribution businessinMissouri.AmerenMissouriwas incorporatedinMissouriin1922andissuccessortoa numberofcompanies,theoldestofwhichwas organizedin1881.Itisthelargestelectricutilityinthe stateofMissouri.Itsupplieselectricandnaturalgas servicetoa24,000-square-mileareaincentraland easternMissouri.Thisareahasanestimated populationof2.8millionandincludestheGreaterSt.

Louisarea.AmerenMissourisupplieselectricserviceto 1.2millioncustomersandnaturalgasserviceto 0.1millioncustomers.

AmerenIllinoisCompany,doingbusinessasAmeren Illinois,operatesrate-regulatedelectricandnaturalgas transmissionanddistributionbusinessesinIllinois.

AmerenIllinoiswascreatedbythemergerofCILCO andIPwithandintoCIPSin2010.CIPSwas incorporatedinIllinoisin1923andwasthesuccessor toanumberofcompanies,theoldestofwhichwas organizedin1902.AmerenIllinoissupplieselectricand naturalgasutilityservicetoportionsofcentraland southernIllinoishavinganestimatedpopulationof 3.1millioninanareaof40,000squaremiles.Ameren Illinoissupplieselectricserviceto1.2million customersandnaturalgasserviceto0.8million

customers.Amerenhasvariousothersubsidiariesthatconductactivitiessuchastheprovisionofsharedservices.Ameren alsohasasubsidiary,ATXI,thatoperatesaFERCrate-regulatedelectrictransmissionbusiness.ATXIisdeveloping MISO-approvedelectrictransmissionprojects,includingthe IllinoisRivers,SpoonRiver,andMarkTwainprojects.

Amerenisalsopursuingprojectstoimproveelectric transmissionsystemreliabilitywithinAmerenMissouri's andAmerenIllinois'serviceterritoriesaswellascompetitiveelectrictransmissioninvestmentopportunities outsideoftheseterritories,includinginvestmentsoutsideof

MISO.InDecember2013,AmerencompletedthedivestitureofNewAERtoIPH.InJanuary2014,MedinaValley completeditssaleoftheElgin,GibsonCity,andGrand Towergas-firedenergycenterstoRocklandCapital.In addition,in2013,AmerenabandonedtheMeredosiaand Hutsonvilleenergycentersuponthecompletionofthe divestitureofNewAERtoIPH.Amerenisdemolishingthe Hutsonvilleenergycenterandexpectstodemolishthe Meredosiaenergycenterbeginningin2016.Asaresultof theseevents,AmerenhassegregatedNewAER'sandthe Elgin,GibsonCity,GrandTower,Meredosia,and Hutsonvilleenergycenters'operatingresults,assets,and liabilitiesandpresentedthemseparatelyasdiscontinued operationsforallperiodspresentedinthisreport.Unless otherwisestated,thesenotestothefinancialstatements excludediscontinuedoperationsforallperiodspresented.

SeeNote16-DivestitureTransactionsandDiscontinued Operationsforadditionalinformationregardingthese

transactions.Ameren'sfinancialstatementsarepreparedonaconsolidatedbasis,andthereforeincludetheaccountsofits majority-ownedsubsidiaries.AmerenMissouriandAmeren Illinoishavenosubsidiariesandthereforetheirfinancial statementsarenotpreparedonaconsolidatedbasis.All intercompanytransactionshavebeeneliminated.Alltabular dollaramountsareinmillions,unlessotherwiseindicated.OuraccountingpoliciesconformtoGAAP.Ourfinancialstatementsreflectalladjustments(whichinclude normal,recurringadjustments)thatarenecessary,inour opinion,forafairpresentationofourresults.The preparationoffinancialstatementsinconformitywithGAAP requiresmanagementtomakecertainestimatesand assumptions.Suchestimatesandassumptionsaffect reportedamountsofassetsandliabilities,thedisclosureof contingentassetsandliabilitiesatthedatesoffinancial statements,andthereportedamountsofrevenuesand expensesduringthereportedperiods.Actualresultscould differfromthoseestimates.

RegulationWeareregulatedbytheMoPSC,theICC,andtheFERC.Wedefercertaincostsasassetspursuanttoactionsofrateregulatorsorbecauseofexpectationsthatwewillbe abletorecoversuchcostsinfuturerateschargedto customers.Wealsodefercertainamountsasliabilities pursuanttoactionsofrateregulatorsorbasedonthe expectationthatsuchamountswillbereturnedto customersinfuturerates.Regulatoryassetsandliabilities areamortizedconsistentwiththeperiodofexpected regulatorytreatment.Inadditiontothecostrecovery mechanismsdiscussedinthePurchasedGas,Power,and FuelRate-adjustmentMechanismssectionbelow,Ameren MissouriandAmerenIllinoishaveapprovalsfromrate 82 regulatorstouseothercostrecoverymechanisms.AmerenMissourihasapensionandpostretirementbenefitcost tracker,anuncertaintaxpositionstracker,arenewable energystandardscosttracker,asolarrebateprogram tracker,andtheMEEIAenergyefficiencyrider.Ameren Illinois'andATXI'selectrictransmissionratesaredetermined pursuanttoformularatemaking.Additionally,AmerenIllinois' electricdistributionbusinessparticipatesintheperformance-basedformularatemakingprocessestablishedpursuantto theIEIMA.AmerenIllinoisalsohasanenvironmentalcost rider,anasbestos-relatedlitigationrider,anenergyefficiency rider,aQIPrider,aVBArider,andabaddebtrider.See Note2-RateandRegulatoryMattersforadditional informationonregulatoryassetsandliabilities.CashandCashEquivalentsCashandcashequivalentsincludecashonhandandtemporaryinvestmentspurchasedwithanoriginalmaturityofthreemonthsorless.AllowanceforDoubtfulAccountsReceivableTheallowancefordoubtfulaccountsrepresentsourestimateofexistingaccountsreceivablethatwillultimatelybeuncollectible.Theallowanceiscalculatedbyapplying estimatedlossfactorstovariousclassesofoutstanding receivables,includingunbilledrevenue.Thelossfactors usedtoestimateuncollectibleaccountsarebasedupon bothhistoricalcollectionsexperienceandmanagement's estimateoffuturecollectionssuccessgiventheexistingand anticipatedfuturecollectionsenvironment.AmerenIllinois hasabaddebtriderthatadjustsratesfornetwrite-offsof customeraccountsreceivableaboveorbelowthosebeing collectedinrates.MaterialsandSuppliesMaterialsandsuppliesarerecordedatthelowerofcostormarket.Costisdeterminedbytheaverage-costmethod.Materialsandsuppliesarecapitalizedasinventory whenpurchasedandthenexpensedorcapitalizedasplant assetswheninstalled,asappropriate.Thefollowingtable presentsabreakdownofmaterialsandsuppliesforeachof theAmerenCompaniesatDecember31,2015and2014:

Ameren Missouri AmerenIllinoisAmeren 2015 Fuel (a)........................$173$-$173Gasstoredunderground

.........108797Othermaterialsandsupplies

......20464268Totalmaterialsandsupplies

......$387$151$538 2014 Fuel (a)........................$134$-$134Gasstoredunderground.........16111127Othermaterialsandsupplies......19766263Totalmaterialsandsupplies......$347$177$524(a)Consistsofcoal,oil,andpropane.PurchasedGas,PowerandFuelRate-adjustment MechanismsAmerenMissouriandAmerenIllinoishavevariousrate-adjustmentmechanismsinplacethatprovideforthe recoveryofpurchasednaturalgasandelectricfueland purchasedpowercostswithoutatraditionalratecase proceeding.SeeNote2-RateandRegulatoryMattersfor theregulatoryassetsandliabilitiesrecordedat December31,2015and2014,relatedtotherate-adjustmentmechanismsdiscussedbelow.InAmerenMissouri'sandAmerenIllinois'naturalgasutilityjurisdictions,changesinnaturalgascostsare reflectedinbillingstotheirnaturalgasutilitycustomers throughPGAclauses.Thedifferencebetweenactualnatural gascostsandcostsbilledtocustomersinagivenperiodis deferredasaregulatoryassetorliability.Thedeferred amountiseitherbilledorrefundedtonaturalgasutility customersinasubsequentperiod.InAmerenIllinois'retailelectricutilityjurisdiction,changesinpurchasedpowerandtransmissionservice costsarereflectedinbillingstoitselectricutilitycustomers throughpass-throughrate-adjustmentclauses.The differencebetweenactualpurchasedpowerand transmissionservicecostsandcostsbilledtocustomersin agivenperiodisdeferredasaregulatoryassetorliability.

Thedeferredamountiseitherbilledorrefundedtoelectric utilitycustomersinasubsequentperiod.AmerenMissourihasaFACthatallowsanadjustmentofelectricratesthreetimesperyearforapass-throughto customersof95%ofchangesinfuelandpurchasedpower costs,includingtransportationchargesandrevenues,netof off-systemsales,greaterorlessthantheamountsetin baserates,subjecttoMoPSCprudencereview.The differencebetweentheactualamountsincurredforthese itemsandtheamountsrecoveredfromAmerenMissouri customers'baseratesisdeferredasaregulatoryassetor liability.Thedeferredamountsareeitherbilledorrefunded toelectricutilitycustomersinasubsequentperiod.Asof May30,2015,transmissionrevenuesandsubstantiallyall transmissionchargesareexcludedfromnetenergycosts asaresultoftheApril2015MoPSCelectricrateorder.PropertyandPlant,NetWecapitalizethecostofadditionstoandbettermentsofunitsofpropertyandplant.Thecostincludeslabor,material,applicabletaxes,andoverhead.Anallowancefor fundsusedduringconstruction,asdiscussedbelow,isalso capitalizedasacostofourrate-regulatedassets.

Maintenanceexpenditures,includingnuclearrefuelingand maintenanceoutages,areexpensedasincurred.Whenunits ofdepreciablepropertyareretired,theoriginalcosts,less salvagevalues,arechargedtoaccumulateddepreciation.If environmentalexpendituresarerelatedtoassetscurrently inuse,asinthecaseoftheinstallationofpollutioncontrol 83 equipment,thecostiscapitalizedanddepreciatedovertheexpectedlifeoftheasset.SeeAssetRetirementObligations belowandNote3-PropertyandPlant,Net,foradditional

information.

DepreciationDepreciationisprovidedovertheestimatedlivesofthevariousclassesofdepreciablepropertybyapplyingcompositeratesonastraight-linebasistothecostbasisof suchproperty.Theprovisionfordepreciationforthe AmerenCompaniesin2015,2014,and2013rangedfrom 3%to4%oftheaveragedepreciablecost.AllowanceforFundsUsedDuringConstructionWecapitalizeallowanceforfundsusedduringconstruction,orthecostofborrowedfundsandthecostofequityfunds(preferredandcommonshareholders'equity) applicabletorate-regulatedconstructionexpenditures,in accordancewiththeutilityindustry'saccountingpractice.

Allowanceforfundsusedduringconstructiondoesnot representacurrentsourceofcashfunds.Thisaccounting practiceoffsetstheeffectonearningsofthecostof financingduringconstruction,andittreatssuchfinancing costsinthesamemannerasconstructionchargesforlabor andmaterials.Underacceptedratemakingpractice,cashrecoveryofallowanceforfundsusedduringconstructionandother constructioncostsoccurswhencompletedprojectsare placedinserviceandreflectedincustomerrates.The followingtablepresentstheannualallowanceforfunds usedduringconstructionratesthatwereappliedto constructionprojectsin2015,2014,and2013:201520142013AmerenMissouri

................

7%7%8%AmerenIllinois

..................

6%2%8%GoodwillGoodwillrepresentstheexcessofthepurchasepriceofanacquisitionoverthefairvalueofthenetassets acquired.AmerenandAmerenIllinois'carryingamountof goodwillwas$411millionatDecember31,2015,and 2014.AllofAmeren'sandAmerenIllinois'goodwillat December31,2015and2014,wasassignedtotheAmeren Illinoisreportingunit.WeevaluategoodwillforimpairmentasofOctober31eachyear,ormorefrequentlyifeventsandcircumstances changethatwouldmorelikelythannotreducethefairvalue oftheAmerenIllinoisreportingunitbelowitscarrying amount.Entitiesassessinggoodwillforimpairmenthave theoptionoffirstperformingaqualitativeassessment beforecalculatingthefairvalueofthereportingunit.Ifan entitydetermines,onthebasisofqualitativefactors,that thefairvalueofthereportingunitismorelikelythannot lessthanthecarryingamount,atwo-stepquantitativetest isrequired.Anentityhastheoptiontobypassthequalitativeassessmentinanyperiodandproceeddirectlyto thefirststepofthequantitativetest,whichcomparesthe fairvalueofthereportingunittoitscarryingamount.Ifthe carryingamountofthereportingunitexceedsitsestimated fairvalue,theentityperformsthesecondstep,which requiresanassignmentofthereportingunit'sfairvalueto theindividualassetsandliabilitiesinordertodeterminethe impliedfairvalueofthereportingunit'sgoodwill.Ifthe impliedfairvalueofgoodwillislessthanitscarrying amount,animpairmentlossisrecorded.AmerenandAmerenIllinoiselectedtobypassthequalitativeassessmentandcompletedthefirststepofthe quantitativetestasofOctober31,2015.Basedonthe results,AmerenandAmerenIllinoisdeterminedthatthe estimatedfairvalueoftheAmerenIllinoisreportingunit significantlyexceededitscarryingvalueasofOctober31, 2015,indicatingnoimpairmentofAmeren'sorAmeren Illinois'goodwill.Ameren'sandAmerenIllinois'valuation approachisbasedonamarketparticipantview.Itusesa weightedcombinationofadiscountedcashflowanalysis andamarketmultiplesanalysis.Significantassumptions usedinestimatingthefairvalueoftheAmerenIllinois reportingunitincludediscountandgrowthrates,utility sectormarketperformanceandtransactions,andprojected operatingresultsandcashflows.ThegoodwillassignedtotheAmerenIllinoisreportingunitontheDecember31,2015balancesheetsofAmeren andAmerenIllinoishadnoaccumulatedgoodwill impairmentlosses.AmerenandAmerenIllinoiswill continuetomonitorinternalandexternalfactorsforsigns ofpossibledeclinesinestimatedfairvalueandpotential goodwillimpairment.ImpairmentofLong-livedAssetsWeevaluatelong-livedassetsclassifiedasheldandusedforimpairmentwheneventsorchangesincircumstancesindicatethatthecarryingvalueofsuch assetsmaynotberecoverable.Whetheranimpairmenthas occurredisdeterminedbycomparingtheestimated undiscountedcashflowsattributabletotheassetstothe carryingvalueoftheassets.Ifthecarryingvalueexceeds theundiscountedcashflows,werecognizeanimpairment chargeequaltotheamountbywhichthecarryingvalue exceedstheestimatedfairvalueoftheassets.Intheperiod inwhichwedetermineanassetmeetsheldforsalecriteria, werecordanimpairmentchargetotheextentthebook valueexceedsitsestimatedfairvaluelesscosttosell.We didnotidentifyanyeventsorchangesincircumstancesthat indicatedthatthecarryingvalueoflong-livedassetsmay notberecoverablein2015and2014.EnvironmentalCostsLiabilitiesforenvironmentalcostsarerecordedonanundiscountedbasiswhenitisprobablethataliabilityhasbeenincurredandtheamountoftheliabilitycanbe reasonablyestimated.Costsareexpensedordeferredasa regulatoryassetwhenitisexpectedthatthecostswillbe recoveredfromcustomersinfuturerates.

84 AssetRetirementObligationsWearerequiredtorecordtheestimatedfairvalueoflegalobligationsassociatedwiththeretirementoftangiblelong-livedassetsintheperiodinwhichtheliabilitiesare incurredandtocapitalizeacorrespondingamountaspart ofthebookvalueoftherelatedlong-livedasset.In subsequentperiods,wearerequiredtomakeadjustments toAROsbasedonchangesintheestimatedfairvaluesof theobligations.Correspondingincreasesinassetbook valuesaredepreciatedovertheremainingusefullifeofthe relatedasset.Uncertaintiesastotheprobability,timing,or amountofcashexpendituresassociatedwithAROsaffect ourestimatesoffairvalue.AmerenandAmerenMissouri haverecordedAROsforretirementcostsassociatedwith AmerenMissouri'sCallawayenergycenter decommissioningcosts,CCRfacilities,andriverstructures.

Also,Ameren,AmerenMissouri,andAmerenIllinoishave recordedAROsforretirementcostsassociatedwith asbestosremovalandthedisposalofcertaintransformers.

AmerenandAmerenMissourihaveanuclear decommissioningtrustfundforthedecommissioningof theCallawayenergycenter.Assetremovalcostsaccruedby ourrate-regulatedoperationsthatdonotconstitutelegal obligationsareclassifiedasregulatoryliabilities.See Note2-RateandRegulatoryMatters.ThefollowingtableprovidesareconciliationofthebeginningandendingcarryingamountofAROsforthe yearsendedDecember31,2015and2014:

Ameren Missouri AmerenIllinoisAmerenBalanceatDecember31,2013....$366$3$369Liabilitiesincurred............2-2Liabilitiessettled.............(2)(a)(2)Accretionin2014 (b)...........21(a)21Changeinestimates (c).........246BalanceatDecember31,2014....$389$7 (d)$396Liabilitiesincurred

............3-3Liabilitiessettled

.............(1)(1)(2)Accretionin2015 (b)...........23(a)23Changeinestimates (e).........203(a)203BalanceatDecember31,2015

....$617 (f)$6 (d)$623 (f)(a)Lessthan$1million.(b)AccretionexpensewasrecordedasanincreasetoregulatoryassetsatAmerenMissouriandAmerenIllinois.(c)TheAROincreaseresultedinacorrespondingincreaserecordedto"PropertyandPlant,Net."AmerenIllinoischangeditsfair valueestimateforasbestosremoval.(d)Includedin"Otherdeferredcreditsandliabilities"onthebalance sheet.(e)TheAROincreaseresultedinacorrespondingincreaserecordedto"PropertyandPlant,Net."AmerenandAmerenMissouri increasedtheirAROsrelatedtothedecommissioningofthe Callawayenergycenterby$99milliontoreflectthe2015cost studyandfundinganalysisfiledwiththeMoPSC,theextension oftheestimatedoperatinglifeuntil2044,andareductioninthe discountrateassumption.SeeNote10-CallawayEnergyCenter foradditionalinformation.Inaddition,asaresultofnewfederal regulations,AmerenandAmerenMissourirecordedanincrease of$100milliontotheirAROsassociatedwithCCRstoragefacilities.SeeNote15-CommitmentsandContingenciesfor additionalinformation.AmerenandAmerenMissourialso increasedtheirAROsby$4millionduetoachangeinthe estimatedretirementdatesoftheMeramecandRushIsland energycentersasaresultoftheMoPSC'sApril2015electricrate

order.(f)Balanceincluded$5millionin"Othercurrentliabilities"onthebalancesheetasofDecember31,2015.SeeNote16-DivestitureTransactionsandDiscontinuedOperationsforadditionalinformationontheAROsrelatedtotheabandonedMeredosiaandHutsonville energycenters,whicharepresentedasdiscontinued operationsandthereforenotincludedinthetableabove.NoncontrollingInterestsAsofDecember31,2015and2014,Ameren'snoncontrollinginterestsincludedthepreferredstockofAmerenMissouriandAmerenIllinois.OperatingRevenueTheAmerenCompaniesrecordoperatingrevenueforelectricornaturalgasservicewhenitisdeliveredtocustomers.Weaccrueanestimateofelectricandnatural gasrevenuesforservicerenderedbutunbilledattheendof eachaccountingperiod.AmerenIllinoisparticipatesintheperformance-basedformularatemakingframeworkpursuanttotheIEIMA.In addition,AmerenIllinois'andATXI'selectrictransmission deliveryserviceoperatingrevenuesareregulatedbythe FERC.TheprovisionsoftheIEIMAandtheFERC'selectric transmissionformularateframeworkprovideforannual reconciliationsoftheelectricdeliveryandelectric transmissionservicerevenuerequirementsnecessaryto reflecttheactualrecoverablecostsincurredinagivenyear withtherevenuerequirementsincustomerratesforthat year,includinganallowedreturnonequity.Ineachofthose electricjurisdictions,ifthecurrentyear'srevenue requirementisgreaterthantherevenuerequirement reflectedinthatyear'scustomerrates,anincreaseto electricoperatingrevenueswithanoffsettoaregulatory assetisrecordedtoreflecttheexpectedrecoveryofthose additionalamountsfromcustomerswithinthenexttwo years.Ineachjurisdiction,ifthecurrentyear'srevenue requirementislessthantherevenuerequirementreflected inthatyear'scustomerrates,areductiontoelectric operatingrevenueswithanoffsettoaregulatoryliabilityis recordedtoreflecttheexpectedrefundtocustomerswithin thenexttwoyears.SeeNote2-RateandRegulatory MattersforinformationregardingAmerenIllinois'revenue requirementreconciliationpursuanttotheIEIMA.AccountingforMISOTransactionsMISO-relatedpurchaseandsaletransactionsarerecordedbyAmeren,AmerenMissouri,andAmerenIllinoisusingsettlementinformationprovidedbyMISO.Ameren Missourirecordsthesepurchaseandsaletransactionsona nethourlyposition.AmerenMissourirecordsnetpurchases inasinglehourin"OperatingExpenses-Purchased 85 power"andnetsalesinasinglehourin"OperatingRevenues-Electric"initsstatementofincome.Ameren Illinoisrecordsnetpurchasesin"OperatingExpenses-Purchasedpower"initsstatementofincometoreflectallof itsMISOtransactionsrelatingtotheprocurementofpower foritscustomers.Onoccasion,AmerenMissouri'sand AmerenIllinois'prior-periodtransactionswillberesettled outsidetheroutinesettlementprocessbecauseofachange inMISO'starifforamaterialinterpretationthereof.Inthese cases,AmerenMissouriandAmerenIllinoisrecognize expensesassociatedwithresettlementsoncethe resettlementisprobableandtheresettlementamountcan beestimatedandrecognizerevenuesoncetheresettlement amountisreceived.NuclearFuelAmerenMissouri'scostofnuclearfueliscapitalizedandthenamortizedtofuelexpenseonaunit-of-productionbasis.Thecostischargedto"OperatingExpenses-Fuel"in thestatementofincome.Stock-basedCompensationStock-basedcompensationcostismeasuredatthegrantdatebasedonthefairvalueoftheaward,netofanassumedforfeiturerate.Amerenrecognizesas compensationexpensetheestimatedfairvalueofstock-basedcompensationonastraight-linebasisoverthe requisiteserviceperiod.SeeNote12-Stock-based Compensationforadditionalinformation.ExciseTaxesAmerenMissouriandAmerenIllinoiscollectfromtheircustomerscertainexcisetaxesthatareleviedonthesaleordistributionofnaturalgasandelectricity.Excisetaxesare leviedonAmerenMissouri'selectricandnaturalgas businessesandonAmerenIllinois'naturalgasbusiness.

Theyarerecordedgrossin"OperatingRevenues-Electric,"

"OperatingRevenues-Gas,"and"OperatingExpenses-Taxesotherthanincometaxes"onthestatementofincome orthestatementofincomeandcomprehensiveincome.

ExcisetaxesforelectricserviceinIllinoisareleviedon customersandarethereforenotincludedinAmerenIllinois' revenuesandexpenses.Thefollowingtablepresentsthe excisetaxesrecordedin"OperatingRevenues-Electric,"

"OperatingRevenues-Gas,"and"OperatingExpenses-Taxesotherthanincometaxes"fortheyearsended December31,2015,2014,and2013:201520142013AmerenMissouri

.............$156$151$152AmerenIllinois

...............

576461 Ameren....................$213$215$213UnamortizedDebtDiscounts,Premiums,andIssuance

CostsLong-termdebtdiscounts,premiums,andissuancecostsareamortizedoverthelivesoftherelatedissuances.

Creditfacilityfeesareamortizedoverthecreditfacilityterm.IncomeTaxesAmerenusesanassetandliabilityapproachforitsfinancialaccountingandreportingofincometaxes,in accordancewithauthoritativeaccountingguidance.

Deferredtaxassetsandliabilitiesarerecognizedfor transactionsthataretreateddifferentlyforfinancial reportingandincometaxreturnpurposes.Thesedeferred taxassetsandliabilitiesarebasedonstatutorytaxrates.Werecognizethatregulatorswillprobablyreducefuturerevenuesfordeferredtaxliabilitiesthatwereinitially recordedatratesinexcessofthecurrentstatutoryrate.

Therefore,reductionsindeferredtaxliabilitiesthatwere recordedbecauseofdecreasesinthestatutoryratehave beencreditedtoaregulatoryliability.Aregulatoryassethas beenestablishedtorecognizetheprobablerecovery throughfuturecustomerratesoftaxbenefitsrelatedtothe equitycomponentofallowanceforfundsusedduring construction,aswellastheeffectsoftaxratechanges.Investmenttaxcreditsusedontaxreturnsforprioryearshavebeendeferredasanoncurrentliability.The creditsarebeingamortizedovertheusefullivesofthe relatedinvestment.Deferredincometaxeswererecorded onthetemporarydifferencerepresentedbythedeferred investmenttaxcreditsandacorrespondingregulatory liability.Thisrecognizestheexpectedreductioninratesfor futurelowerincometaxesassociatedwiththeamortization oftheinvestmenttaxcredits.SeeNote13-IncomeTaxes.AmerenMissouri,AmerenIllinois,andalltheotherAmerensubsidiarycompaniesarepartiestoataxallocation agreementwithAmeren(parent)thatprovidesforthe allocationofconsolidatedtaxliabilities.Thetaxallocation agreementspecifiesthateachpartybeallocatedanamount oftaxsimilartothatwhichwouldbeowedorrefundedhad thepartybeenseparatelysubjecttotax.Anynetbenefit attributabletotheparentisreallocatedtotheotherparties.

Thisreallocationistreatedasacapitalcontributiontothe partyreceivingthebenefit.EarningsperShareBasicearningspershareiscomputedbydividingnetincomeattributabletoAmerencommonshareholdersbytheweighted-averagenumberofcommonshares outstandingduringtheperiod.Earningsperdilutedshareis computedbydividingnetincomeattributabletoAmeren commonshareholdersbytheweighted-averagenumberof dilutedcommonsharesoutstandingduringtheperiod.

Earningsperdilutedsharereflectsthepotentialdilutionthat wouldoccurifcertainstock-basedperformanceshareunits weresettled.Thenumberofperformanceshareunits assumedtobesettledwas1.0million,1.8million,and 1.9millionfortheyearsendedDecember31,2015,2014, and2013,respectively.Therewerenopotentiallydilutive securitiesexcludedfromthedilutedearningspershare calculationsfortheyearsendedDecember31,2015,2014, and2013.86 CapitalContributionsandReturnofCapitalIn2015,AmerenMissouriandAmerenIllinoisreceivedcashcapitalcontributionsof$224millionand$25million,respectively,fromAmeren(parent)asaresultofthetax allocationagreement.Additionally,asofDecember31, 2015,AmerenMissouriaccrueda$38millioncapital contributionrelatedtothesameagreement.In2014,AmerenMissouriandAmerenIllinoisreceivedcashcapitalcontributionsof$215millionand$15million, respectively,fromAmeren(parent)asaresultofthetax allocationagreement.Additionally,asofDecember31, 2014,AmerenMissouriaccrueda$9millioncapital contributionrelatedtothesameagreement.Alsoin2014, AmerenMissourireturnedcapitalof$215milliontoAmeren (parent).SupplementalCashFlowInformationThefollowingtablepresentsadditionalinformationregardingAmeren'sconsolidatedstatementofcashflowsfortheyearsendedDecember31,2015,2014,and2013:201520142013Cashpaid(refunded)duringtheyear:

InterestContinuingoperations (a)........$335$333$362Discontinuedoperations (b).......--31$335$333$393Incometaxes,netContinuingoperations

..........$(17)$(41)$116Discontinuedoperations

........214(108)$(15)$(27)$8(a)Netof$17million,$18million,and$20millioncapitalized, respectively.(b)Netof$-million,$-million,and$17millioncapitalized, respectively.SeeNote3-PropertyandPlant,Net,forinformationonaccruedcapitalexpenditures.AccountingChangesandOtherMattersThefollowingisasummaryofrecentlyadoptedauthoritativeaccountingguidance,aswellasguidanceissuedbutnotyetadopted,thatcouldaffecttheAmeren

Companies.RevenuefromContractswithCustomersInMay2014,theFASBissuedauthoritativeaccountingguidancethatchangesthecriteriaforrecognizingrevenuefromacontractwithacustomer.Theunderlyingprincipleof theguidanceisthatanentitywillrecognizerevenueforthe transferofpromisedgoodsorservicestocustomersatan amountthattheentityexpectstobeentitledtoinexchange forthosegoodsorservices.Theguidancealsorequires additionaldisclosurestoenableusersoffinancial statementstounderstandthenature,amount,timing,anduncertaintyofrevenueandcashflowsarisingfrom contractswithcustomers.Entitiescanapplytheguidance retrospectivelytoeachreportingperiodpresentedor retrospectivelybyrecordingacumulativeeffectadjustment toretainedearningsintheperiodofinitialadoption.The AmerenCompaniesarecurrentlyassessingtheimpactsof thisguidanceontheirresultsofoperations,financial position,anddisclosures,includingtheiraccountingfor contributionsinaidofconstructionandsimilar arrangements,aswellasthetransitionmethodthatthey willusetoadopttheguidance.InAugust2015,theFASB deferredtheeffectivedateofthisrevenueguidancetothe firstquarterof2018,withanoptionforentitiestoearly adoptinthefirstquarterof2017.TheAmerenCompanies donotexpecttoearlyadoptthisguidance.AmendmentstotheConsolidationAnalysisInFebruary2015,theFASBissuedauthoritativeaccountingguidancethatamendstheconsolidationanalysisforvariableinterestentitiesandvotinginterestentities.The newguidanceaffects(1)limitedpartnershipsandsimilar legalentities,(2)evaluatingfeespaidtoadecisionmakeror serviceproviderasavariableinterest,(3)theeffectoffee arrangementsontheprimarybeneficiarydetermination, (4)theeffectofrelatedpartiesontheprimarybeneficiary determination,and(5)certaininvestmentfunds.The guidanceiseffectivefortheAmerenCompaniesinthefirst quarterof2016,andcanbeappliedretrospectivelytoeach reportingperiodpresentedorretrospectivelybyrecordinga cumulativeeffectadjustmenttoretainedearningsinthe periodofinitialadoption.TheAmerenCompaniesare currentlyassessingthisguidanceanddonotexpectany materialimpactstotheirresultsofoperations,financial positionorcashflows.PresentationofDebtIssuanceCostsInApril2015,theFASBissuedauthoritativeaccountingguidancetosimplifythepresentationofdebtissuancecostsinthebalancesheet.Theguidancerequiresdebtissuance coststobepresentedasareductiontotheassociateddebt liability.Previously,debtissuancecostswerepresentedin "Otherassets"ontheAmerenCompanies'balancesheets.

TheAmerenCompaniesearlyadoptedthisstandardin2015 andappliedtheguidanceretrospectively.AtDecember31, 2015,debtissuancecostsof$43million,$19million,and

$18millionwerepresentedin"Long-termdebt,net"on Ameren's,AmerenMissouri's,andAmerenIllinois'balance sheets,respectively.AtDecember31,2014,debtissuance costsof$35million,$18million,and$17millionpreviously presentedin"Otherassets"onAmeren's,Ameren Missouri's,andAmerenIllinois'respectivebalancesheets werereclassifiedtoLong-termdebt,net"forcomparative purposes.SeeNote5-Long-TermDebtandEquity Financingsforadditionalinformation.Theimplementation ofthisauthoritativeaccountingguidancedidnotaffectthe AmerenCompanies'resultsofoperationsorcashflows.

87 BalanceSheetClassificationofDeferredIncomeTaxesInNovember2015,theFASBissuedauthoritativeaccountingguidancetosimplifythepresentationofdeferredincometaxesinthebalancesheet.Theguidancerequiresall deferredtaxassetsandliabilities,alongwithanyrelated valuationallowances,tobeclassifiedasnoncurrentonthe balancesheet.Previously,thecurrentportionofdeferred taxeswaspresentedas"Currentaccumulateddeferred incometaxes,net"andthenoncurrentportionofdeferred taxeswaspresentedas"Accumulateddeferredincome taxes,net"ontheAmerenCompanies'balancesheets.The AmerenCompaniesearlyadoptedthisstandardin2015and appliedtheguidanceretrospectively.AtDecember31, 2014,thecurrentdeferredincometaxesof$352million,

$49million,and$160million,whichwerepreviously presentedas"Currentaccumulateddeferredincometaxes, net"onAmeren's,AmerenMissouri's,andAmerenIllinois' respectivebalancesheets,werereclassifiedandpresented in"Accumulateddeferredincometaxes,net"for comparativepurposes.Theimplementationofthis authoritativeaccountingguidancedidnotaffecttheAmeren Companies'resultsofoperationsorcashflows.

LeasesInFebruary2016,theFASBissuedauthoritativeaccountingguidancethatwillrequireanentitytorecognizeassetsandliabilitiesarisingfromalease.Consistentwith currentGAAP,therecognition,measurement,and presentationofexpensesandcashflowsarisingfroma leasewilldependprimarilyonitsclassificationasafinance oroperatinglease.Theguidancealsorequiresadditional disclosurestoenableusersoffinancialstatementsto understandtheamount,timing,anduncertaintyofcash flowsarisingfromleases.Theguidancewillbeeffectivefor theAmerenCompaniesinthefirstquarterof2019,and includesanoptionforentitiestoearlyadopt.Theguidance requiresaretrospectivecumulativeadjustmenttoretained earningsintheperiodofinitialadoption.TheAmeren Companiesarecurrentlyassessingtheimpactsofthis guidanceontheirresultsofoperations,financialposition, cashflowsanddisclosures.NOTE2-RATEANDREGULATORYMATTERSBelowisasummaryofsignificantregulatoryproceedingsandrelatedlawsuits.Weareunabletopredicttheultimateoutcomeofthesematters,thetimingofthe finaldecisionsofthevariousagenciesandcourts,orthe effectonourresultsofoperations,financialposition,or

liquidity.

Missouri2015ElectricRateOrderInApril2015,theMoPSCissuedanorderapprovinga$122millionincreaseinAmerenMissouri'sannualrevenuesforelectricservice,including$109millionrelated totheincreaseinnetenergycostsabovethoseincludedinbaseratespreviouslyauthorizedbytheMoPSC.The revenueincreasewasbasedona9.53%returnoncommon equity,acapitalstructurecomposedof51.8%common equity,andaratebaseof$7.0billiontoreflectinvestments throughDecember31,2014.Ratechangesconsistentwith theorderbecameeffectiveonMay30,2015.TheorderapprovedAmerenMissouri'srequestforcontinueduseoftheFAC;however,itchangedtheFACto excludealltransmissionrevenuesandsubstantiallyall transmissioncharges.Theorderdidnotapprovethe continueduseoftheregulatorytrackingmechanismsfor stormcostsorforvegetationmanagementandinfrastructure inspectioncosts.ThesechangestoAmerenMissouri's recoverymechanismsareexpectedtocontributeto regulatorylag.Theorderdidapprovethecontinueduseof theregulatorytrackingmechanismsforpensionandother postretirementbenefits,renewableenergystandardcosts, solarrebates,anduncertaintaxpositionsthattheMoPSC authorizedinpriorelectricrateorders.Inaddition,theorderapprovedareductiontoNoranda'selectricrateswithanoffsettingincreasein electricratesforAmerenMissouri'sothercustomers.The rateshiftisdesignedtoberevenueneutralforAmeren Missouri.InJune2015,AmerenMissourifiledanappeal withtheMissouriCourtofAppeals,WesternDistrict, concerningthereductiontoNoranda'selectricrates includedintheMoPSC'sorder.InFebruary2016,Ameren Missouriwithdrewitsappeal.

MEEIATheMEEIAestablishedaregulatoryframeworkthat,amongotherthings,requirestheMoPSCtoensurethatautility'sfinancialincentivesarealignedtohelpcustomersuse energymoreefficiently,toprovidetimelycostrecovery,and toprovideearningsopportunitiesassociatedwithcost-effectiveenergyefficiencyprograms.Missouridoesnothave alawmandatingenergyefficiencyprograms.InAugust2012,theMoPSCapprovedAmerenMissouri'scustomerenergyefficiencyprograms,netshared benefits,andperformanceincentivefor2013through2015.

From2013through2015,AmerenMissouriinvested

$134millionincustomerenergyefficiencyprogramsand realized$174millionofnetsharedbenefits.TheMoPSC alsoestablishedaperformanceincentivethatwouldprovide AmerenMissourianopportunitytoearnadditionalrevenues byachievingcertaincustomerenergyefficiencygoals, including$19millionif100%ofthegoalswereachieved duringthethree-yearperiod,withthepotentialtoearna largerperformanceincentiveifAmerenMissouri'senergy savingsexceededthosegoals.InJune2015,theMoPSCstafffiledacomplaintcasewiththeMoPSCregardingthemethodandinputsusedin calculatingtheperformanceincentivefor2014and2015.In November2015,theMoPSCissuedanorderthatadopted theMoPSCstaff'smethodandinputsusedincalculating theperformanceincentivefor2014and2015.Ameren 88 MissourifiledanappealoftheorderwiththeMissouriCourtofAppeals,WesternDistrict.IftheMissouriCourtof AppealsupholdstheMoPSCorder,theperformance incentiveawardedfromthe2014and2015MEEIA programswillbesignificantlylessthantheperformance incentivecalculatedusingAmerenMissouri'sinterpretation.

AmerenMissourihasnotrecordedrevenuesassociated withtheperformanceincentiveforanyoftheMEEIA programyears.AmerenMissouribelievesthatitwill ultimatelybefoundtohaveexceeded100%ofthecustomer energyefficiencygoals,anditthereforeexpectsto recognizerevenuesofatleast$19millionin2016.InFebruary2016,theMoPSCissuedanorderapprovingAmerenMissouri'sMarch2016toFebruary2019 MEEIAplanwhichincludedaportfolioofcustomerenergy efficiencyprogramsalongwitharidertocollectthe programcosts,thethroughputdisincentive,anda performanceincentivefromcustomers.Thethroughput disincentiverecoverywillreplacethenetsharedbenefits thatwerecollectedunderthe2013through2015MEEIA plan.TheMEEIAriderwillallowAmerenMissouritocollect thethroughputdisincentivewithoutatraditionalrate proceeding,untilsuchtimeaslowervolumesresulting fromtheMEEIAprogramsarereflectedinbaserates.

Customerrateswillbebaseduponbothforecastedprogram costsandthroughputdisincentivewhichwillbeannually reconciledtoactualresults.BeginninginMarch2016, AmerenMissouriintendstoinvest$158millionoverthe three-yearperiodincustomerenergyefficiencyprograms.

Inaddition,similartotheMEEIAplanthatendedin December2015,theMoPSC'sorderapproveda performanceincentivethatwouldprovideAmerenMissouri anopportunitytoearnadditionalrevenuesbyachieving certaincustomerenergyefficiencygoals,including

$27millionif100%ofthegoalsareachievedduringthe three-yearperiod,withthepotentialtoearnmoreifAmeren Missouri'senergysavingsexceedthosegoals.Ameren Missourimustachieveatleast25%ofitsenergyefficiency goalsbeforeitearnsaperformanceincentive.

NorandaAmerenMissourisupplieselectricitytoNoranda'saluminumsmelterlocatedinsoutheastMissouriunderalong-termpowersupplyagreement.InMay2015,Ameren MissourinotifiedNorandaofitsintenttoterminatethe agreementeffectiveJune1,2020.IfAmerenMissouri wantstoceaseprovidingelectricitytoNorandafollowing theterminationdate,AmerenMissouriwouldalsobe requiredtoobtainapprovalfromtheMoPSC.OnJanuary8,2016,Norandaannouncedthatproductionhadbeenidledattwoofitsthreepotlinesatthe smelterfollowinganelectricsupplycircuitfailureonassets notownedbyAmerenMissouri.OnJanuary13,2016, Norandaannouncedthatthesmelter's"remaining operationswillbecurtailedonorbeforeMarch12,2016, unless[Noranda]isabletosecureasubstantiallymore sustainablepowerrateforthesmelterandmateriallyimprove[Noranda's]overallliquidity."AmerenMissourihas beenworkingwithNoranda,legislatorsandother stakeholdersonapotentiallegislativesolutiontosupport Noranda'soperations.InitsApril2015electricrateorder,theMoPSCapprovedaratedesignthatestablished$78millionin annualrevenues,netoffuelandpurchasedpowercosts,as Noranda'sportionofAmerenMissouri'srevenue requirement.TheportionofAmerenMissouri'sannual revenuerequirementreflectedinNoranda'selectricrateis basedonthesmelterusingapproximately4.2million megawatthoursannually,whichisalmost100%ofits operatingcapacity.AmerenMissouri'srates,including thoseforNoranda,areseasonal.Noranda'ssummerbase rate(JunethroughSeptember)is$45.78permegawatthour anditswinterbaserate(OctoberthroughMay)is$31.11 permegawatthour.In2016,actualsalesvolumestoNorandawillbesignificantlybelowthesalesvolumesreflectedinrates.Asa result,AmerenMissouriwillnotfullyrecoveritsrevenue requirementuntilratesareadjustedbytheMoPSCina futureelectricratecasetoaccuratelyreflectNoranda's actualsalesvolumes.InlightoftheNoranda announcementsdescribedabove,AmerenMissouriexpects toemployaprovisioninitsFACtariffthat,undercertain circumstances,allowsAmerenMissouritoretainaportion oftherevenuesfromanyoff-systemsalesitmakesasa resultofreducedtariffsalestoNoranda.Thecurrentmarket priceofelectricityislessthanNoranda'selectricrate,and AmerenMissouriexpectsmarketpricestoremainbelow Noranda'selectricrateduring2016.Accordingly,thisFAC provisionwouldnotenableAmerenMissouritofully recoveritsrevenuerequirementundercurrentmarket

conditions.AlthoughAmerenMissourihasnotdecidedwhentofileitsnextelectricratecase,onJanuary11,2016,Ameren MissourifiledanoticewiththeMoPSC,thatwouldenable AmerenMissouritofilearatecaseafter60days.Ameren Missouriexpectstofilearatecasein2016andexpectsthe resultingnewratestoreflectNoranda'sactualsales volumeswhichwouldprospectivelyeliminatetheimpactof thecurrentrevenueshortfall.Theratecasewouldtakeplace overaperiodofupto11monthsfromthedateoffiling.

AmerenMissourimayseekrecoveryoflostrevenuesina filingwiththeMoPSCforcertaincostsincurredbutnot contemporaneouslyrecoveredasaresultofNoranda's reducedoperations.AmerenMissouriwillcontinueto monitorNoranda'ssalesvolumesandtoevaluateregulatory andlegislativeoptionsthatmightmitigateadversefinancial impacts.ThereductioninNoranda'ssalesvolumeswill adverselyaffectAmeren'sandAmerenMissouri'sresultsof operations,financialcondition,andliquidityuntilcustomer ratesareadjustedinafutureratecase.OnFebruary8,2016,Norandafiledvoluntarypetitionsforacourt-supervisedrestructuringprocessunder Chapter11oftheUnitedStatesBankruptcyCode.Inthe 89 filing,NorandareaffirmedthattheremainingpotlinewillcontinuetooperateatthesmelteruntilMarch2016,at whichtimeoperationofthelinewillbecurtailed.Noranda stateditwouldmaintaintheflexibilitytorestartoperations atthesmeltershouldconditionsallow.Forutilityservice throughFebruary8,2016,Norandahadprepaidanamount toAmerenMissouriinexcessofitsutilityserviceusage.

AmerenMissouriexpectstobepaidinfullforutility servicesprovidedafterFebruary8,2016.ATXITransmissionProjectsInMay2015,theMoPSCgrantedATXIacertificateofconvenienceandnecessityfortheseven-mileportionoftheIllinoisRiversprojectlocatedinMissouri.InJune2015,ATXImadeafilingwiththeMoPSCrequestingacertificateofconvenienceandnecessityforthe MarkTwainproject.TheMarkTwainprojectisaMISO-approved100-miletransmissionlinelocatedinnortheast Missouri.AdecisionisexpectedfromtheMoPSCin2016.

Illinois IEIMAUndertheprovisionsoftheIEIMA'sperformance-basedformularate-makingframework,whichcurrentlyextendsthrough2019,AmerenIllinois'electricdelivery serviceratesaresubjecttoanannualrevenuerequirement reconciliationtoitsactualrecoverablecosts.Throughout eachyear,AmerenIllinoisrecordsaregulatoryassetora regulatoryliabilityandacorrespondingincreaseor decreasetooperatingrevenuesforanydifferencesbetween therevenuerequirementreflectedincustomerratesforthat yearanditsestimateoftheprobableincreaseordecreasein therevenuerequirementexpectedtoultimatelybeapproved bytheICCbasedonthatyear'sactualrecoverablecosts incurred.AsofDecember31,2015,AmerenIllinoishad recordedregulatoryassetsof$62millionand$103million, includinginterest,toreflectitsexpected2015andthe2014 approvedrevenuerequirementreconciliationadjustments, respectively.AsofDecember31,2014,AmerenIllinoishad recordeda$65millionregulatoryassettoreflectits approved2013revenuerequirementreconciliation adjustment,whichwascollected,withinterest,from customersduring2015.InDecember2015,theICCissuedanorderinAmerenIllinois'annualupdatefilingapprovinga$106million increaseinAmerenIllinois'electricdeliveryservicerevenue requirementbeginninginJanuary2016.Thisupdate reflectsanincreasetotheannualformularatebasedon 2014actualrecoverablecostsandexpectednetplant additionsfor2015,anincreasetoincludethe2014revenue requirementreconciliationadjustment,whichwasrecorded asaregulatoryassetatDecember31,2015,andadecrease fortheconclusionofthe2013revenuerequirement reconciliationadjustment,whichwasfullycollectedfrom customersin2015.InDecember2013,theICCissuedanorderthatdisallowed,inpart,therecoveryfromcustomersofthedebt premiumcostspaidbyAmerenIllinoisforatenderofferin August2012torepurchaseoutstandingseniorsecured notes.AsaresultoftheICCorder,in2013,Amerenand AmerenIllinoiseachrecordedapretaxchargetoearnings of$15millionrelatingtothepartialdisallowanceofthedebt premiumcosts.InDecember2014,theICCissuedanorder thatallowedpartialrecoveryfromcustomersofthe previouslydisalloweddebtpremiumcosts.Accordingly,in 2014,AmerenandAmerenIllinoiseachrecordedapretax increasetoearningsof$11milliontoreflectthepartial recoveryofthedebtpremiumcosts.AmerenandAmeren Illinoisrecordedtheeffectsofthe2013and2014ordersto "Interestcharges"withacorrespondingoffsetto "Regulatoryassets."2015NaturalGasDeliveryServiceRateOrderInDecember2015,theICCissuedarateorderthatapprovedanincreaseinrevenuesforAmerenIllinois'naturalgasdeliveryserviceof$45million.Therevenue increasewasbasedona9.6%returnoncommonequity,a capitalstructurecomposedof50%commonequity,anda ratebaseof$1.2billion.Therateorderwasbasedona 2016futuretestyear.Theratechangeswereineffectin January2016.Inaddition,therateorderapprovedtheVBA forresidentialandsmallnonresidentialcustomers beginningin2016.2015ICCPurchasedPowerReconciliationInJanuary2015,theICCissuedanorderthatapprovedAmerenIllinois'reconciliationofrevenuescollectedunderitspurchasedpowerridermechanismand AmerenIllinois'relatedcumulativepowerusagecost.Inthe firstquarterof2015,basedontheJanuary2015order, bothAmerenandAmerenIllinoisrecordeda$15million increasetoelectricrevenuesfortherecoveryofthis cumulativepowerusagecostfromelectriccustomers.ATXITransmissionProjectTheSpoonRiverprojectisaMISO-approved46-miletransmissionlinetobeconstructedinnorthwestIllinois.InSeptember2015,theICCgrantedacertificateofpublic convenienceandnecessityandprojectapprovalforthe SpoonRiverproject.

FederalAmerenIllinoisElectricTransmissionRateRefundInJuly2012,theFERCissuedanorderconcludingthatAmerenIllinoisimproperlyincludedacquisitionpremiums,includinggoodwill,indeterminingthecommonequityused initselectrictransmissionformularateandthereby inappropriatelyrecoveredahigheramountfromitselectric transmissioncustomers.TheorderrequiredAmerenIllinois tomakerefundstocustomersforsuchimproperlyincluded

amounts.90 InJuly2015,theFERCapprovedasettlementagreementbetweenAmerenIllinoisandtheaffectedcustomers.ThesettlementagreementrequiredAmeren Illinoistomakerefundsandpaymentsof$8millionto electrictransmissioncustomers,allofwhichwaspaidin 2015.ThesettlementagreementalsorequiredAmeren Illinoistotakeotheractions,suchasreducingcommon equityforelectrictransmissionratemakingpurposesona prospectivebasis.Thetransmissionratesthatbecame effectiveonJanuary1,2016,reflecttheseadjustments.FERCComplaintCasesInNovember2013,acustomergroupfiledacomplaintcasewiththeFERCseekingareductionintheallowedbasereturnoncommonequityfortheFERC-regulated transmissionratebaseundertheMISOtarifffrom12.38%

to9.15%.InDecember2015,anadministrativelawjudge issuedaninitialdecisionintheNovember2013complaint casethatwouldlowertheallowedbasereturnoncommon equityto10.32%andwouldrequirecustomerrefundstobe issuedforthe15-monthperiodendingFebruary2015.The allowedbasereturnoncommonequityintheinitialdecision wasbasedonmultipleinputs,includingobservablemarket dataforthesixmonthsendedJune30,2015.TheFERCis expectedtoissueafinalorderontheNovember2013 complaintcasebyOctober2016.AsthemaximumFERC-allowedrefundperiodfortheNovember2013complaintcaseendedinFebruary2015, anothercustomercomplaintcasewasfiledinFebruary 2015.TheFebruary2015complaintcaseseeksareduction intheallowedbasereturnoncommonequityfortheFERC-regulatedtransmissionratebaseundertheMISOtariffto 8.67%.Theinitialdecisionfromanadministrativelawjudge intheFebruary2015complaintcase,whichwill subsequentlyrequireFERCapproval,isexpectedtobe issuedbyJune2016.OnJanuary6,2015,aFERC-approvedincentiveadderofupto50basispointsontheallowedbasereturnon commonequityforourparticipationinanRTObecame effective.BeginningwithitsJanuary6,2015effectivedate,theincentiveadderwillreduceanyrefundtocustomers relatingtoareductionoftheallowedbasereturnon commonequityfromthecomplaintcasesdiscussedabove.AsofDecember31,2015,AmerenandAmerenIllinoishadcurrentregulatoryliabilitiesof$45millionand

$32million,respectively,representingtheirestimatesofthe potentialrefundsfromtheNovember12,2013refund effectivedatethroughDecember31,2015.Amerenand AmerenIllinoisrecordedliabilitiestoreflecttheallowed basereturnoncommonequityintheinitialdecisionforthe November2013complaintcaserefundperiod,andthe observablemarketdataforthesixmonthsended December31,2015,fortheFebruary2015complaintcase refundperiod.Ameren'sandAmerenIllinois'liabilitiesalso reflecttheJanuary6,2015incentiveadderdiscussed above.AmerenMissourididnotrecordaliabilityasof December31,2015,anditdoesnotexpectthatareduction intheFERC-allowedbasereturnoncommonequityfor MISOtransmissionownerswouldbematerialtoitsresults ofoperations,financialposition,orliquidity.CombinedConstructionandOperatingLicenseIn2008,AmerenMissourifiledanapplicationwiththeNRCforaCOLforasecondnuclearunitatAmerenMissouri'sexistingCallawayCounty,Missouri,energy centersite.In2009,AmerenMissourisuspendeditsefforts tobuildasecondnuclearunitatitsexistingCallawaysite, andtheNRCsuspendedreviewoftheCOLapplication.Prior tosuspendingitsefforts,AmerenMissourihadcapitalized

$69millionrelatedtotheproject.Primarilybecauseof changesinvendorsupportforlicensingeffortsattheNRC, AmerenMissouri'sassessmentoflong-termcapacity needs,decliningcostsofalternativegeneration technologies,andtheregulatoryframeworkinMissouri, AmerenMissouridiscontinueditseffortstolicenseand buildasecondnuclearunitatitsexistingCallawaysite.Asa resultofthisdecision,inthesecondquarterof2015, AmerenandAmerenMissourirecognizeda$69million noncashpretaxprovisionforallofthepreviouslycapitalized COLcosts.AmerenMissourihaswithdrawnitsCOL applicationwiththeNRC.

91 RegulatoryAssetsandLiabilitiesInaccordancewithauthoritativeaccountingguidanceregardingaccountingfortheeffectsofcertaintypesofregulation,wedefercertaincostsasregulatoryassetspursuanttoactionsofregulatorsorbecauseweexpecttorecoversuchcostsinrateschargedtocustomers.Wemayalsodefercertainamountsasregulatoryliabilitiesbecauseofactionsofregulatorsor becauseweexpectthatsuchamountswillbereturnedtocustomersinfuturerates.Thefollowingtablepresentsourregulatory assetsandregulatoryliabilitiesatDecember31,2015and2014:

2015 2014 Ameren Missouri AmerenIllinoisAmeren Ameren Missouri AmerenIllinoisAmerenCurrentregulatoryassets:Under-recoveredFAC (a)(b)..............................$37$-$37$128$-$128Under-recoveredIllinoiselectricpowercosts (c)..............-33-22Under-recoveredPGA (c)................................-88-2020MTMderivativelosses (d)...............................294574324274Energyefficiencyriders (e)..............................23-233-3IEIMArevenuerequirementreconciliationadjustment (a)(f)......-103103-6565FERCrevenuerequirementreconciliationadjustment (a)(g)......-812--3Totalcurrentregulatoryassets

............................$89$167$260$163$129$295Noncurrentregulatoryassets:Pensionandpostretirementbenefitcosts (h)................$95$202$297$148$275$423Incometaxes (i).......................................25442582533256Assetretirementobligations (j)...........................-44-55Callawaycosts (a)(k)....................................32-3236-36Unamortizedlossonreacquireddebt (a)(l)...................69691387280152Contaminatedfacilitiescosts (m)..........................-230230-251251MTMderivativelosses (d)...............................1517519014144158Stormcosts (a)(n)......................................-99-33Demand-sidecostsbeforetheMEEIAimplementation (a)(o).....31-3144-44Workers'compensationclaims (p)........................67137714Creditfacilitiesfees (q).................................4-45-5Constructionaccountingforpollutioncontrolequipment (a)(r)...20-2021-21Solarrebateprogram (a)(s)...............................74-7488-88IEIMArevenuerequirementreconciliationadjustment (a)(f)......-6262-101101FERCrevenuerequirementreconciliationadjustment (a)(g)......-511-812 Other..............................................5497613Totalnoncurrentregulatoryassets

.........................$605$771$1,382$695$883$1,582Currentregulatoryliabilities:Over-recoveredFAC (b).................................$9$-$9$-$-$-Over-recoveredIllinoiselectricpowercosts (c)...............-66-2626Over-recoveredPGA (c).................................3-322527MTMderivativegains (d)................................1611716117FERCrevenuerequirementreconciliationadjustment (g).......----1111EstimatedrefundforFERCcomplaintcases,orders,andaudit findings (t).........................................-3245-2125Totalcurrentregulatoryliabilities

..........................$28$39$80$18$84$106Noncurrentregulatoryliabilities:Incometaxes (u)......................................$36$6$42$41$14$55Uncertaintaxpositionstracker (v).........................6-67-7Removalcosts (w).....................................9336711,6058866431,529Assetretirementobligation (j)............................167-167182-182Baddebtriders (x).....................................-66-77Pensionandpostretirementbenefitcoststracker (y)...........19-1924-24Energyefficiencyriders (e)..............................-3636-3939Renewableenergycredits (z).............................-12121-1Stormtracker (aa).....................................9-96-6 Other..............................................213---Totalnoncurrentregulatoryliabilities

.......................$1,172$732$1,905$1,147$703$1,850(a)Theseassetsearnareturn.

92 (b)Under-recoveredorover-recoveredfuelcoststoberecoveredorrefundedthroughtheFAC.Specificaccumulationperiodsaggregatetheunder-recoveredorover-recoveredcostsoverfourmonths,anyrelatedadjustmentsthatoccuroverthefollowingfourmonths,andtherecoveryfromorrefundtocustomersthatoccursoverthenexteightmonths.(c)Under-recoveredorover-recoveredcostsfromutilitycustomers.Amountswillberecoveredfrom,orrefundedto,customerswithinoneyearofthedeferral.(d)Deferralofcommodity-relatedderivativeMTMlossesorgains.SeeNote7-DerivativeFinancialInstrumentsforadditionalinformation.

(e)TheAmerenMissouribalancerelatestotheMEEIA.BeginninginJanuary2014,theMEEIAriderallowedAmerenMissouritocollectfromorrefundtocustomersanyannualdifferenceintheactualamountsincurredandtheamountscollectedfromcustomersfortheMEEIAprogram costsanditsnetsharedbenefits.UndertheMEEIArider,collectionsfromorrefundstocustomersoccuroneyearaftertheprogramcostsandlostrevenuesareincurred.TheAmerenIllinoisbalancerelatestoaregulatorytrackingmechanismtorecoveritselectricandnaturalgascostsassociatedwithdeveloping,implementing,andevaluatingcustomerenergyefficiencyanddemandresponseprograms.Anyunder-recoveryorover-recoverywillbecollectedfromorrefundedtocustomersoverthe12monthsfollowingtheplanyear.(f)ThedifferencebetweenAmerenIllinois'annualrevenuerequirementcalculatedundertheIEIMA'sperformance-basedformularatemakingframeworkandtherevenuerequirementincludedincustomerratesforthatyear.SubjecttoICCapproval,theseamountswillbecollectedfrom orrefundedtocustomerswithinterestwithintwoyears.(g)AmerenIllinois'andATXI'sannualrevenuerequirementreconciliationadjustmentscalculatedpursuanttotheFERC'selectrictransmissionformularatemakingframework.Theunder-recoveryorover-recoverywillberecoveredfromorrefundedtocustomerswithintwoyears.(h)Thesecostsarebeingamortizedinproportiontotherecognitionofpriorservicecosts(credits)andactuariallosses(gains)attributabletoAmeren'spensionplanandpostretirementbenefitplans.SeeNote11-RetirementBenefitsforadditionalinformation.(i)Taxbenefitsrelatedtotheequitycomponentofallowanceforfundsusedduringconstruction,aswellastheeffectsoftaxratechanges.Thiswillberecoveredovertheexpectedlifeoftherelatedassets.(j)RecoverableorrefundableremovalcostsforAROs,includingnetrealizedandunrealizedgainsandlossesrelatedtothenucleardecommissioningtrustfundinvestments.SeeNote1-SummaryofSignificantAccountingPolicies-AssetRetirementObligationsand

Investments.(k)AmerenMissouri'sCallawayenergycenteroperationsandmaintenanceexpenses,propertytaxes,andcarryingcostsincurredbetweentheplantin-servicedateandthedatetheplantwasreflectedinrates.Thesecostsarebeingamortizedovertheremaininglifeoftheenergycenter's originaloperatinglicensethrough2024.(l)Lossesrelatedtoreacquireddebt.Theseamountsarebeingamortizedoverthelivesoftherelatednewdebtissuancesortheoriginallivesoftheolddebtissuancesifnonewdebtwasissued.(m)TherecoverableportionofaccruedenvironmentalsiteliabilitiesthatwillbecollectedfromelectricandnaturalgascustomersthroughICC-approvedcostrecoveryriders.Theperiodofrecoverywilldependonthetimingofremediationexpenditures.SeeNote15-Commitmentsand Contingenciesforadditionalinformation.(n)Stormcostsfrom2013and2015deferredinaccordancewiththeIEIMA.Thesecostsarebeingamortizedoverfive-yearperiodsbeginningin2013and2015,respectively.(o)Demand-sidecostsincurredpriortoimplementationoftheMEEIAin2013,includingthecostsofdeveloping,implementing,andevaluatingcustomerenergyefficiencyanddemandresponseprograms.CostsincurredfromMay2008throughSeptember2008arebeingamortizedover a10-yearperiodthatbeganinMarch2009.CostsincurredfromOctober2008throughDecember2009arebeingamortizeduntilMay2017.

CostsincurredfromJanuary2010throughFebruary2011arebeingamortizedoverasix-yearperiodthatbeganinAugust2011.Costsincurred fromMarch2011throughJuly2012arebeingamortizedoverasix-yearperiodthatbeganinJanuary2013.CostsincurredfromAugust2012 throughDecember2012arebeingamortizedoverasix-yearperiodthatbeganinJune2015.(p)Theperiodofrecoverywilldependonthetimingofactualexpenditures.

(q)AmerenMissouri'scostsincurredtoenterintoandmaintaintheMissouriCreditAgreement.AdditionalcostswereincurredinDecember2014toamendandrestatetheMissouriCreditAgreement.Thesecostsarebeingamortizedoverthelifeofthecreditfacility,endinginDecember 2019,toconstructionworkinprogress,whichwillbedepreciatedwhenassetsareplacedintoservice.(r)TheMoPSC'sMay2010electricrateorderallowedAmerenMissouritorecordanallowanceforfundsusedduringconstructionforpollutioncontrolequipmentatitsSiouxenergycenteruntilthecostofthatequipmentwasincludedincustomerratesbeginningin2011.Thesecosts arebeingamortizedovertheexpectedlifeoftheSiouxenergycenter,whichiscurrentlythrough2033.(s)CostsassociatedwithAmerenMissouri'ssolarrebateprogrambeginninginAugust2012tofulfillitsrenewableenergyportfoliorequirement.Thesecostsarebeingamortizedoverthreeyears,beginninginJune2015.(t)EstimatedrefundstotransmissioncustomersrelatedtoFERCorders.SeeAmerenIllinoisElectricTransmissionRateRefundandFERCComplaintCasesabove.(u)Unamortizedportionofinvestmenttaxcreditsandreductionstodeferredtaxliabilitiesrecordedatratesinexcessofcurrentstatutoryrates.Theunamortizedportionofinvestmenttaxcreditsandthereductiontodeferredtaxliabilitiesarebeingamortizedovertheexpectedlifeofthe underlyingassets.(v)Thetrackerisamortizedoverthreeyears,beginningfromthedatetheamountsareincludedinrates.SeeNote13-IncomeTaxesforadditional information.(w)Estimatedfundscollectedfortheeventualdismantlingandremovalofplantfromservice,netofsalvagevalue,uponretirementrelatedtoourrate-regulatedoperations.(x)AregulatorytrackingmechanismforthedifferencebetweenthelevelofbaddebtincurredbyAmerenIllinoisunderGAAPandthelevelofsuchcostsincludedinelectricandnaturalgasrates.Theover-recoveryrelatingto2013wasrefundedtocustomersfromJune2014throughMay 2015.Theover-recoveryrelatingto2014willberefundedtocustomersfromJune2015throughMay2016.Theover-recoveryrelatingto2015 willberefundedtocustomersfromJune2016throughMay2017.(y)AregulatorytrackingmechanismforthedifferencebetweenthelevelofpensionandpostretirementbenefitcostsincurredbyAmerenMissouriunderGAAPandthelevelofsuchcostsincludedinrates.ForperiodspriortoDecember2014,theMoPSC'sApril2015electricrateorder directedtheamortizationtooccuroverthreetofiveyears,beginninginJune2015.ForperiodsafterDecember2014,theamortizationperiod willbedeterminedinafutureelectricratecase.

93 (z)TheAmerenMissouribalanceincludesthecostsofrenewableenergycreditstofulfillAmerenMissouri'srenewableenergyportfoliorequirementfromAugust2012throughDecember2013,whichwerelessthantheamountincludedinrates.ThesecostsarebeingamortizedoverthreeyearsbeginninginJune2015.TheAmerenIllinoisbalanceincludesfundscollectedfromcustomersforthepurchaseofrenewable energycreditsthroughIPAprocurementsfordistributedgeneration.Thebalancewillbeamortizedasrenewableenergycreditsarepurchased.(aa)AregulatorytrackingmechanismatAmerenMissouriforthedifferencebetweenthelevelofstormcostsincurredinaparticularyearandthelevelofsuchcostsincludedinrates.ForperiodspriortoDecember2014,theMoPSC'sApril2015electricrateorderdirectedtheamortization tooccuroverfiveyears,beginninginJune2015.ForperiodsafterDecember2014,theamortizationperiodwillbedeterminedinafuture electricratecase.TheApril2015MoPSCorderdidnotapprovethecontinueduseoftheregulatorytrackingmechanismsforstormcosts.Ameren,AmerenMissouri,andAmerenIllinoiscontinuallyassesstherecoverabilityoftheirregulatoryassets.Undercurrentaccountingstandards,regulatoryassetsarechargedtoearningswhenitisnolongerprobablethatsuchamountswillberecoveredthroughfuturerevenues.Totheextentthatpaymentsofregulatoryliabilitiesarenolongerprobable,theamounts arecreditedtoearnings.NOTE3-PROPERTYANDPLANT,NETThefollowingtablepresentspropertyandplant,net,foreachoftheAmerenCompaniesatDecember31,2015and2014:

Ameren Missouri (a)AmerenIllinoisOtherAmeren (a)2015Propertyandplant,atoriginalcost:

Electric.................................................................$17,521$7,253$387$25,161Naturalgas

..............................................................4451,997-2,44217,9669,25038727,603Less:Accumulateddepreciationandamortization

..................................7,4602,63225510,34710,5066,61813217,256Constructionworkinprogress:Nuclearfuelinprocess

.....................................................275--275 Other..................................................................4022306361,268Propertyandplant,net

.......................................................$11,183$6,848$768$18,799 2014 Propertyandplant,atoriginalcost:

Electric.................................................................$17,052$6,517$344$23,913Naturalgas..............................................................4311,854-2,28517,4838,37134426,198Less:Accumulateddepreciationandamortization

..................................7,0862,4222519,75910,3975,9499316,439Constructionworkinprogress:Nuclearfuelinprocess.....................................................209--209 Other..................................................................261216299776Propertyandplant,net.......................................................$10,867$6,165$392$17,424(a)AmountsinAmerenandAmerenMissouriincludetwoCTsunderseparatecapitalleaseagreements.Thegrosscumulativeassetvalueofthoseagreementswas$233millionatDecember31,2015and2014.ThetotalaccumulateddepreciationassociatedwiththetwoCTswas$72million and$66millionatDecember31,2015and2014,respectively.Inaddition,AmerenMissourihasinvestmentsindebtsecurities,whichwere classifiedasheld-to-maturityandrecordedin"Otherassets",relatedtothetwoCTsfromthecityofBowlingGreenandAudrainCounty.Asof December31,2015and2014,thecarryingvalueofthesedebtsecuritieswas$288millionand$294million,respectively.ThefollowingtableprovidesaccruedcapitalandnuclearfuelexpendituresatDecember31,2015,2014,and2013,whichrepresentnoncashinvestingactivityexcludedfromtheaccompanyingstatementsofcashflows:

Ameren (a)Ameren Missouri Ameren IllinoisAccruedcapitalexpenditures:

2015...................................................................................$235$85$92 2014...................................................................................1817259 2013...................................................................................1757486Accruednuclearfuelexpenditures:

2015...................................................................................1616(b)2014...................................................................................1313(b) 2013...................................................................................88(b)(a)IncludesamountsforAmerenregistrantandnonregistrantsubsidiaries.

(b)Notapplicable.

94 NOTE4-SHORT-TERMDEBTANDLIQUIDITYTheliquidityneedsoftheAmerenCompaniesaretypicallysupportedthroughtheuseofavailablecash,drawingsundercommittedcreditagreements,commercialpaperissuances,orinthecaseofAmerenMissouriandAmerenIllinois,short-termintercompanyborrowings.CreditAgreementsTheCreditAgreementsprovideatotalof$2.1billionofcreditthroughtheirDecember2019maturitydate.Thefacilitiesinclude24international,national,andregionallenders,withnosinglelenderprovidingmorethan$115millionofcreditin aggregate.TheobligationsofeachborrowerundertherespectiveCreditAgreementstowhichitisapartyareseveralandnotjoint.Exceptunderlimitedcircumstancesrelatingtoexpensesandindemnities,theobligationsofAmerenMissouriandAmerenIllinoisundertherespectiveCreditAgreementsarenotguaranteedbyAmerenoranyothersubsidiaryofAmeren.The followingtablepresentsthemaximumaggregateamountavailabletoeachborrowerundereachfacilitywhichwillexpirein December2019(theamountbeingeachborrower's"BorrowingSublimit"):

MissouriCreditAgreement IllinoisCreditAgreement Ameren..........................................................................$700$500AmerenMissouri...................................................................800(a)AmerenIllinois.....................................................................(a)800(a)Notapplicable.Amerenhastheoptiontoseekadditionalcommitmentsfromexistingornewlenderstoincreasethetotalfacility sizeoftheCreditAgreementstoamaximumof$1.2billion fortheMissouriCreditAgreementand$1.3billionforthe IllinoisCreditAgreement.Theprincipalamountofeach revolvingloanowedbyaborrowerunderanyoftheCredit Agreementstowhichitisapartywillbedueandpayableno laterthanthematuritydateofsuchCreditAgreement.The principalamountofeachrevolvingloanowedbyAmeren MissouriorAmerenIllinoisundertheapplicableCredit Agreementwillbedueandpayablenolaterthantheearlier ofthematuritydateor364daysafterthedateofsuchloan.

TheCreditAgreementsarecurrentlyscheduledtomaturein December2019,butthematuritydatemaybeextended onceortwiceforadditionalone-yearperiodsuponmutual consentoftheborrowersandlenders.TheobligationsofallborrowersundertheCreditAgreementsareunsecured.Loansareavailableona revolvingbasisundereachoftheCreditAgreements.Funds borrowedmayberepaidand,subjecttosatisfactionofthe conditionstoborrowing,reborrowedfromtimetotime.At theelectionofeachborrower,theinterestratesonsuch loanswillbethealternatebaserateplusthemargin applicabletotheparticularborrowerand/ortheeurodollar rateplusthemarginapplicabletotheparticularborrower.

Theapplicablemarginswillbedeterminedbythe borrower'slong-termunsecuredcreditratingsor,ifnosuch ratingsareineffect,theborrower'scorporate/issuerratingsthenineffect.Theborrowershavereceivedcommitments fromthelenderstoissuelettersofcreditupto$100million undereachoftheCreditAgreements.Inaddition,the issuanceoflettersofcreditissubjecttothe$2.1billion overallcombinedfacilityborrowinglimitationsoftheCredit

Agreements.TheborrowerswillusetheproceedsfromanyborrowingsundertheCreditAgreementsforgeneral corporatepurposes,includingworkingcapital,commercial paperliquiditysupport,issuanceoflettersofcredit,loan fundingundertheAmerenmoneypoolarrangements,and othershort-termintercompanyloanarrangements,orfor payingfeesandexpensesincurredinconnectionwiththe CreditAgreements.BothoftheCreditAgreementsare availabletoAmerentosupportissuancesunderAmeren's commercialpaperprogram,subjecttoborrowingsublimits.

TheMissouriCreditAgreementandtheIllinoisCredit AgreementareavailabletosupportissuancesunderAmeren (parent)'s,AmerenMissouri'sandAmerenIllinois' commercialpaperprograms,respectively.Asof December31,2015,basedoncommercialpaper outstandingandlettersofcreditissuedundertheCredit Agreements,theaggregateamountofcreditcapacity availabletoAmeren(parent),AmerenMissouri,andAmeren Illinois,collectively,was$1.8billion.Ameren,AmerenMissouri,andAmerenIllinoisdidnotborrowundertheCreditAgreementsfortheyearsended December31,2015and2014.

95 CommercialPaperThefollowingtablesummarizestheborrowingactivityandrelevantinterestratesunderAmeren(parent)'s,AmerenMissouri'sandAmerenIllinois'commercialpaperprograms,fortheyearsendedDecember31,2015and2014:

Ameren (parent)Ameren Missouri Ameren Illinois Ameren Consolidated 2015Averagedailycommercialpaperoutstanding

......................................$721$42$4$767Outstandingborrowingsatperiod-end

...........................................301--301Weighted-averageinterestrate

.................................................0.57%0.50%0.44%0.55%Peakcommercialpaperduringperiod (a)..........................................$874$294$48$1,108Peakinterestrate

...........................................................0.91%0.60%0.60%0.91%

2014 Averagedailycommercialpaperoutstanding......................................$423$110$165$639Outstandingborrowingsatperiod-end...........................................5859732714Weighted-averageinterestrate

.................................................0.36%0.38%0.32%0.36%Peakcommercialpaperduringperiod (a)..........................................$625$495$300$910Peakinterestrate

...........................................................0.75%0.70%0.60%0.75%(a)Thetimingofpeakcommercialpaperissuancesvariesbycompany,andthereforethepeakamountspresentedbycompanymightnotequaltheAmerenConsolidatedpeakcommercialpaperissuancesfortheperiod.IndebtednessProvisionsandOtherCovenantsTheinformationbelowisasummaryoftheAmerenCompanies'compliancewithindebtednessprovisionsandothercovenants.TheCreditAgreementscontainconditionsforborrowingsandissuancesoflettersofcredit.Theseinclude theabsenceofdefaultorunmatureddefault,material accuracyofrepresentationsandwarranties(excludingany representationaftertheclosingdateastotheabsenceof materialadversechangeandmateriallitigation,andthe absenceofanynoticeofviolation,liability,orrequirement underanyenvironmentallawsthatcouldhaveamaterial adverseeffect),andobtainmentofrequiredregulatory authorizations.Inaddition,itisaconditionforanyAmeren Illinoisborrowingthat,atthetimeofandaftergivingeffect tosuchborrowing,AmerenIllinoisnotbeinviolationofany limitationonitsabilitytoincurunsecuredindebtedness containedinitsarticlesofincorporation.TheCreditAgreementsalsocontainnonfinancialcovenants,includingrestrictionsontheabilitytoincurliens, totransactwithaffiliates,todisposeofassets,tomake investmentsinortransferassetstoitsaffiliates,andto mergewithotherentities.TheCreditAgreementsrequire eachofAmeren,AmerenMissouri,andAmerenIllinoisto maintainconsolidatedindebtednessofnotmorethan65%

ofitsconsolidatedtotalcapitalizationpursuanttoadefined calculationsetforthintheagreements.AsofDecember31, 2015,theratiosofconsolidatedindebtednesstototal consolidatedcapitalization,calculatedinaccordancewith theprovisionsoftheCreditAgreements,were51%,49%,

and47%,forAmeren,AmerenMissouri,andAmeren Illinois,respectively.Inaddition,undertheIllinoisCredit Agreementand,byvirtueofthecross-defaultprovisionsof theMissouriCreditAgreement,undertheMissouriCredit Agreement,Amerenisrequiredtomaintainaratioofconsolidatedfundsfromoperationsplusinterestexpenseto consolidatedinterestexpenseof2.0to1.0.However,the interestcoveragerequirementappliesonlyatsuchtimesas Amerendoesnothaveaseniorlong-termunsecuredcredit ratingofatleastBaa3fromMoody'sorBBB-fromS&P.As ofDecember31,2015,Amerenexceededtherating requirements;therefore,theinterestcoveragerequirement wasnotapplicable.Anyfailurebyaborrowertosatisfya financialcovenantconstitutesanimmediatedefaultunder theapplicableCreditAgreement.TheCreditAgreementscontaindefaultprovisionsthatapplyseparatelytoeachborrower;provided,however,that adefaultofAmerenMissouriorAmerenIllinoisunderthe applicableCreditAgreementisalsodeemedtoconstitutea defaultofAmerenundersuchagreement.Defaultsincludea cross-defaultresultingfromadefaultofsuchborrower underanyotheragreementcoveringoutstanding indebtednessofsuchborrowerandcertainsubsidiaries (otherthanprojectfinancesubsidiariesandnonmaterial subsidiaries)inexcessof$75millionintheaggregate (includingundertheotherCreditAgreement).However, underthedefaultprovisionsoftheCreditAgreements,any defaultofAmerenunderanyCreditAgreementthatresults solelyfromadefaultofAmerenMissouriorAmerenIllinois thereunderdoesnotresultinacross-defaultofAmeren undertheotherCreditAgreement.Further,theCredit AgreementdefaultprovisionsprovidethatanAmeren defaultunderanyoftheCreditAgreementsdoesnot constituteadefaultbyAmerenMissouriorAmerenIllinois.NoneoftheAmerenCompanies'creditagreementsorfinancingagreementscontaincreditratingtriggersthat wouldcauseadefaultoraccelerationofrepaymentof outstandingbalances.TheAmerenCompanieswerein compliancewiththeprovisionsandcovenantsoftheir creditagreementsatDecember31,2015

.96 MoneyPoolsAmerenhasmoneypoolagreementswithandamongitssubsidiariestocoordinateandprovideforcertainshort-termcashandworkingcapitalrequirements.AmerenMissouri,AmerenIllinois,andATXImayparticipateintheutilitymoneypoolasbothlendersand borrowers.AmerenandAmerenServicesmayparticipatein theutilitymoneypoolonlyaslenders.Surplusinternal fundsarecontributedtothemoneypoolfromparticipants.

Theprimarysourcesofexternalfundsfortheutilitymoney poolaretheCreditAgreementsandthecommercialpaper programs.Thetotalamountavailabletothepool participantsfromtheutilitymoneypoolatanygiventimeis reducedbytheamountofborrowingsmadebyparticipants, butitisincreasedtotheextentthatthepoolparticipantsadvancesurplusfundstotheutilitymoneypoolorremit fundsfromotherexternalsources.Theavailabilityoffunds isalsodeterminedbyfundingrequirementlimits establishedbyregulatoryauthorizations.Participants receivingaloanunderthemoneypoolagreementmust repaytheprincipalamountofsuchloan,togetherwith accruedinterest.Therateofinterestdependsonthe compositionofinternalandexternalfundsintheutility moneypool.Theaverageinterestrateforborrowingunder themoneypoolfortheyearendedDecember31,2015,was 0.11%(2014-0.19%).SeeNote14-RelatedPartyTransactionsfortheamountofinterestincomeandexpensefromthemoney poolarrangementsrecordedbytheAmerenCompaniesfor theyearsendedDecember31,2015,2014,and2013.NOTE5-LONG-TERMDEBTANDEQUITYFINANCINGSThefollowingtablepresentslong-termdebtoutstanding,includingmaturitiesduewithinoneyear,fortheAmerenCompaniesasofDecember31,2015and2014:20152014Ameren(Parent):2.70%Seniorunsecurednotesdue2020

............................................................$350$-3.65%Seniorunsecurednotesdue2026

............................................................

350-Totallong-termdebt,gross

.....................................................................

700-Less:Unamortizeddebtissuancecosts (a)..........................................................

(6)-Long-termdebt,net

........................................................................$694$-AmerenMissouri:Seniorsecurednotes: (b)4.75%Seniorsecurednotesdue2015

..............................................................

-1145.40%Seniorsecurednotesdue2016

..............................................................

260 2606.40%Seniorsecurednotesdue2017

..............................................................

425 4256.00%Seniorsecurednotesdue2018 (c)............................................................

179 1795.10%Seniorsecurednotesdue2018

..............................................................

199 1996.70%Seniorsecurednotesdue2019 (c)............................................................

329 3295.10%Seniorsecurednotesdue2019

..............................................................

244 2445.00%Seniorsecurednotesdue2020

..............................................................

85 853.50%Seniorsecurednotesdue2024

..............................................................

350 3505.50%Seniorsecurednotesdue2034

..............................................................

184 1845.30%Seniorsecurednotesdue2037

..............................................................

300 3008.45%Seniorsecurednotesdue2039 (c)............................................................

350 3503.90%Seniorsecurednotesdue2042 (c)............................................................

485 4853.65%Seniorsecurednotesdue2045

..............................................................

250-Environmentalimprovementandpollutioncontrolrevenuebonds:1992Seriesdue2022 (d)(e)........................................................................

47 4719935.45%Seriesdue2028 (f)....................................................................(f)(f)1998SeriesAdue2033 (d)(e)......................................................................

60 601998SeriesBdue2033 (d)(e)......................................................................

50 501998SeriesCdue2033 (d)(e)......................................................................

50 50Capitalleaseobligations:CityofBowlingGreencapitallease(PenoCreekCT)due2022

............................................

48 54AudrainCountycapitallease(AudrainCountyCT)due2023

.............................................

240 240Totallong-termdebt,gross

.....................................................................

4,135 4,005Less:Unamortizeddiscountandpremium

.........................................................

(6)(6)Less:Unamortizeddebtissuancecosts (a)..........................................................

(19)(18)Less:Maturitiesduewithinoneyear

..............................................................

(266)(120)Long-termdebt,net

........................................................................$3,844$3,861 97 20152014AmerenIllinois:Seniorsecurednotes:6.20%Seniorsecurednotesdue2016 (g)............................................................$54$546.25%Seniorsecurednotesdue2016 (h)............................................................

75 756.125%Seniorsecurednotesdue2017 (h)(i)..........................................................

250 2506.25%Seniorsecurednotesdue2018 (h)(i)...........................................................

144 1449.75%Seniorsecurednotesdue2018 (h)(i)...........................................................

313 3132.70%Seniorsecurednotesdue2022 (h)(i)...........................................................

400 4003.25%Seniorsecurednotesdue2025 (h)............................................................

300 3006.125%Seniorsecurednotesdue2028 (h)...........................................................

60 606.70%Seniorsecurednotesdue2036 (h)............................................................

61 616.70%Seniorsecurednotesdue2036 (g)............................................................

42 424.80%Seniorsecurednotesdue2043 (h)............................................................

280 2804.30%Seniorsecurednotesdue2044 (h)............................................................

250 2504.15%Seniorsecurednotesdue2046 (h)............................................................

250-Environmentalimprovementandpollutioncontrolrevenuebonds:5.90%Series1993due2023 (j)....................................................................(j)(j)5.70%1994ASeriesdue2024 (k)...................................................................(k)(k)1993SeriesB-1due2028 (e)(l).....................................................................

17 17Totallong-termdebt,gross

.....................................................................

2,496 2,246Less:Unamortizeddiscountandpremium

.........................................................

(7)(5)Less:Unamortizeddebtissuancecosts (a)..........................................................

(18)(17)Less:Maturitiesduewithinoneyear

..............................................................

(129)-Long-termdebt,net

........................................................................$2,342$2,224Amerenconsolidatedlong-termdebt,net

..............................................................$6,880$6,085(a)Reflectstheadoptionofthenewauthoritativeaccountingguidanceforthepresentationofdebtissuancecosts.SeeNote1-SummaryofSignificantAccountingPoliciesforadditionalinformation.(b)ThesenotesarecollaterallysecuredbyfirstmortgagebondsissuedbyAmerenMissouriundertheAmerenMissourimortgageindenture.Thenoteshaveafall-awaylienprovisionandwillremainsecuredonlyaslongasanyfirstmortgagebondsissuedundertheAmerenMissourimortgageindentureremainoutstanding.Redemption,purchase,ormaturityofallfirstmortgagebonds,includingfirstmortgagebonds currentlyoutstandingandanythatmaybeissuedinthefuture,wouldresultinareleaseofthefirstmortgagebondscurrentlysecuringthese notes,atwhichtimethesenoteswouldbecomeunsecuredobligations.ConsideringtheAmerenMissouriseniorsecurednotescurrently outstanding,wedonotexpectthefirstmortgagebondlienprotectionassociatedwiththesenotestofallawayuntil2042.(c)AmerenMissourihasagreedthatsolongasanyofthe3.90%seniorsecurednotesdue2042areoutstanding,AmerenMissouriwillnotpermitareleasedatetooccur,andsolongasanyofthe6.70%seniorsecurednotesdue2019,6.00%seniorsecurednotesdue2018and8.45%

seniorsecurednotesdue2039areoutstanding,AmerenMissouriwillnotoptionallyredeem,purchase,orotherwiseretireinfullthe outstandingfirstmortgagebondsnotsubjecttoreleaseprovisions.(d)ThesebondsarecollaterallysecuredbyfirstmortgagebondsissuedbyAmerenMissouriundertheAmerenMissourimortgageindentureandhaveafall-awaylienprovisionsimilartothatofAmerenMissouri'sseniorsecurednotes.Thebondsarealsobackedbyaninsuranceguarantee

policy.(e)Theinterestrates,andtheperiodsduringwhichsuchratesapply,varydependingonourselectionofdefinedratemodes.Maximuminterestratescouldreach18%dependingontheseriesofbonds.Thebondsarecallableat100%ofparvalue.Theaverageinterestratesfor2015and 2014wereasfollows:

2015 2014AmerenMissouri1992Seriesdue2022

.......0.06%0.10%AmerenMissouri1998SeriesAdue2033

.....0.24%0.26%AmerenMissouri1998SeriesBdue2033

.....0.24%0.27%AmerenMissouri1998SeriesCdue2033

.....0.24%0.26%AmerenIllinois1993SeriesB-1due2028

.....0.49%0.21%(f)ThesebondsarefirstmortgagebondsissuedbyAmerenMissouriundertheAmerenMissourimortgagebondindentureandaresecuredbysubstantiallyallAmerenMissouripropertyandfranchises.Thebondsarecallableat100%ofparvalue.Lessthan$1millionprincipalamount ofthebondsremainoutstanding.(g)ThesenotesarecollaterallysecuredbyfirstmortgagebondsissuedbyAmerenIllinoisundertheCILCOmortgageindenture.Thenoteshaveafall-awaylienprovision,andAmerenIllinoiscouldcausethesenotestobecomeunsecuredatanytimebyredeemingthepollutioncontrol bonds5.90%Series1993due2023(ofwhichlessthan$1millionremainsoutstanding).(h)ThesenotesarecollaterallysecuredbymortgagebondsissuedbyAmerenIllinoisundertheAmerenIllinoismortgageindenture.TheyaresecuredbysubstantiallyallpropertyoftheformerIPandCIPS.Thenoteshaveafall-awaylienprovisionandwillremainsecuredonlyaslong asanyseriesoffirstmortgagebondsissuedundertheAmerenIllinoismortgageindentureremainoutstanding.Redemption,purchase,or maturityofallmortgagebonds,includingfirstmortgagebondscurrentlyoutstandingandanythatmaybeissuedinthefuture,wouldresultina releaseofthemortgagebondscurrentlysecuringthesenotes,atwhichtimethesenoteswouldbecomeunsecuredobligations.Consideringthe AmerenIllinoisseniorsecurednotescurrentlyoutstanding,wedonotexpectthemortgagebondlienprotectionassociatedwiththesenotesto fallawayuntil2024.(i)AmerenIllinoishasagreedthatsolongasanyofthe2.70%seniorsecurednotesdue2022areoutstanding,AmerenIllinoiswillnotpermitareleasedatetooccur,andsolongasanyofthe9.75%seniorsecurednotesdue2018,6.25%seniorsecurednotesdue2018and6.125%

98 seniorsecurednotesdue2017areoutstanding,AmerenIllinoiswillnotoptionallyredeem,purchaseorotherwiseretireinfulltheoutstandingfirstmortgagebondsnotsubjecttoreleaseprovisions;therefore,areleasedatewillnotoccursolongasanyofthesenotesremain

outstanding.(j)ThesebondsarefirstmortgagebondsissuedbyAmerenIllinoisundertheCILCOmortgageindenture.TheyaresecuredbysubstantiallyallpropertyoftheformerCILCO.Thebondsarecallableat100%ofparvalue.Lessthan$1millionprincipalamountofthebondsremain

outstanding.(k)ThesebondsaremortgagebondsissuedbyAmerenIllinoisundertheAmerenIllinoismortgageindenture.TheyaresecuredbysubstantiallyallpropertyoftheformerIPandCIPS.Thebondsarecallableat100%ofparvalue.Thebondsarealsobackedbyaninsuranceguaranteepolicy.

Lessthan$1millionprincipalamountofthebondsremainsoutstanding.(l)Thebondsarecallableat100%ofparvalue.Thefollowingtablepresentstheaggregatematuritiesoflong-termdebt,includingcurrentmaturities,fortheAmerenCompaniesatDecember31,2015:

Ameren (parent)(a)Ameren Missouri (a)Ameren Illinois (a)Ameren Consolidated 2016.....................................................................$-$266$129$395 2017.....................................................................-431250681 2018.....................................................................-383457840 2019.....................................................................-581-581 2020.....................................................................35092-442 Thereafter.................................................................3502,3821,6604,392 Total.....................................................................$700$4,135$2,496$7,331(a)Excludesunamortizeddiscountandpremiumanddebtissuancecostsof$6million,$25million,and$25millionatAmeren(parent),AmerenMissouri,andAmerenIllinois,respectively.AllclassesofAmerenMissouri'sandAmerenIllinois'preferredstockareentitledtocumulativedividends,havevotingrights,andarenotsubjecttomandatoryredemption.ThepreferredstockofAmeren'ssubsidiarieswasincludedin"NoncontrollingInterests"onAmeren'sconsolidatedbalancesheet.ThefollowingtablepresentstheoutstandingpreferredstockofAmerenMissouriandAmerenIllinois,whichisredeemable,attheoptionoftheissuer,atthepricesshownbelowas ofDecember31,2015and2014:RedemptionPrice(pershare)20152014AmerenMissouri:Withoutparvalueandstatedvalueof$100pershare,25millionsharesauthorized$3.50Series130,000shares....................$

110.00$13$13$3.70Series40,000shares

....................

104.75 4 4$4.00Series150,000shares

....................

105.625 15 15$4.30Series40,000shares

....................

105.00 4 4$4.50Series213,595shares

....................

110.00 (a)21 21$4.56Series200,000shares

....................

102.47 20 20$4.75Series20,000shares

....................

102.176 2 2$5.50SeriesA14,000shares

....................

110.00 1 1 Total...........................................................$80$80AmerenIllinois:

Withparvalueof$100pershare,2millionsharesauthorized4.00%Series144,275shares....................$

101.00$14$144.08%Series45,224shares

....................

103.00 5 54.20%Series23,655shares

....................

104.00 2 24.25%Series50,000shares

....................

102.00 5 54.26%Series16,621shares

....................

103.00 2 24.42%Series16,190shares

....................

103.00 2 24.70%Series18,429shares

....................

103.00 2 24.90%Series73,825shares

....................

102.00 7 74.92%Series49,289shares

....................

103.50 5 55.16%Series50,000shares

....................

102.00 5 56.625%Series124,274shares

....................

100.00 12 127.75%Series4,542shares

....................

100.00 1 1 Total...........................................................$62$62TotalAmeren

......................................................$142$142(a)Intheeventofvoluntaryliquidation,$105.50.

99 Amerenhas100millionsharesof$0.01parvaluepreferredstockauthorized,withnosuchsharesoutstanding.AmerenMissourihas7.5millionsharesof

$1parvaluepreferencestockauthorized,withnosuch sharesoutstanding.AmerenIllinoishas2.6millionshares ofnoparvaluepreferredstockauthorized,withnosuch sharesoutstanding.

AmerenInNovember2015,Ameren(parent)issued$350millionof2.70%seniorunsecurednotesdueNovember15,2020,withinterestpayablesemiannuallyonMay15and November15ofeachyear,beginningMay15,2016.Ameren (parent)receivedproceedsof$348million,whichwereused torepayaportionofshort-termdebt.InNovember2015,Ameren(parent)issued$350millionof3.65%seniorunsecurednotesdue February15,2026,withinterestpayablesemiannuallyon February15andAugust15ofeachyear,beginning February15,2016.Ameren(parent)receivedproceedsof

$347million,whichwereusedtorepayaportionofshort-termdebt.InMay2014,Ameren(parent)repaidatmaturity$425millionofits8.875%seniorunsecurednotes,plusaccruedinterest.Thenoteswererepaidwithproceedsfrom commercialpaperissuances.InJune2015,Ameren,AmerenMissouri,andAmerenIllinoisfiledaFormS-3shelfregistrationstatement registeringtheissuanceofanindeterminateamountof certaintypesofsecurities.Theregistrationstatement becameeffectiveimmediatelyuponfilingandwillexpirein June2018.AmerenfiledaFormS-3registrationstatementwiththeSECinMay2014,authorizingtheofferingof8.6million additionalsharesofitscommonstockunderDRPlus,which expiresinMay2017.Sharesofcommonstocksoldunder DRPlusare,atAmeren'soption,newlyissuedshares, treasuryshares,orsharespurchasedintheopenmarketor inprivatelynegotiatedtransactions.InOctober2013,AmerenfiledaFormS-8registrationstatementwiththeSEC,authorizingtheofferingof4million additionalsharesofitscommonstockunderits401(k) plan.Sharesofcommonstocksoldunderthe401(k)plan are,atAmeren'soption,newlyissuedshares,treasury shares,orsharespurchasedintheopenmarketorin privatelynegotiatedtransactions.From2013through2015,AmerensharesforitsDRPlusandits401(k)planswerepurchasedintheopen

market.AmerenMissouriInFebruary2016,$260millionprincipalamountofAmerenMissouri's5.40%seniorsecurednotesmaturedandwererepaidwithcashonhandandcommercialpaperborrowings.InApril2015,AmerenMissouriissued$250millionof3.65%seniorsecurednotesdueApril15,2045,withinterestpayablesemiannuallyonApril15andOctober15ofeachyear,beginningOctober15,2015.AmerenMissourireceivedproceedsof

$247million,whichwereusedtorepayoutstandingshort-termdebt,includingshort-termdebtthatAmerenMissouriincurredin connectionwiththerepaymentof$114millionofits4.75%seniorsecurednotesthatmaturedonApril1,2015.InApril2014,AmerenMissouriissued$350millionof3.50%seniorsecurednotesdueApril15,2024,withinterestpayablesemiannuallyonApril15andOctober15ofeachyear,beginningOctober15,2014.AmerenMissourireceived proceedsof$348million,whichwereusedtorepayatmaturity$104millionofits5.50%seniorsecurednotesdueMay15, 2014andtorepayaportionofitsshort-termdebt.ForinformationonAmerenMissouri'scapitalcontributionsandreturnofcapital,refertoCapitalContributionsandReturnofCapitalinNote1-SummaryofSignificantAccountingPolicies.AmerenIllinoisInDecember2015,AmerenIllinoisissued$250millionof4.15%seniorsecurednotesdueMarch15,2046,withinterestpayablesemiannuallyonMarch15andSeptember15,beginningMarch15,2016.AmerenIllinoisreceivedproceedsof$245million,whichwereusedtorepayaportionofitsshort-termdebt.InJanuary2014,AmerenIllinoisredeemedthefollowingenvironmentalimprovementandpollutioncontrolrevenuebondsatparvalueplusaccruedinterest:SeniorSecuredNotesPrincipalAmount5.90%Series1993due2023 (a)...........................................................................$325.70%1994ASeriesdue2024 (a)..........................................................................361993SeriesC-15.95%due2026

.........................................................................351993SeriesC-25.70%due2026

.........................................................................

85.40%1998ASeriesdue2028

...........................................................................195.40%1998BSeriesdue2028

...........................................................................33Totalamountredeemed.................................................................................$163(a)Lessthan$1millionprincipalamountofthebondsremainsoutstandingafterredemption.

100 InJune2014,AmerenIllinoisissued$250millionof4.30%seniorsecurednotesdueJuly1,2044,withinterestpayablesemiannuallyonJanuary1andJuly1,beginningJanuary1,2015.AmerenIllinoisreceivedproceedsof$246million,whichwereusedtorepayaportionofitsshort-termdebt.InDecember2014,AmerenIllinoisissued$300millionof3.25%seniorsecurednotesdueMarch1,2025,withinterestpayablesemiannuallyonMarch1andSeptember1,beginningMarch1,2015.AmerenIllinoisreceivedproceedsof

$298million,whichwereusedtorepayaportionofitsshort-termdebt.ForinformationonAmerenIllinois'capitalcontributions,refertoCapitalContributionsandReturnofCapitalinNote1-SummaryofSignificantAccountingPolicies.IndentureProvisionsandOtherCovenantsAmerenMissouri'sandAmerenIllinois'indentures,creditfacilities,andarticlesofincorporationincludecovenantsandprovisionsrelatedtoissuancesoffirstmortgagebondsandpreferredstock.AmerenMissouriandAmerenIllinoisarerequiredtomeetcertainratiostoissueadditionalfirstmortgagebondsandpreferredstock.Afailuretoachievetheseratioswouldnot resultinadefaultunderthesecovenantsandprovisionsbutwouldrestrictthecompanies'abilitytoissuebondsorpreferred stock.Thefollowingtablesummarizestherequiredandactualinterestcoverageratiosforinterestcharges,dividendcoverage ratios,andbondsandpreferredstockissuableasofDecember31,2015,atanassumedinterestrateof5%anddividendrate of6%.RequiredInterestCoverageRatio (a)ActualInterestCoverageRatioBondsIssuable (b)RequiredDividendCoverageRatio (c)ActualDividendCoverageRatioPreferredStock IssuableAmerenMissouri

.......2.03.8$3,3852.5104.0$2,315AmerenIllinois

.........2.06.33,566 (d)1.52.6203 (e)(a)Coveragerequiredontheannualinterestchargesonfirstmortgagebondsoutstandingandtobeissued.Coverageisnotrequiredincertaincaseswhenadditionalfirstmortgagebondsareissuedonthebasisofretiredbonds.(b)Amountofbondsissuablebasedeitheronrequiredcoverageratiosorunfundedpropertyadditions,whicheverismorerestrictive.Theamountsshownalsoincludebondsissuablebasedonretiredbondcapacityof$946millionand$204millionatAmerenMissouriandAmerenIllinois, respectively.(c)Coveragerequiredontheannualdividendonpreferredstockoutstandingandtobeissued,asrequiredintherespectivecompany'sarticlesof incorporation.(d)AmountofbondsissuablebyAmerenIllinoisbasedonunfundedpropertyadditionsandretiredbondssolelyundertheformerIPmortgageindenture.TheamountofbondsissuablebyAmerenIllinoisisalsosubjecttothelienrestrictionscontainedintheIllinoisCreditAgreement.(e)PreferredstockissuableisrestrictedbytheamountofpreferredstockthatiscurrentlyauthorizedbyAmerenIllinois'articlesofincorporation.Ameren'sindenturedoesnotrequireAmerentocomplywithanyquantitativefinancialcovenants.Theindenturedoes,however,includecertaincross-default provisions.Specifically,either(1)thefailurebyAmerento paywhendueanduponexpirationofanyapplicablegrace periodanyportionofanyAmerenindebtednessinexcessof

$25million,or(2)theaccelerationupondefaultofthe maturityofanyAmerenindebtednessinexcessof

$25millionunderanyindebtednessagreement,including borrowingsundertheCreditAgreementsortheAmeren commercialpaperprogram,constitutesadefaultunderthe indenture,unlesssuchpastdueoraccelerateddebtis dischargedortheaccelerationisrescindedorannulled withinaspecifiedperiod.AmerenMissouriandAmerenIllinoisandcertainothernonregistrantAmerensubsidiariesaresubjectto Section305(a)oftheFederalPowerAct,whichmakesit unlawfulforanyofficerordirectorofapublicutility,as definedintheFederalPowerAct,toparticipateinthe makingorpayingofanydividendfromanyfunds"properly includedincapitalaccount."TheFERChasconsistently interpretedtheprovisiontoallowdividendstobepaidas longas(1)thesourceofthedividendsisclearlydisclosed,(2)thedividendsarenotexcessive,and(3)thereisnoself-dealingonthepartofcorporateofficials.Ataminimum, Amerenbelievesthatdividendscanbepaidbyits subsidiariesthatarepublicutilitiesfromnetincomeand retainedearnings.Inaddition,underIllinoislaw,Ameren Illinoismaynotpayanydividendonitsstockunless, amongotherthings,itsearningsandearnedsurplusare sufficienttodeclareandpayadividendafterprovisionis madeforreasonableandproperreserves,orunlessAmeren IllinoishasspecificauthorizationfromtheICC.AmerenIllinois'articlesofincorporationrequiredividendpaymentsonitscommonstocktobebasedon ratiosofcommonstocktototalcapitalizationandother provisionsrelatedtocertainoperatingexpensesand accumulationsofearnedsurplus.AmerenIllinoishasmade acommitmenttotheFERCtomaintainaminimum30%

ratioofcommonstockequitytototalcapitalization.Asof December31,2015,AmerenIllinois'ratioofcommonstock equitytototalcapitalizationwas51%.InorderfortheAmerenCompaniestoissuesecuritiesinthefuture,theywillhavetocomplywithallapplicable requirementsineffectatthetimeofanysuchissuances.

101 Off-Balance-SheetArrangementsAtDecember31,2015,noneoftheAmerenCompanieshadoff-balance-sheetfinancingarrangements,otherthanoperatingleasesenteredintointheordinarycourseofbusiness,lettersofcredit,andAmerenparentguaranteearrangementsonbehalfofitssubsidiaries.NoneoftheAmerenCompaniesexpecttoengageinanysignificantoff-balance-sheetfinancingarrangementsinthenearfuture.NOTE6-OTHERINCOMEANDEXPENSESThefollowingtablepresentsthecomponentsof"OtherIncomeandExpenses"intheAmerenCompanies'statementsofincome(loss)fortheyearsendedDecember31,2015,2014,and2013:201520142013 Ameren: (a)Miscellaneousincome:Allowanceforequityfundsusedduringconstruction

.........................................$30$34$37Interestincomeonindustrialdevelopmentrevenuebonds

.....................................

272727Interestincome (b)....................................................................

14103 Other..............................................................................

3 8 (c)2Totalmiscellaneousincome

..............................................................$74$79$69Miscellaneousexpense:

Donations..........................................................................$15$10$12 Other..............................................................................

151214Totalmiscellaneousexpense

.............................................................$30$22$26AmerenMissouri:Miscellaneousincome:Allowanceforequityfundsusedduringconstruction

.........................................$22$32$31Interestincomeonindustrialdevelopmentrevenuebonds

.....................................

272727Interestincome

......................................................................

1 1-Other..............................................................................

2--Totalmiscellaneousincome

..............................................................$52$60$58Miscellaneousexpense:

Donations..........................................................................

$5$6$4 Other..............................................................................

6 67Totalmiscellaneousexpense

.............................................................$11$12$11AmerenIllinois:

Miscellaneousincome:Allowanceforequityfundsusedduringconstruction

.........................................

$8$2$6Interestincome (b)....................................................................

12 72 Other..............................................................................

1 8 (c)2Totalmiscellaneousincome

..............................................................$21$17$10Miscellaneousexpense:

Donations..........................................................................

$5$4$4 Other..............................................................................

7 45Totalmiscellaneousexpense

.............................................................$12$8$9(a)IncludesamountsforAmerenregistrantandnonregistrantsubsidiariesandintercompanyeliminations.

(b)IncludesAmerenIllinois'interestincomeontheIEIMArevenuerequirementreconciliationadjustmentregulatoryassets.

(c)IncludesAmerenIllinois'incomeearnedin2014fromcustomer-requestedconstruction.

102 NOTE7-DERIVATIVEFINANCIALINSTRUMENTSWeusederivativestomanagetheriskofchangesinmarketpricesfornaturalgas,power,anduranium,aswellastheriskofchangesinrailtransportationsurcharges throughfueloilhedges.Suchpricefluctuationsmaycause thefollowing:

anunrealizedappreciationordepreciationofourcontractedcommitmentstopurchaseorsellwhen purchaseorsalepricesunderthecommitmentsare comparedwithcurrentcommodityprices; marketvaluesofnaturalgasanduraniuminventories thatdifferfromthecostofthosecommoditiesin inventory;and actualcashoutlaysforthepurchaseofthese commoditiesthatdifferfromanticipatedcashoutlays.Thederivativesthatweusetohedgetheserisksaregovernedbyourriskmanagementpoliciesforforward contracts,futures,options,andswaps.Ournetpositions arecontinuallyassessedwithinourstructuredhedging programstodeterminewhetherneworoffsetting transactionsarerequired.Thegoalofthehedgingprogram isgenerallytomitigatefinancialriskswhileensuringthat sufficientvolumesareavailabletomeetourrequirements.

Contractsweenterintoaspartofourriskmanagement programmaybesettledfinancially,settledbyphysical delivery,ornetsettledwiththecounterparty.ThefollowingtablepresentsopengrosscommoditycontractvolumesbycommoditytypeforderivativeassetsandliabilitiesasofDecember31,2015and2014.AsofDecember31,2015,thesecontractsranthroughOctober2018,March 2021,May2032,andJanuary2019forfueloils,naturalgas,power,anduranium,respectively.Quantity(inmillions,exceptasindicated)20152014 Commodity Ameren Missouri AmerenIllinoisAmeren Ameren Missouri AmerenIllinoisAmerenFueloils(ingallons)(a).........................................35(b)3550(b)50Naturalgas(inmmbtu)

........................................3015118128108136Power(inmegawatthours)

......................................1101111112Uranium(poundsinthousands)

.................................494(b)494332(b)332(a)Fueloilsconsistofheatingoilandultra-low-sulfurdiesel.(b)Notapplicable.Authoritativeaccountingguidanceregardingderivativeinstrumentsrequiresthatallcontractsconsideredtobederivativeinstrumentsberecordedonthebalancesheetat theirfairvalues,unlesstheNPNSexceptionapplies.See Note8-FairValueMeasurementsfordiscussionofour methodsofassessingthefairvalueofderivative instruments.Manyofourphysicalcontracts,suchasour purchasedpowercontracts,qualifyfortheNPNSexception toderivativeaccountingrules.Therevenueorexpenseon NPNScontractsisrecognizedatthecontractpriceupon physicaldelivery.IfwedeterminethatacontractmeetsthedefinitionofaderivativeandisnoteligiblefortheNPNSexception,we reviewthecontracttodeterminewhetheritqualifiesfor hedgeaccounting.Wealsoconsiderwhethergainsor lossesresultingfromsuchderivativesqualifyforregulatory deferral.Derivativecontractsthatqualifyforregulatory deferralarerecordedatfairvalue,withchangesinfairvalue recordedasregulatoryassetsorregulatoryliabilitiesintheperiodinwhichthechangeoccurs.Webelievederivative lossesandgainsdeferredasregulatoryassetsand regulatoryliabilitiesareprobableofrecoveryorrefund throughfuturerateschargedtocustomers.Regulatory assetsandregulatoryliabilitiesareamortizedtooperating incomeasrelatedlossesandgainsarereflectedinrates chargedtocustomers.Therefore,gainsandlossesonthese derivativeshavenoeffectonoperatingincome.Asof December31,2015and2014,allcontractsthatqualifyfor hedgeaccountingreceiveregulatorydeferral.Authoritativeaccountingguidancepermitscompaniestooffsetfairvalueamountsrecognizedfortherightto reclaimcashcollateral(areceivable)ortheobligationto returncashcollateral(aliability)againstfairvalueamounts recognizedforderivativeinstrumentsthatareexecutedwith thesamecounterpartyunderamasternettingarrangement orsimilaragreement.TheAmerenCompaniesdidnotelect toadoptthisguidanceforanyeligiblederivative

instruments.

103 Thefollowingtablepresentsthecarryingvalueandbalancesheetlocationofallderivativecommoditycontracts,noneofwhichweredesignatedashedginginstruments,asofDecember31,2015and2014:BalanceSheetLocation Ameren Missouri AmerenIllinoisAmeren 2015Naturalgas

............Othercurrentassets

..............................$-$1$1Otherassets

....................................1-1 Power................Othercurrentassets

..............................16-16Totalassets (a)..................................$17$1$18Fueloils..............Othercurrentliabilities

............................$22$-$22Otherdeferredcreditsandliabilities

..................7-7Naturalgas............MTMderivativeliabilities

..........................(b)32(b)Othercurrentliabilities

............................6-38Otherdeferredcreditsandliabilities

..................81826 Power................MTMderivativeliabilities

..........................(b)13 (b)Othercurrentliabilities

............................--1 3Otherdeferredcreditsandliabilities

..................

-157 157 Uranium..............Othercurrentliabilities

............................1-1Totalliabilities (c)................................$44$220$264 2014Fueloils..............Othercurrentassets..............................$2$-$2Naturalgas

............Othercurrentassets..............................112 Power................Othercurrentassets..............................15-15Totalassets (a)..................................$18$1$19Fueloils..............Othercurrentliabilities............................$22$-$22Otherdeferredcreditsandliabilities..................7-7Naturalgas............MTMderivativeliabilities

..........................(b)31(b)Othercurrentliabilities............................6-37Otherdeferredcreditsandliabilities..................61319 Power................MTMderivativeliabilities

..........................(b)11(b)Othercurrentliabilities

............................

3-14Otherdeferredcreditsandliabilities

..................

-131131 Uranium..............Othercurrentliabilities 2-2Totalliabilities (c)................................$46$186$232(a)Becauseallcontractsqualifyingforhedgeaccountingreceiveregulatorydeferral,thecumulativeamountofpretaxnetgainsonallderivativeinstrumentsisdeferredasaregulatoryliability.(b)Balancesheetlineitemnotapplicabletoregistrant.(c)Becauseallcontractsqualifyingforhedgeaccountingreceiveregulatorydeferral,thecumulativeamountofpretaxnetlossesonallderivativeinstrumentsisdeferredasaregulatoryasset.Derivativeinstrumentsaresubjecttovariouscredit-relatedlossesintheeventofnonperformancebycounterpartiestothetransaction.Exchange-tradedcontractsaresupportedbythefinancialandcreditqualityoftheclearingmembersoftherespectiveexchangesandhavenominalcreditrisk.Inallothertransactions,weareexposedtocreditrisk.Ourcreditrisk managementprograminvolvesestablishingcreditlimitsandcollateralrequirementsforcounterparties,usingmasternetting arrangementsorsimilaragreements,andreportingdailyexposuretoseniormanagement.Webelievethatenteringintomasternettingarrangementsorsimilaragreementsmitigatestheleveloffinanciallossthatcouldresultfromdefaultbyallowingnetsettlementofderivativeassetsandliabilities.Wegenerallyenterintothefollowing masternettingarrangements:(1)theInternationalSwapsandDerivativesAssociationAgreement,astandardizedfinancialnaturalgasandelectriccontract;(2)theMasterPowerPurchaseandSaleAgreement,createdbytheEdisonElectricInstitute andtheNationalEnergyMarketersAssociation,astandardizedcontractforthepurchaseandsaleofwholesalepower;and (3)theNorthAmericanEnergyStandardsBoardInc.Agreement,astandardizedcontractforthepurchaseandsaleofnatural gas.Thesemasternettingarrangementsallowthecounterpartiestonetsettlesaleandpurchasetransactions.Further, collateralrequirementsarecalculatedatthemasternettingarrangementorsimilaragreementlevelbycounterparty.

104 ThefollowingtableprovidestherecognizedgrossderivativebalancesandthenetamountsofthosederivativessubjecttoanenforceablemasternettingarrangementorsimilaragreementasofDecember31,2015and2014:GrossAmountsNotOffsetontheBalanceSheetCommodityContractsEligibletobeOffsetGrossAmountsRecognizedontheBalanceSheet Derivative InstrumentsCashCollateral Received/Posted (a)Net Amount 2015 Assets:

AmerenMissouri

..............................................$17$1$-$16AmerenIllinois

................................................1--1 Ameren.....................................................$18$1$-$17 Liabilities:

AmerenMissouri

..............................................$44$1$8$35AmerenIllinois

................................................220-3217 Ameren.....................................................$264$1$11$252 2014 Assets:

AmerenMissouri..............................................$18$5$-$13AmerenIllinois................................................1--1 Ameren.....................................................$19$5$-$14 Liabilities:

AmerenMissouri..............................................$46$5$5$36AmerenIllinois................................................186--186 Ameren.....................................................$232$5$5$222(a)Cashcollateralreceivedreducesgrossassetbalancesandisincludedin"Othercurrentliabilities"and"Otherdeferredcreditsandliabilities"onthebalancesheet.Cashcollateralpostedreducesgrossliabilitybalancesandisincludedin"Othercurrentassets"and"Otherassets"onthebalancesheet.ConcentrationsofCreditRiskIndeterminingourconcentrationsofcreditriskrelatedtoderivativeinstruments,wereviewourindividualcounterpartiesandcategorizeeachcounterpartyintogroupingsaccordingtotheprimarybusinessinwhicheachengages.Wecalculatemaximumexposuresbasedonthegrossfairvalueoffinancialinstruments,includingNPNSandotheraccrualcontracts.These exposuresarepresentedonagrossbasis,whichincludeaffiliateexposurenoteliminatedattheconsolidatedAmerenlevel.

Thepotentiallossoncounterpartyexposuresmaybereducedoreliminatedbytheapplicationofmasternettingarrangements orsimilaragreementsandcollateralheld.AsofDecember31,2015,ifcounterpartygroupsweretofailcompletelytoperformoncontracts,Ameren's,AmerenMissouri's,andAmerenIllinois'maximumexposurewouldhavebeenimmaterialwithor withoutconsiderationoftheapplicationofmasternettingarrangementsorsimilaragreementsandcollateralheld.DerivativeInstrumentswithCreditRisk-RelatedContingentFeaturesOurcommoditycontractscontaincollateralprovisionstiedtotheAmerenCompanies'creditratings.Ifweweretoexperienceanadversechangeinourcreditratings,orifacounterpartywithreasonablegroundsforuncertaintyregardingperformanceofanobligationrequestedadequateassuranceofperformance,additionalcollateralpostingsmightberequired.Thefollowingtablepresents,asofDecember31,2015,theaggregatefairvalueofallderivativeinstrumentswithcreditrisk-relatedcontingentfeaturesinagrossliabilityposition,thecashcollateralposted,andtheaggregateamountofadditional collateralthatcounterpartiescouldrequire.Theadditionalcollateralrequiredisthenetliabilitypositionallowedunderthe masternettingarrangementsorsimilaragreementsassuming(1)thecreditrisk-relatedcontingentfeaturesunderlyingthese arrangementsweretriggeredonDecember31,2015,and(2)thosecounterpartieswithrightstodosorequestedcollateral.AggregateFairValueofDerivativeLiabilities (a)CashCollateralPostedPotentialAggregateAmountofAdditionalCollateralRequired (b)2015AmerenMissouri

.....................................$87$9$72AmerenIllinois

.......................................78371 Ameren.............................................$165$12$143(a)BeforeconsiderationofmasternettingarrangementsorsimilaragreementsandincludingNPNSandotheraccrualcontractexposures.(b)Ascollateralrequirementswithcertaincounterpartiesarebasedonmasternettingarrangementsorsimilaragreements,theaggregateamountofadditionalcollateralrequiredtobepostedisdeterminedafterconsiderationoftheeffectsofsucharrangements.

105 NOTE8-FAIRVALUEMEASUREMENTSFairvalueisdefinedastheexchangepricethatwouldbereceivedforanassetorpaidtotransferaliability(anexitprice)intheprincipalormostadvantageousmarketforthe assetorliabilityinanorderlytransactionbetweenmarket participantsonthemeasurementdate.Weusevarious methodstodeterminefairvalue,includingmarket,income, andcostapproaches.Withtheseapproaches,weadopt certainassumptionsthatmarketparticipantswouldusein pricingtheassetorliability,includingassumptionsabout marketriskortherisksinherentintheinputstothe valuation.Inputstovaluationcanbereadilyobservable, market-corroborated,orunobservable.Weusevaluation techniquesthatmaximizetheuseofobservableinputsand minimizetheuseofunobservableinputs.Authoritative accountingguidanceestablishedafairvaluehierarchythat prioritizestheinputsusedtomeasurefairvalue.Allfinancial assetsandliabilitiescarriedatfairvalueareclassifiedand disclosedinoneofthefollowingthreehierarchylevels:Level1:Inputsbasedonquotedpricesinactivemarketsforidenticalassetsorliabilities.Level1assetsand liabilitiesareprimarilyexchange-tradedderivativesand assets,includingcashandcashequivalentsandlisted equitysecurities,suchasthoseheldinAmerenMissouri's nucleardecommissioningtrustfund.ThemarketapproachisusedtomeasurethefairvalueofequitysecuritiesheldinAmerenMissouri'snuclear decommissioningtrustfund.Equitysecuritiesinthisfund arerepresentativeoftheS&P500index,excluding securitiesofAmerenCorporation,ownersand/oroperators ofnuclearpowerplants,andthetrusteeandinvestment managers.TheS&P500indexcomprisesstocksoflarge-capitalizationcompanies.Level2:Market-basedinputscorroboratedbythird-partybrokersorexchangesbasedontransactedmarket data.Level2assetsandliabilitiesincludecertainassets heldinAmerenMissouri'snucleardecommissioningtrust fund,includingcorporatebondsandotherfixed-income securities,UnitedStatesTreasuryandagencysecurities, andcertainover-the-counterderivativeinstruments, includingnaturalgasandfinancialpowertransactions.Fixedincomesecuritiesarevaluedbyusingpricesfromindependentindustryrecognizeddatavendorswho providevaluesthatareeitherexchange-basedormatrix-based.Thefairvaluemeasurementsoffixedincome securitiesclassifiedasLevel2arebasedoninputsotherthanquotedpricesthatareobservablefortheassetor liability.Examplesarematrixpricing,marketcorroborated pricing,andinputssuchasyieldcurvesandindices.Level2 fixedincomesecuritiesinthenucleardecommissioning trustfundareprimarilycorporatebonds,asset-backed securities,andUnitedStatesagencybonds.DerivativeinstrumentsclassifiedasLevel2arevaluedbycorroboratedobservableinputs,suchaspricingservices orpricesfromsimilarinstrumentsthattradeinliquid markets.Ourdevelopmentandcorroborationprocess entailsobtainingmultiplequotesorpricesfromoutside sources.Toderiveourforwardviewtopriceourderivative instrumentsatfairvalue,weaveragethemidpointsofthe bid/askspreads.Tovalidateforwardpricesobtainedfrom outsideparties,wecomparethepricingtorecentlysettled markettransactions.Additionally,areviewofallsourcesis performedtoidentifyanyanomaliesorpotentialerrors.

Further,weconsiderthevolumeoftransactionsoncertain tradingplatformsinourreasonablenessassessmentofthe averagedmidpoint.Thevalueofnaturalgasderivative contractsisbaseduponexchangeclosingpriceswithout significantunobservableadjustments.Thevalueofpower derivativescontractsisbasedupontheuseofmultiple forwardpricesprovidedbythirdparties.Thepricesare averagedandshapedtoamonthlyprofilewhenneeded withoutsignificantunobservableadjustments.Level3:Unobservableinputsthatarenotcorroboratedbymarketdata.Level3assetsandliabilitiesarevaluedby internallydevelopedmodelsandassumptionsor methodologiesthatusesignificantunobservableinputs.

Level3assetsandliabilitiesincludederivativeinstruments thattradeinlessliquidmarkets,wherepricingislargely unobservable.WevalueLevel3instrumentsbyusing pricingmodelswithinputsthatareoftenunobservablein themarket,aswellascertaininternalassumptions.Our developmentandcorroborationprocessentailsobtaining multiplequotesorpricesfromoutsidesources.Asapartof ourreasonablenessreview,anevaluationofallsourcesis performedtoidentifyanyanomaliesorpotentialerrors.Weperformananalysiseachquartertodeterminetheappropriatehierarchyleveloftheassetsandliabilities subjecttofairvaluemeasurements.Financialassetsand liabilitiesareclassifiedintheirentiretyaccordingtothe lowestlevelofinputthatissignificanttothefairvalue measurement.Allassetsandliabilitieswhosefairvalue measurementisbasedonsignificantunobservableinputs areclassifiedasLevel3.

106 ThefollowingtabledescribesthevaluationtechniquesandunobservableinputsutilizedbytheAmerenCompaniesforthefairvalueoffinancialassetsandliabilitiesclassifiedasLevel3inthefairvaluehierarchyfortheperiodsendedDecember31,2015and2014:FairValue Weighted AverageAssetsLiabilitiesValuationTechnique(s)UnobservableInputRangeLevel3Derivativeassetandliability-commoditycontracts (a): 2015NaturalGas$1$(1)OptionmodelVolatilities(%)(b)35-55 45Nodalbasis($/mmbtu)(c)(0.30)-0(0.20)DiscountedcashflowNodalbasis($/mmbtu)(b)(0.10)-0(0.10)Counterpartycreditrisk(%)(c)(d)0.40-12 7AmerenMissouricreditrisk(%)(c)(d)0.40 (e)Power (f)16(170)DiscountedcashflowAverageforwardpeakandoff-peakpricing-forwards/swaps($/MWh)(g)22-39 29EstimatedauctionpriceforFTRs

($/MW)(b)(270)-2,057211Nodalbasis($/MWh)(g)(10)-(1)(3)Counterpartycreditrisk(%)(c)(d)0.86 (e)AmerenIllinoiscreditrisk(%)(c)(d)0.40 (e)Fundamentalenergyproduction

modelEstimatedfuturegasprices

($/mmbtu)(b)3-4 4Escalationrate(%)(b)(h)3 (e)ContractpriceallocationEstimatedrenewableenergycredit costs($/credit)(b)5-7 6Uranium-(1)Optionmodel Volatilities(%)(b)20 (e)DiscountedcashflowAverageforwarduraniumpricing

($/pound)(b)35-42 37AmerenMissouricreditrisk(%)(c)(d)0.40 (e)2014Fueloils$2$(8)Optionmodel Volatilities(%)(c)3-39 32DiscountedcashflowAmerenMissouricreditrisk(%)(c)(d)0.43 (e)Escalationrate(%)(b)(i)5 (e)NaturalGas1(2)Optionmodel Volatilities(%)(c)31-144 63Nodalbasis($/mmbtu)(b)(0.40)-0(0.20)DiscountedcashflowNodalbasis($/mmbtu)(b)(0.40)-0.10(0.20)Counterpartycreditrisk(%)(c)(d)0.43-13 3AmerenMissouriandAmerenIllinois creditrisk(%)(c)(d)0.43 (e)Power (f)11(144)DiscountedcashflowAverageforwardpeakandoff-peak pricing-forwards/swaps($/MWh)(g)27-50 32EstimatedauctionpriceforFTRs

($/MW)(b)(1,833)-2,743171Nodalbasis($/MWh)(b)(6)-0 (2)Counterpartycreditrisk(%)(c)(d)0.26 (e)AmerenMissouriandAmerenIllinois creditrisk(%)(c)(d)0.43 (e)Fundamentalenergyproduction

modelEstimatedfuturegasprices

($/mmbtu)(b)4-5 4Escalationrate(%)(b)(h)0-1 1ContractpriceallocationEstimatedrenewableenergycredit costs($/credit)(b)5-7 6Uranium-(2)DiscountedcashflowAverageforwarduraniumpricing

($/pound)(b)35-40 36(a)Thederivativeassetandliabilitybalancesarepresentednetofcounterpartycreditconsiderations.(b)Generally,significantincreases(decreases)inthisinputinisolationwouldresultinasignificantlyhigher(lower)fairvaluemeasurement.

(c)Generally,significantincreases(decreases)inthisinputinisolationwouldresultinasignificantlylower(higher)fairvaluemeasurement.

(d)Counterpartycreditriskisappliedonlytocounterpartieswithderivativeassetbalances.AmerenMissouriandAmerenIllinoiscreditriskisappliedonlytocounterpartieswithderivativeliabilitybalances.(e)Notapplicable.

(f)Powervaluationsusevisiblethird-partypricingevaluatedbymonthforpeakandoff-peakdemandthrough2019.Valuationsbeyond2019usefundamentallymodeledpricingbymonthforpeakandoff-peakdemand.(g)ThebalanceatAmereniscomprisedofAmerenMissouriandAmerenIllinoispowercontracts,whichresponddifferentlytounobservableinputchangesbecauseoftheiropposingpositions.(h)Escalationrateappliestopowerprices2026andbeyond.

(i)Escalationrateappliestofueloilprices2017andbeyond.

107 Inaccordancewithapplicableauthoritativeaccountingguidance,weconsidernonperformanceriskinourvaluationofderivativeinstrumentsbyanalyzingthecreditstandingof ourcounterpartiesandconsideringanycounterpartycredit enhancements(e.g.,collateral).Theguidancealsorequires thatthefairvaluemeasurementofliabilitiesreflectthe nonperformanceriskofthereportingentity,asapplicable.

Therefore,wehavefactoredtheimpactofourcredit standing,aswellasanypotentialcreditenhancements,into thefairvaluemeasurementofbothderivativeassetsandderivativeliabilities.Includedinourvaluation,andbasedon currentmarketconditions,isavaluationadjustmentfor counterpartydefaultderivedfrommarketdatasuchasthe priceofcreditdefaultswaps,bondyields,andcreditratings.

Nogainsorlossesrelatedtovaluationadjustmentsfor counterpartydefaultriskwererecordedatAmeren,Ameren Missouri,orAmerenIllinoisin2015,2014or2013.At December31,2015and2014,thecounterpartydefaultrisk valuationadjustmentrelatedtoderivativecontractswas immaterialforAmeren,AmerenMissouri,andAmerenIllinois.Thefollowingtablesetsforth,bylevelwithinthefairvaluehierarchy,ourassetsandliabilitiesmeasuredatfairvalueonarecurringbasisasofDecember31,2015:QuotedPricesinActiveMarketsforIdenticalAssetsorLiabilities(Level1)SignificantOther Observable Inputs(Level2)Significant Other Unobservable Inputs(Level3)Total Assets:AmerenDerivativeassets-commoditycontracts (a):Naturalgas................................$-$1$1$2 Power....................................--1616Totalderivativeassets-commoditycontracts.........$-$1$17$18Nucleardecommissioningtrustfund:Cashandcashequivalents....................$4$-$-$4Equitysecurities:U.S.largecapitalization..................364

--364Debtsecurities:U.S.Treasuryandagencysecurities

.........-109-109Corporatebonds

........................ 58 Other................................. 22Totalnucleardecommissioningtrustfund............$368$189$-$557 (b)TotalAmeren..................................$368$190$17$575 Ameren MissouriDerivativeassets-commoditycontracts (a):Naturalgas................................$-$-$1$1 Power....................................--1616Totalderivativeassets-commoditycontracts.........$-$-$17$17Nucleardecommissioningtrustfund:Cashandcashequivalents....................$4$-$-$4Equitysecurities:U.S.largecapitalization..................364

--364Debtsecurities:U.S.Treasuryandagencysecurities

.........-109-109Corporatebonds

........................ 58 Other................................. 22Totalnucleardecommissioningtrustfund............$368$189$-$557 (b)TotalAmerenMissouri...........................$368$189$17$574 Ameren IllinoisDerivativeassets-commoditycontracts (a):Naturalgas................................$-$1$-$1 Liabilities:

AmerenDerivativeliabilities-commoditycontracts (a):Fueloils..................................$29$-$-$29Naturalgas................................162164 Power....................................--170170 Uranium..................................--11TotalAmeren..................................$30$62$172$264 Ameren MissouriDerivativeliabilities-commoditycontracts (a):Fueloils..................................$29$-$-$29Naturalgas................................-13114 Power....................................----

Uranium..................................--11TotalAmerenMissouri...........................$29$13$2$44 Ameren IllinoisDerivativeliabilities-commoditycontracts (a):Naturalgas................................$1$49$-$50 Power....................................--170170TotalAmerenIllinois.............................$1$49$170$220(a)Thederivativeassetandliabilitybalancesarepresentednetofcounterpartycreditconsiderations.(b)Balanceexcludes$(1)millionofreceivables,payables,andaccruedincome,net.

108 Thefollowingtablesetsforth,bylevelwithinthefairvaluehierarchy,ourassetsandliabilitiesmeasuredatfairvalueonarecurringbasisasofDecember31,2014:QuotedPricesinActiveMarketsforIdenticalAssetsorLiabilities(Level1)SignificantOtherObservableInputs(Level2)Significant Other Unobservable Inputs(Level3)Total Assets:AmerenDerivativeassets-commoditycontracts (a):Fueloils.................................$-$-$2$2Naturalgas

...............................

-1 1 2 Power...................................

-41115Totalderivativeassets-commoditycontracts........$-$5$14$19Nucleardecommissioningtrustfund:Cashandcashequivalents...................$1$-$-$1Equitysecurities:U.S.largecapitalization.................364

--364Debtsecurities:U.S.Treasuryandagencysecurities

........-102-102Corporatebonds

....................... 63 Other................................ 17Totalnucleardecommissioningtrustfund...........$365$182$-$547 (b)TotalAmeren.................................$365$187$14$566 Ameren MissouriDerivativeassets-commoditycontracts (a):Fueloils.................................$-$-$2$2Naturalgas

............................... 1 Power...................................

-41115Totalderivativeassets-commoditycontracts........$-$5$13$18Nucleardecommissioningtrustfund:Cashandcashequivalents...................$1$-$-$1Equitysecurities:U.S.largecapitalization.................364

--364Debtsecurities:U.S.Treasuryandagencysecurities

........-102-102Corporatebonds

....................... 63 Other................................ 17Totalnucleardecommissioningtrustfund...........$365$182$-$547 (b)TotalAmerenMissouri..........................$365$187$13$565 Ameren IllinoisDerivativeassets-commoditycontracts (a):Naturalgas...............................$-$-$1$1 Liabilities:

AmerenDerivativeliabilities-commoditycontracts (a):Fueloils.................................$21$-$8$29Naturalgas

...............................

153 256 Power...................................

-1144145 Uranium.................................

--2 2TotalAmeren.................................$22$54$156$232 Ameren MissouriDerivativeliabilities-commoditycontracts (a):Fueloils.................................$21$-$8$29Naturalgas

...............................

110 112 Power...................................

-1 2 3 Uranium.................................

--2 2TotalAmerenMissouri..........................$22$11$13$46 Ameren IllinoisDerivativeliabilities-commoditycontracts (a):Naturalgas...............................$-$43$1$44 Power...................................

--142142TotalAmerenIllinois............................$-$43$143$186(a)Thederivativeassetandliabilitybalancesarepresentednetofcounterpartycreditconsiderations.(b)Balanceexcludes$2millionofreceivables,payables,andaccruedincome,net.

109 ThefollowingtablesummarizesthechangesinthefairvalueoffinancialassetsandliabilitiesclassifiedasLevel3inthefairvaluehierarchyfortheyearendedDecember31,2015:NetDerivativeCommodityContracts Ameren Missouri AmerenIllinoisAmerenFueloils:BeginningbalanceatJanuary1,2015......................................................$(6)$(a)$(6)Realizedandunrealizedgains(losses)includedinregulatoryassets/liabilities:.....................(1)(a)(1)

Settlements........................................................................5(a)5TransfersoutofLevel3...............................................................2(a)2EndingbalanceatDecember31,2015......................................................$-$(a)$-Changeinunrealizedgains(losses)relatedtoassets/liabilitiesheldatDecember31,2015.............$-$(a)$-Naturalgas:

BeginningbalanceatJanuary1,2015......................................................$(1)$-$(1)Realizedandunrealizedgains(losses)includedinregulatoryassets/liabilities:.....................-11 Settlements........................................................................1(1)-EndingbalanceatDecember31,2015......................................................$-$-$-Changeinunrealizedgains(losses)relatedtoassets/liabilitiesheldatDecember31,2015.............$-$-$-

Power:

BeginningbalanceatJanuary1,2015......................................................$9$(142)$(133)Realizedandunrealizedgains(losses)includedinregulatoryassets/liabilities:.....................2(41)(39)Purchases.........................................................................29-29 Settlements

........................................................................(23)13(10)TransfersoutofLevel3...............................................................(1)-(1)EndingbalanceatDecember31,2015......................................................$16$(170)$(154)Changeinunrealizedgains(losses)relatedtoassets/liabilitiesheldatDecember31,2015.............$-$(39)$(39)Uranium:

BeginningbalanceatJanuary1,2015......................................................$(2)$(a)$(2)Realizedandunrealizedgains(losses)includedinregulatoryassets/liabilities:.....................(1)(a)(1)

Settlements........................................................................2(a)2EndingbalanceatDecember31,2015......................................................$(1)$(a)$(1)Changeinunrealizedgains(losses)relatedtoassets/liabilitiesheldatDecember31,2015.............$-$(a)$-(a)Notapplicable.ThefollowingtablesummarizesthechangesinthefairvalueoffinancialassetsandliabilitiesclassifiedasLevel3inthefairvaluehierarchyfortheyearendedDecember31,2014:NetDerivativeCommodityContracts Ameren Missouri AmerenIllinoisAmerenFueloils:

BeginningbalanceatJanuary1,2014.......................................................$5$(a)$5Realizedandunrealizedgains(losses)includedinregulatoryassets/liabilities:.....................(9)(a)(9)

Settlements.........................................................................(2)(a)(2)EndingbalanceatDecember31,2014......................................................$(6)$(a)$(6)Changeinunrealizedgains(losses)relatedtoassets/liabilitiesheldatDecember31,2014..............$(6)$(a)$(6)Naturalgas:

BeginningbalanceatJanuary1,2014.......................................................$-$-$-Realizedandunrealizedgains(losses)includedinregulatoryassets/liabilities:.....................-11 Purchases..........................................................................-(2)(2)

Sales..............................................................................(1)-(1)

Settlements.........................................................................-11EndingbalanceatDecember31,2014......................................................$(1)$-$(1)Changeinunrealizedgains(losses)relatedtoassets/liabilitiesheldatDecember31,2014..............$-$2$2 Power:

BeginningbalanceatJanuary1,2014.......................................................$19$(108)$(89)Realizedandunrealizedgains(losses)includedinregulatoryassets/liabilities:

.....................(14)(39)(53)

Purchases..........................................................................34-34 Sales..............................................................................(1)-(1)

Settlements

.........................................................................(29)5(24)EndingbalanceatDecember31,2014......................................................$9$(142)$(133)Changeinunrealizedgains(losses)relatedtoassets/liabilitiesheldatDecember31,2014..............$-$(43)$(43)Uranium:

BeginningbalanceatJanuary1,2014.......................................................$(6)$(a)$(6)Realizedandunrealizedgains(losses)includedinregulatoryassets/liabilities:.....................(1)(a)(1)

Settlements.........................................................................5(a)5EndingbalanceatDecember31,2014......................................................$(2)$(a)$(2)Changeinunrealizedgains(losses)relatedtoassets/liabilitiesheldatDecember31,2014..............$(1)$(a)$(1)(a)Notapplicable.

110 TransfersintooroutofLevel3representeither(1)existingassetsandliabilitiesthatwerepreviouslycategorizedasahigherlevel,butwererecategorizedtoLevel3becausetheinputstothemodelbecameunobservableduringtheperiod,or(2)existingassetsandliabilitiesthatwerepreviouslyclassifiedasLevel3,butwererecategorizedtoahigherlevelbecausethe lowestsignificantinputbecameobservableduringtheperiod.TransfersbetweenLevel1andLevel3forfueloilsandbetween Level2andLevel3forpowerderivativeswereprimarilycausedbychangesinavailabilityofsimilarfinancialtradesobservable onelectronicexchangesbetweentheperiods.AnyreclassificationsarereportedastransfersoutofLevel3atthefairvalue measurementreportedatthebeginningoftheperiodinwhichthechangesoccur.SeeNote11-RetirementBenefitsforthefairvaluehierarchytablesdetailingAmeren'spensionandpostretirementplanassetsasofDecember31,2015,aswellasatablesummarizingthechangesinLevel3planassetsduring2015.TheAmerenCompanies'carryingamountsofcashandcashequivalentsapproximatefairvaluebecauseoftheshort-termnatureoftheseinstruments.TheyareconsideredtobeLevel1inthefairvaluehierarchy.TheAmerenCompanies'short-term borrowingsalsoapproximatefairvaluebecauseoftheirshort-termnature.Short-termborrowingsareconsideredtobe Level2inthefairvaluehierarchyastheyarevaluedbasedonmarketratesforsimilarmarkettransactions.Theestimatedfair valueoflong-termdebtandpreferredstockisbasedonthequotedmarketpricesforsameorsimilarissuancesforcompanies withsimilarcreditprofilesoronthecurrentratesofferedtotheAmerenCompaniesforsimilarfinancialinstruments,whichfair valuemeasurementisconsideredLevel2inthefairvaluehierarchy.Thefollowingtablepresentsthecarryingamountsandestimatedfairvaluesofourlong-termdebt,capitalleaseobligationsandpreferredstockatDecember31,2015and2014:

2015 2014CarryingAmountFairValueCarryingAmountFairValue Ameren: (a)Long-termdebtandcapitalleaseobligations(includingcurrentportion)(b)...$7,275$7,814$6,205$7,135Preferredstock

.................................................142125142122AmerenMissouri:Long-termdebtandcapitalleaseobligations(includingcurrentportion)(b)...$4,110$4,449$3,981$4,518Preferredstock

.................................................80758073AmerenIllinois:

Long-termdebt(includingcurrentportion)(b)..........................$2,471$2,665$2,224$2,517Preferredstock

.................................................62506249(a)Preferredstockisrecordedin"NoncontrollingInterests"ontheconsolidatedbalancesheet.

(b)Carryingamountsreflecttheadoptionofthenewauthoritativeaccountingguidanceforthepresentationofdebtissuancecosts.SeeNote1-SummaryofSignificantAccountingPoliciesNOTE9-NUCLEARDECOMMISSIONINGTRUSTFUND INVESTMENTSAmerenMissourihasinvestmentsindebtandequitysecuritiesthatareheldinatrustfundforthepurposeoffundingthedecommissioningofitsCallawayenergycenter.

Wehaveclassifiedtheseinvestmentsasavailableforsale, andwehaverecordedallsuchinvestmentsattheirfair marketvalueatDecember31,2015,and2014.See Note10-CallawayEnergyCenterforadditional

information.Investmentsinthenucleardecommissioningtrustfundhaveatargetallocationof60%to70%inequity securities,withthebalanceinvestedindebtsecurities.ThefollowingtablepresentsproceedsfromthesaleandmaturitiesofinvestmentsinAmerenMissouri'snuclear decommissioningtrustfundandthegrossrealizedgains andlossesresultingfromthosesalesfortheyearsended December31,2015,2014,and2013:201520142013Proceedsfromsalesandmaturities..$349$391$196Grossrealizedgains

..............

8 77Grossrealizedlosses

..............

2 25Netrealizedandunrealizedgainsandlossesaredeferredandrecordedasaregulatoryassetoraregulatory liabilityonAmeren'sandAmerenMissouri'sbalancesheets.

Thisreportingisconsistentwiththemethodusedto accountforthedecommissioningcostsrecoveredinrates.

Gainsorlossesassociatedwithassetsinthetrustfund couldresultinlowerorhigherfundingrequirementsfor decommissioningcosts,whichareexpectedtobereflected inelectricratespaidbyAmerenMissouri'scustomers.See Note2-RateandRegulatoryMatters.

111 ThefollowingtablepresentsthecostsandfairvaluesofinvestmentsindebtandequitysecuritiesinAmeren'sandAmerenMissouri'snucleardecommissioningtrustfundatDecember31,2015and2014:SecurityTypeCostGrossUnrealizedGainGrossUnrealizedLossFairValue 2015Debtsecurities

....................................$191$2$4$189Equitysecurities

..................................

147 224 7 364 Cash...........................................4--4 Other (a).........................................(1)--(1)Total...........................................$341$226$11$556 2014 Debtsecurities....................................$175$7$-$182Equitysecurities..................................1382304364 Cash...........................................1--1 Other (a).........................................2

--2 Total...........................................$316$237$4$549(a)Representspayablesrelatingtopendingsecuritypurchases,netofreceivablesrelatedtopendingsecuritysalesandinterest.ThefollowingtablepresentsthecostsandfairvaluesofinvestmentsindebtsecuritiesinAmeren'sandAmerenMissouri'snucleardecommissioningtrustfundaccordingtotheircontractualmaturitiesatDecember31,2015:

Cost Fair ValueLessthan5years......................................................................................$106$1055yearsto10years.....................................................................................4241Dueafter10years......................................................................................4343 Total................................................................................................$191$189Wehaveunrealizedlossesrelatingtocertainavailable-for-saleinvestmentsincludedinournucleardecommissioningtrustfund,recordedasaregulatoryassetasdiscussedabove.Decommissioningwillnotoccuruntilournuclearenergycenterisretired.AmerenMissourireceivedalicenseextensionfromtheNRCinMarch2015toextendtheCallawayenergycenter's operatinglicenseto2044.Thefollowingtablepresentsthefairvalueandthegrossunrealizedlossesoftheavailable-for-sale securitiesheldinAmeren'sandAmerenMissouri'snucleardecommissioningtrustfund.Theyareaggregatedbyinvestment categoryandthelengthoftimethatindividualsecuritieshavebeeninacontinuousunrealizedlosspositionatDecember31, 2015:Lessthan12Months12MonthsorGreater TotalFairValue Gross UnrealizedLossesFairValue Gross UnrealizedLossesFairValue Gross Unrealized LossesDebtsecurities.....................................$136$3$4$1$140$4Equitysecurities....................................16344207 Total.............................................$152$6$8$5$160$11NOTE10-CALLAWAYENERGYCENTERUndertheNWPA,theDOEisresponsiblefordisposingofspentnuclearfuelfromtheCallawayenergycenterand othercommercialnuclearenergycenters.UndertheNWPA, AmerenMissouriandotherownersofnuclearenergy centersareresponsibleforpayingthedisposalcosts.The NWPAestablishedthefeethattheseutilitiespaythefederal governmentfordisposingofthespentnuclearfuelatone mill,orone-tenthofonecent,foreachkilowatthour generatedandsoldbythoseplants.TheNWPAalso requirestheDOEtoreviewthenuclearwastefeeannually againstthecostofthenuclearwastedisposalprogramand toproposetotheUnitedStatesCongressanyfee adjustmentnecessarytooffsetthecostsoftheprogram.As requiredbytheNWPA,AmerenMissouriandotherutilities haveenteredintostandardcontractswiththeDOE.ConsistentwiththeNWPAanditsstandardcontract, AmerenMissourihadhistoricallycollectedonemillfromits electriccustomersforeachkilowatthourofelectricitythatit generatedandsoldfromitsCallawayenergycenter.

Becausethefederalgovernmentisnotmeetingitsdisposal obligation,thecollectionofthisfeeiscurrentlysuspended.AlthoughboththeNWPAandthestandardcontractstatedthattheDOEwouldbegintodisposeofspentnuclear fuelby1998,theDOEisnotmeetingitsdisposalobligation.

TheDOE'sdelayincarryingoutitsobligationtodisposeof spentnuclearfuelfromtheCallawayenergycenterisnot expectedtoadverselyaffectthecontinuedoperationsofthe energycenter.AmerenMissourihassufficientcapacityinthe spentfuelpoolanddryspentstoragefacilityattheCallaway energycentertostoreitsspentnuclearfuelgeneratedthrough theendoftheenergycenter'soperatinglicensein2044.

112 AsaresultoftheDOE'sfailuretobegintodisposeofspentnuclearfuelfromcommercialnuclearenergycentersandfulfillitscontractualobligations,AmerenMissouriand othernuclearenergycenterownerssuedtheDOEto recovercosts,suchascertainNRCfeesandMissouriad valoremtaxes,incurredforongoingstorageoftheirspent fuel.Thelawsuitresultedinasettlementagreementthat providesforannualrecoveryofadditionalspentfuelstorage andrelatedcostsincurredfrom2010through2016,with theabilitytoextendtherecoveryperiodasmutuallyagreed uponbytheparties.Includedinthesereimbursementsare costsrelatedtothedryspentfuelstoragefacilityatthe Callawayenergycenter,towhichAmerenMissouribegan transferringspentfuelassembliesin2015.Ameren Missouriwillcontinuetoapplyforreimbursementfromthe DOEforallowablecostsassociatedwiththeongoing storageofspentfuel.ElectricutilityrateschargedtocustomersprovidefortherecoveryoftheCallawayenergycenter's decommissioningcosts,whichincludedecontamination, dismantling,andsiterestorationcosts,overtheexpected lifeofthenuclearenergycenter.Amountscollectedfrom customersaredepositedintotheexternalnuclear decommissioningtrustfundtoprovidefortheCallaway energycenter'sdecommissioning.Itisassumedthatthe Callawayenergycentersitewillbedecommissioned throughtheimmediatedismantlementmethodand removedfromservice.AmerenandAmerenMissourihave recordedanAROfortheCallawayenergycenter decommissioningcostsatfairvalue,whichrepresentsthe presentvalueofestimatedfuturecashoutflows.Annual decommissioningcostsof$7millionareincludedinthe costsusedtoestablishelectricratesforAmerenMissouri's customers.Everythreeyears,theMoPSCrequiresAmeren Missouritofileanupdatedcoststudyandfundinganalysis fordecommissioningitsCallawayenergycenter.Following theNRC'sdecisioninMarch2015toextendtheCallaway energycenter'soperatinglicensefrom2024to2044,an updatedcoststudyandarevisedfundinganalysiswerefiled withtheMoPSCinApril2015.AmerenMissouri'sApril 2015filingsupportednochangeinelectricserviceratesfor decommissioningcosts.Thereisnotimerequirementby whichtheMoPSCmustissueanorderregardingthe decommissioningcostincludedinAmerenMissouri's electricservicerates.Iftheassumedreturnontrustassets isnotearned,webelievethatitisprobablethatanysuch earningsdeficiencywillberecoveredinrates.Thefairvalue ofthetrustfundforAmerenMissouri'sCallawayenergy centerisreportedas"Nucleardecommissioningtrustfund" inAmeren'sandAmerenMissouri'sbalancesheets.This amountislegallyrestrictedandmaybeusedonlytofund thecostsofnucleardecommissioning.Changesinthefair valueofthetrustfundarerecordedasanincreaseor decreasetothenucleardecommissioningtrustfund,with anoffsettingadjustmenttotherelatedregulatoryliability.SeeNote2-RateandRegulatoryMattersandNote9-NuclearDecommissioningTrustFundInvestmentsfor additionalinformationrelatedtotheCallawayenergycenter.NOTE11-RETIREMENTBENEFITSTheprimaryobjectiveoftheAmerenpensionandpostretirementbenefitplansistoprovideeligibleemployeeswithpensionandpostretirementhealthcareandlife insurancebenefits.Amerenoffersdefinedbenefitpension andpostretirementbenefitplanscoveringsubstantiallyall ofitsunionemployees.Amerenoffersdefinedbenefit pensionplanscoveringsubstantiallyallofitsnon-union employeesandpostretirementbenefitplanscoveringnon-unionemployeeshiredbeforeOctober2015.Amerenusesa measurementdateofDecember31foritspensionand postretirementbenefitplans.AmerenMissouriandAmeren IllinoiseachparticipateinAmeren'ssingle-employer pensionandotherpostretirementplans.Ameren'squalified pensionplanistheAmerenRetirementPlan.Amerenalso hasanunfundednonqualifiedpensionplan,theAmeren SupplementalRetirementPlan,whichisavailabletoprovide certainmanagementemployeesandretireeswitha supplementalbenefitwhentheirqualifiedpensionplan benefitsarecappedincompliancewithInternalRevenue Codelimitations.Ameren'sotherpostretirementplansare theAmerenRetireeMedicalPlanandtheAmerenGroup LifeInsurancePlan.OnlyAmerensubsidiariesparticipatein theplanslistedabove.InDecember2013,AmerencompletedthedivestitureofNewAERtoIPH.Inaccordancewiththetransaction agreement,Amerenretainedthepensionobligationsasof December2,2013,associatedwiththecurrentandformer employeesofNewAERanditssubsidiarieswhowere includedintheAmerenRetirementPlanandtheAmeren SupplementalRetirementPlan.Amerenalsoretainedthe postretirementbenefitobligationsassociatedwiththe employeesofNewAERanditssubsidiarieswhowere eligibletoretireatDecember2,2013,andwhowere includedintheAmerenRetireeMedicalPlanandthe AmerenGroupLifeInsurancePlan.Ameren'sunfundedobligationunderitspensionandotherpostretirementbenefitplanswas$567millionand

$710millionasofDecember31,2015,andDecember31, 2014,respectively.Thesenetliabilitiesarerecordedin "Othercurrentliabilities,""Pensionandother postretirementbenefits,"and"Otherassets"onAmeren's consolidatedbalancesheet.Theprimaryfactorcontributing tothedecreaseintheunfundedobligationduring2015was a50basispointincreaseinthepensionandother postretirementbenefitplandiscountratesusedto determinethepresentvalueoftheobligation.Thedecrease intheunfundedobligationalsoresultedinadecreaseto "Regulatoryassets"onAmeren's,AmerenMissouri's,and AmerenIllinois'consolidatedbalancesheet.ThefollowingtablepresentsthenetbenefitliabilityrecordedonthebalancesheetsofeachoftheAmeren CompaniesasofDecember31,2015and2014:20152014 Ameren (a).............................$567$710AmerenMissouri

........................

236 277AmerenIllinois

.........................

219 278(a)IncludesamountsforAmerenregistrantandnonregistrantsubsidiaries.

113 Amerenrecognizestheunderfundedstatusofitspensionandpostretirementplansasaliabilityonitsconsolidatedbalancesheet,withoffsettingentriestoaccumulatedOCIandregulatoryassets,inaccordancewithauthoritativeaccountingguidance.ThefollowingtablepresentsthefundedstatusofAmeren'spensionandpostretirementbenefitplansasofDecember31,2015and2014.ItalsoprovidestheamountsincludedinregulatoryassetsandaccumulatedOCIat December31,2015and2014,thathavenotbeenrecognizedinnetperiodicbenefitcosts.

2015 2014PensionBenefits (a)Postretirement Benefits (a)PensionBenefits (a)Postretirement Benefits (a)Accumulatedbenefitobligationatendofyear

...............$3,995$(b)$4,176$(b)Changeinbenefitobligation:Netbenefitobligationatbeginningofyear

................$4,410$1,203$3,900$1,096Servicecost

.......................................

92 24 79 19Interestcost

.......................................

174 48 183 50Participantcontributions

.............................. 1 6Actuarial(gain)loss

.................................

(256)(133)462 84 Settlement

........................................

(2)---Benefitspaid

.......................................

(221)(56)(214)(65)Federalsubsidyonbenefitspaid

........................(b)-(b)3Netbenefitobligationatendofyear

.......................

4,197 1,094 4,410 1,203Changeinplanassets:Fairvalueofplanassetsatbeginningofyear

..............

3,794 1,109 3,461 1,074Actualreturnonplanassets

...........................

(29)(8)448 75Employercontributions

...............................

111 18 99 6Federalsubsidyonbenefitspaid

........................(b)-(b)3Participantcontributions

.............................. 1 6 Settlements

........................................

(2)---Benefitspaid

.......................................

(221)(56)(214)(65)Fairvalueofplanassetsatendofyear

.....................

3,653 1,071 3,794 1,109Fundedstatus-deficiency

..............................

544 23 616 94AccruedbenefitcostatDecember31

......................$544$23$616$94Amountsrecognizedinthebalancesheetconsistof:Noncurrentasset (c)..................................$-$(18)$-$-Currentliability (d)...................................

32 32Noncurrentliability

..................................

541 39 613 92Netliabilityrecognized

...............................$544$23$616$94Amountsrecognizedinregulatoryassetsconsistof:Netactuarial(gain)loss

..............................$395$(82)$452$(7)Priorservicecost(credit)

.............................(5)(11)(6)(16)Amounts(pretax)recognizedinaccumulatedOCIconsistof:Netactuarial(gain)loss

..............................17(3)29(5)Priorservicecost(credit)

.............................

---(1)Total.............................................$407$(96)$475$(29)(a)IncludesamountsforAmerenregistrantandnonregistrantsubsidiaries.(b)Notapplicable.

(c)Includedin"Otherassets"onAmeren'sconsolidatedbalancesheet.

(d)Includedin"Othercurrentliabilities"onAmeren'sconsolidatedbalancesheet.ThefollowingtablepresentstheassumptionsusedtodetermineourbenefitobligationsatDecember31,2015and2014:PensionBenefitsPostretirementBenefits2015201420152014Discountrateatmeasurementdate

...........................................

4.50%4.00%4.50%4.00%Increaseinfuturecompensation

.............................................

3.50 3.50 3.50 3.50Medicalcosttrendrate(initial)

..............................................(a)(a)5.00 5.00Medicalcosttrendrate(ultimate)

............................................(a)(a)5.00 5.00Yearstoultimaterate

.....................................................(a)(a)--(a)Notapplicable 114 Amerendeterminesdiscountrateassumptionsbyidentifyingatheoreticalsettlementportfolioofhigh-qualitycorporatebondssufficienttoprovideforaplan'sprojected benefitpayments.Thesettlementportfolioofbondsis selectedfromapoolofmorethan700high-quality corporatebonds.Asinglediscountrateisthendetermined; thatrateresultsinadiscountedvalueoftheplan'sbenefit paymentsthatequatestothemarketvalueoftheselected bonds.Inaddition,during2015,Amerenadoptedthe SocietyofActuaries2015MortalityTablesReportand MortalityImprovementScale.Theupdatedmortalitytables assumealowerrateofmortalityimprovementascompared tothe2014MortalityTablesReportandMortality ImprovementScalethatAmerenadoptedin2014.The2015 tablesloweredprojectedimprovementsinlifeexpectancies forouremployeesandretirees,resultinginadecreaseto ourpensionandotherpostretirementbenefitobligations.

FundingPensionbenefitsarebasedontheemployees'yearsofservice,age,andcompensation.Ameren'spensionplansarefundedincompliancewithincometaxregulations, federalfunding,andotherregulatoryrequirements.Asa result,Amerenexpectstofunditspensionplanatalevel equaltothegreaterofthepensionexpenseorthelegally requiredminimumcontribution.Consideringits assumptionsatDecember31,2015,itsinvestment performancein2015,anditspensionfundingpolicy, Amerenexpectstomakeannualcontributionsof

$40millionto$70millionineachofthenextfiveyears, withaggregateestimatedcontributionsof$280million.We expectAmerenMissouri'sandAmerenIllinois'portionof thefuturefundingrequirementstobe40%and50%,

respectively.Theseamountsareestimates.Theymay changebasedonactualinvestmentperformance,changes ininterestrates,changesinourassumptions,changesin governmentregulations,andanyvoluntarycontributions.

Ourfundingpolicyforpostretirementbenefitsisprimarily tofundtheVoluntaryEmployeeBeneficiaryAssociation (VEBA)truststomatchtheannualpostretirementexpense.Thefollowingtablepresentsthecashcontributionsmadetoourdefinedbenefitretirementplanandtoour postretirementplansduring2015,2014,and2013:PensionBenefitsPostretirementBenefits201520142013201520142013AmerenMissouri...$47$41$60$8$3$10AmerenIllinois

....453950 8211 Other............

191946 2 14 Ameren (a).........11199156 18625(a)IncludesamountsforAmerenregistrantandnonregistrant subsidiaries.InvestmentStrategyandPoliciesAmerenmanagesplanassetsinaccordancewiththe"prudentinvestor"guidelinescontainedinERISA.The investmentcommittee,whichincludesmembersofsenior management,approvesandimplementsinvestment strategyandassetallocationguidelinesfortheplanassets.

Theinvestmentcommittee'sgoalsaretwofold:first,to ensurethatsufficientfundsareavailabletoprovidethe benefitsatthetimetheyarepayable;andsecond,to maximizetotalreturnonplanassetsandtominimize expensevolatilityconsistentwithitstoleranceforrisk.

Amerendelegatesthetaskofinvestmentmanagementto specialistsineachassetclass.Asappropriate,Ameren provideseachinvestmentmanagerwithguidelinesthat specifyallowableandprohibitedinvestmenttypes.The investmentcommitteeregularlymonitorsmanager performanceandcompliancewithinvestmentguidelines.Theexpectedreturnonplanassetsassumptionisbasedonhistoricalandprojectedratesofreturnforcurrent andplannedassetclassesintheinvestmentportfolio.

Projectedratesofreturnforeachassetclasswere estimatedafterananalysisofhistoricalexperience,future expectations,andthevolatilityofthevariousassetclasses.

Afterconsideringthetargetassetallocationforeachasset class,weadjustedtheoverallexpectedrateofreturnforthe portfolioforhistoricalandexpectedexperienceofactive portfoliomanagementresultscomparedwithbenchmark returnsandfortheeffectofexpensespaidfromplanassets.

Amerenwilluseanexpectedreturnonplanassetsforits pensionandpostretirementplanassetsof7.00%,in2016.

NoplanassetsareexpectedtobereturnedtoAmeren during2016.

115 Ameren'sinvestmentcommitteestrivestoassembleaportfolioofdiversifiedassetsthatdoesnotcreateasignificantconcentrationofrisks.Theinvestmentcommitteedevelopsassetallocationguidelinesbetweenassetclasses,anditcreatesdiversificationthroughinvestmentsinassetsthatdifferbytype(equity,debt,realestate,privateequity),duration,market capitalization,country,style(growthorvalue)andindustry,amongotherfactors.Thediversificationofassetsisdisplayedin thetargetallocationtablebelow.Theinvestmentcommitteealsoroutinelyrebalancestheplanassetstoadheretothe diversificationgoals.Theinvestmentcommittee'sstrategyreducestheconcentrationofinvestmentrisk;however,Amerenis stillsubjecttooverallmarketrisk.Thefollowingtablepresentsourtargetallocationsfor2016andourpensionand postretirementplans'assetcategoriesasofDecember31,2015and2014:

Asset CategoryTargetAllocation 2016PercentageofPlanAssetsatDecember31, 2015 2014PensionPlan:Cashandcashequivalents........................................0%-5%

1%2%Equitysecurities:U.S.large-capitalization........................................29%-39%

34%34%U.S.small-andmid-capitalization................................3%-13%

7%7%Internationalandemergingmarkets...............................9%-19%

13%12%Totalequity....................................................51%-61%

54%53%Debtsecurities.................................................35%-45%

40%41%Realestate....................................................0%-9%

5%4%Privateequity..................................................0%-5%(a)(a)Total.........................................................

100%100%PostretirementPlans:

Cashandcashequivalents........................................0%-7%

4%4%Equitysecurities:U.S.large-capitalization........................................34%-44%

39%40%U.S.small-andmid-capitalization................................2%-12%

7%7%International.................................................9%-19%

13%13%Totalequity....................................................55%-65%

59%60%Debtsecurities.................................................33%-43%

37%36%Total.........................................................

100%100%(a)Lessthan1%ofplanassets.Ingeneral,theUnitedStateslarge-capitalizationequityinvestmentsarepassivelymanagedorindexed,whereastheinternational,emergingmarkets,UnitedStatessmall-capitalization,andUnitedStatesmid-capitalizationequityinvestmentsareactivelymanagedbyinvestmentmanagers.Debtsecuritiesincludeabroadrangeoffixed-incomevehicles.Debtsecurityinvestmentsinhigh-yieldsecurities,emergingmarketsecurities,andnon-United-States-dollar-denominatedsecuritiesare ownedbytheplans,butinlimitedquantitiestoreducerisk.Mostofthedebtsecurityinvestmentsareunderactive managementbyinvestmentmanagers.Realestateinvestmentsincludeprivaterealestatevehicles;however,Amerendoesnot,bypolicy,holddirectinvestmentsinrealestateproperty.Ameren'sinvestmentinprivateequityfundsisspreadamongeight differentlimitedpartnerships,withinvestedcapitalrangingfromlessthan$1millionto$4millionineach,whichinvest primarilyinadiversifiednumberofsmallUnitedStates-basedcompanies.Amerenisseekingtoeliminateitsprivateequity investmentsovertime.Additionally,Ameren'sinvestmentcommitteeallowsinvestmentmanagerstousederivatives,suchas indexfutures,exchangetradedfunds,foreignexchangefutures,andoptions,incertainsituations,toincreaseortoreduce marketexposureinanefficientandtimelymanner.FairValueMeasurementsofPlanAssetsInvestmentsinthepensionandpostretirementbenefitplanswerestatedatfairvalueasofDecember31,2015.Thefairvalueofanassetistheamountthatwouldbereceiveduponitssaleinanorderlytransactionbetweenmarketparticipantsatthemeasurementdate.Cashandcashequivalentshaveinitialmaturitiesofthreemonthsorlessandarerecordedatcostplus accruedinterest.Thecarryingamountsofcashandcashequivalentsapproximatefairvaluebecauseoftheshort-termnature oftheseinstruments.Investmentstradedinactivemarketsonnationalorinternationalsecuritiesexchangesarevaluedat closingpricesonthelastbusinessdayonorbeforethemeasurementdate.Securitiestradedinover-the-countermarketsare valuedbasedonquotedmarketprices,brokerordealerquotations,oralternativepricingsourceswithreasonablelevelsof pricetransparency.Investmentsmeasuredundernetassetvaluationarebasedonthefairvaluesoftheunderlyingassets providedbythefundsandtheiradministrators.Derivativecontractsarevaluedatfairvalue,asdeterminedbytheinvestment managers(orindependentthirdpartiesonbehalfoftheinvestmentmanagers),whouseproprietarymodelsandtakeinto considerationexchangequotationsonunderlyinginstruments,dealerquotations,andothermarketinformation.Thefairvalue ofrealestateisbasedonannualappraisalreportspreparedbyanindependentrealestateappraiser.

116 Thefollowingtablesetsforth,bylevelwithinthefairvaluehierarchydiscussedinNote8-FairValueMeasurements,thepensionplanassetsmeasuredatfairvalueasofDecember31,2015:QuotedPricesinActiveMarketsforIdentifiedAssets(Level1)SignificantOtherObservableInputs(Level2)SignificantOther Unobservable Inputs(Level3)TotalCashandcashequivalents..................................$-$20$-$20Equitysecurities:U.S.large-capitalization..................................-1,296-1,296U.S.small-andmid-capitalization..........................268--268Internationalandemergingmarkets........................122369-491Debtsecurities:Corporatebonds.......................................-631-631Municipalbonds.......................................-104-104U.S.Treasuryandagencysecurities........................6751-757 Other................................................-5-5Realestate..............................................--168168Privateequity............................................--88 Total..................................................$396$3,176$176$3,748Less:MedicalbenefitassetsatDecember31 (a)..................

(123)Plus:NetreceivablesatDecember31 (b)........................28Fairvalueofpensionplansassetsatyearend...................$

3,653(a)Medicalbenefit(healthandwelfare)componentforaccountsmaintainedinaccordancewithSection401(h)oftheInternalRevenueCodetofundaportionofthepostretirementobligation.(b)Receivablesrelatedtopendingsecuritysales,offsetbypayablesrelatedtopendingsecuritypurchases.Thefollowingtablesetsforth,bylevelwithinthefairvaluehierarchydiscussedinNote8-FairValueMeasurements,thepensionplanassetsmeasuredatfairvalueasofDecember31,2014:QuotedPricesinActiveMarketsforIdentifiedAssetsorLiabilities(Level1)SignificantOtherObservableInputs(Level2)SignificantOther Unobservable Inputs(Level3)TotalCashandcashequivalents..................................$-$38$-$38Equitysecurities:U.S.large-capitalization..................................-1,331-1,331U.S.small-andmid-capitalization..........................270--270Internationalandemergingmarkets........................134360-494Debtsecurities:Corporatebonds.......................................-1,026-1,026Municipalbonds.......................................-175-175U.S.Treasuryandagencysecurities........................6366-372 Other................................................-31-31Realestate..............................................--147147Privateequity............................................--1313Derivativeassets.........................................1--1 Total..................................................$411$3,327$160$3,898Less:MedicalbenefitassetsatDecember31 (a)..................

(125)Plus:NetreceivablesatDecember31 (b)........................21Fairvalueofpensionplansassetsatyearend...................$

3,794(a)Medicalbenefit(healthandwelfare)componentforaccountsmaintainedinaccordancewithSection401(h)oftheInternalRevenueCodetofundaportionofthepostretirementobligation.(b)Receivablesrelatedtopendingsecuritysales,offsetbypayablesrelatedtopendingsecuritypurchases.

117 ThefollowingtablesummarizesthechangesinthefairvalueofthepensionplanassetsclassifiedasLevel3inthefairvaluehierarchyforeachoftheyearsendedDecember31,2015and2014:

BeginningBalanceatJanuary1,ActualReturnonPlanAssetsRelatedtoAssetsStillHeldattheReportingDateActualReturnonPlanAssetsRelatedtoAssetsSoldDuringthePeriod Purchases,Sales,andSettlements,Net Net Transfersinto(outof)ofLevel3EndingBalanceatDecember31, 2015:Realestate

............$147$14$-$7$-$168Privateequity

..........

13 (9)9 (5)-8 2014:

Realestate............$131$11$-$5$-$147Privateequity..........15(9)10(3)-13Thefollowingtablesetsforth,bylevelwithinthefairvaluehierarchydiscussedinNote8-FairValueMeasurements,thepostretirementbenefitplansassetsmeasuredatfairvalueasofDecember31,2015:QuotedPricesinActiveMarketsforIdentifiedAssets(Level1)SignificantOtherObservableInputs(Level2)SignificantOther Unobservable Inputs(Level3)TotalCashandcashequivalents..................................$61$-$-$61Equitysecurities:U.S.large-capitalization..................................27298-370U.S.small-andmid-capitalization..........................65--65 International...........................................3393-126 Other.................................................-7-7Debtsecurities:Corporatebonds........................................-138-138Municipalbonds........................................-114-114U.S.Treasuryandagencysecurities.........................-55-55 Other.................................................-40-40 Total...................................................$431$545$-$976Plus:MedicalbenefitassetsatDecember31 (a)...................123Less:NetpayablesatDecember31 (b)..........................

(28)Fairvalueofpostretirementbenefitplansassetsatyearend........$1,071(a)Medicalbenefit(healthandwelfare)componentfor401(h)accountstofundaportionofthepostretirementobligation.These401(h)assetsareincludedinthepensionplanassetsshownabove.(b)Payablesrelatedtopendingsecuritypurchases,offsetbyinterestreceivablesandreceivablesrelatedtopendingsecuritysales.Thefollowingtablesetsforth,bylevelwithinthefairvaluehierarchydiscussedinNote8-FairValueMeasurements,thepostretirementbenefitplansassetsmeasuredatfairvalueasofDecember31,2014:QuotedPricesinActiveMarketsforIdentifiedAssets(Level1)SignificantOtherObservableInputs(Level2)SignificantOther Unobservable Inputs(Level3)TotalCashandcashequivalents..................................$89$-$-$89Equitysecurities:U.S.large-capitalization..................................291101-392U.S.small-andmid-capitalization...........................70

--70 International...........................................3794-131 Other................................................. 7Debtsecurities:Corporatebonds

........................................

-105-105Municipalbonds

........................................

-111-111U.S.Treasuryandagencysecurities

......................... 89 Other................................................. 44 Total...................................................$487$551$-

$1,038Plus:MedicalbenefitassetsatDecember31 (a)...................125Less:NetpayablesatDecember31 (b)..........................

(54)Fairvalueofpostretirementbenefitplansassetsatyearend........$1,109(a)Medicalbenefit(healthandwelfare)componentfor401(h)accountstofundaportionofthepostretirementobligation.These401(h)assetsareincludedinthepensionplanassetsshownabove.(b)Payablesrelatedtopendingsecuritypurchases,offsetbyMedicare,interestreceivables,andreceivablesrelatedtopendingsecuritysales.

118 NetPeriodicBenefitCostThefollowingtablepresentsthecomponentsofthenetperiodicbenefitcostofAmeren'spensionandpostretirementbenefitplansduring2015,2014,and2013:PensionBenefits (a)PostretirementBenefits (a)2015Servicecost

...................................................................$92$24Interestcost

...................................................................17448Expectedreturnonplanassets

.....................................................(248)(68)Amortizationof:Priorservicecredit

............................................................(1)(5)Actuarialloss

................................................................745SettlementLoss

................................................................

1-Netperiodicbenefitcost

..........................................................$92$4 2014 Servicecost...................................................................$79$19Interestcost...................................................................18350Expectedreturnonplanassets

.....................................................(229)(65)Amortizationof:Priorservicecredit............................................................(1)(5)Actuarial(gain)loss...........................................................49(7)Netperiodicbenefitcost(benefit)...................................................$81$(8) 2013 Servicecost...................................................................$91$22Interestcost...................................................................16346Expectedreturnonplanassets

.....................................................(218)(62)Amortizationof:Priorservicecredit............................................................(2)(6)Actuarialloss................................................................878Curtailmentgain

..............................................................(12)(7)Netperiodicbenefitcost (b)........................................................$109$1(a)IncludesamountsforAmerenregistrantandnonregistrantsubsidiaries.

(b)Thenetperiodicbenefitcostincludesa$6millionanda$7millionnetgainforpensionbenefitsandpostretirementbenefits,respectively,whichwasincludedin"Income(loss)fromdiscontinuedoperations,netoftaxes"onAmeren'sconsolidatedstatementofincome(loss).This netgainincludesthecurtailmentgainrecognizedin2013asaresultofasignificantreductioninemployeesasoftheDecember2,2013closing dateoftheNewAERdivestiture.SeeNote16-DivestitureTransactionsandDiscontinuedOperationsforadditionalinformationonthe

divestiture.TheestimatedamountsthatwillbeamortizedfromregulatoryassetsandaccumulatedOCIintoAmeren'snetperiodicbenefitcostin2016areasfollows:PensionBenefits (a)PostretirementBenefits (a)Regulatoryassets:Priorservicecredit............................................................$(1)$(4)Netactuarialloss.............................................................46(3)AccumulatedOCI:Netactuarial(gain)loss........................................................(3)(2)

Total.........................................................................$42$(9)(a)IncludesamountsforAmerenregistrantandnonregistrantsubsidiaries.

119 Priorservicecostisamortizedonastraight-linebasisovertheaveragefutureserviceofactiveparticipantsbenefitingundertheplanamendment.Thenetactuarial(gain)losssubjecttoamortizationisamortizedonastraight-linebasisover10years.TheAmerenCompaniesareresponsiblefortheirshareofthepensionandpostretirementbenefitcosts.Thefollowingtablepresentsthepensioncostsandthepostretirementbenefitcostsincurredandincludedincontinuingoperationsforthe yearsendedDecember31,2015,2014,and2013:PensionCostsPostretirementCosts201520142013201520142013AmerenMissouri (a)...................................$54$50$69$8$3$8AmerenIllinois

......................................

383041 (3)(9)-Other..............................................

-15 (1)(2)-Ameren (b)..........................................

9281115 4(8)8(a)DoesnotincludetheimpactoftheregulatorytrackingmechanismforthedifferencebetweenthelevelofpensionandpostretirementbenefitcostsincurredbyAmerenMissouriunderGAAPandthelevelofsuchcostsincludedinrates.(b)IncludesamountsforAmerenregistrantandnonregistrantsubsidiaries.Theexpectedpensionandpostretirementbenefitpaymentsfromqualifiedtrustandcompanyfunds,whichreflectexpectedfutureservice,asofDecember31,2015,areasfollows:PensionBenefitsPostretirementBenefitsPaidfrom QualifiedTrustFundsPaidfrom Company FundsPaidfrom QualifiedTrustFundsPaidfrom Company Funds 2016...................................................$233$3$55$

2 2017...................................................244 358 2 2018...................................................250 360 2 2019...................................................257 362 2 2020...................................................261 365 22021-2025.............................................

1,377 13 341 12ThefollowingtablepresentstheassumptionsusedtodeterminenetperiodicbenefitcostforourpensionandpostretirementbenefitplansfortheyearsendedDecember31,2015,2014,and2013:PensionBenefitsPostretirementBenefits201520142013201520142013Discountrateatmeasurementdate

...........................

4.00%4.75%4.00%

4.00%4.75%4.00%Expectedreturnonplanassets

..............................

7.257.257.50 7.007.007.25Increaseinfuturecompensation

.............................

3.503.503.50 3.503.503.50Medicalcosttrendrate(initial)

..............................(a)(a)(a)5.005.005.00Medicalcosttrendrate(ultimate)

............................(a)(a)(a)5.005.005.00Yearstoultimaterate

.....................................(a)(a)(a)---(a)NotapplicableThetablebelowreflectsthesensitivityofAmeren'splanstopotentialchangesinkeyassumptions:PensionBenefitsPostretirementBenefitsServiceCostandInterest Cost Projected Benefit ObligationServiceCostandInterest Cost Postretirement Benefit Obligation0.25%decreaseindiscountrate...............................$(1)$130$1$370.25%increaseinsalaryscale

.................................

214--1.00%increaseinannualmedicaltrend

..........................

--3441.00%decreaseinannualmedicaltrend

.........................

--(3)(44)120 OtherAmerensponsorsa401(k)planforeligibleemployees.TheAmeren401(k)plancoveredalleligibleemployeesatDecember31,2015.Theplanallowsemployeestocontributeaportionoftheircompensationinaccordancewithspecificguidelines.Amerenmatchesapercentageoftheemployeecontributionsuptocertainlimits.Thefollowingtablepresentsthe portionofthematchingcontributiontotheAmeren401(k)planattributabletothecontinuingoperationsforeachofthe AmerenCompaniesfortheyearsendedDecember31,2015,2014,and2013:201520142013AmerenMissouri

.......................................................................$16$16$16AmerenIllinois

........................................................................

121110 Other................................................................................

1 11 Ameren (a)............................................................................

292827(a)IncludesamountsforAmerenregistrantandnonregistrantsubsidiaries.NOTE12-STOCK-BASEDCOMPENSATIONThe2014IncentivePlanisAmeren'slong-termstockcompensationplanforeligibleemployeesanddirectors.The2006IncentivePlanwasreplacedprospectivelyfornewgrantsbeginninginApril2014.The2014IncentivePlanprovidesfora maximumof8millioncommonsharestobeavailableforgranttoeligibleemployeesanddirectors.Totheextentthatthe issuanceofasharethatissubjecttoanoutstandingawardunderthe2006IncentivePlanwouldcauseAmerentoexceedthe maximumauthorizedsharesunderthe2006IncentivePlan,theissuanceofthatsharewilltakeplaceunderthe2014Incentive Plan.Thiswillreducethemaximumnumberofsharesthatmaybegrantedunderthe2014IncentivePlan.The2014Incentive Planawardsmaybestockoptions,stockappreciationrights,restrictedstock,restrictedstockunits,performanceshares,performanceshareunits,cash-basedawards,andotherstock-basedawards.AsummaryofnonvestedsharesatDecember31,2015,andchangesduringtheyearendedDecember31,2015,underthe2006IncentivePlanandthe2014IncentivePlanarepresentedbelow:PerformanceShareUnits Share Units Weighted-averageFairValueperShareUnitNonvestedatJanuary1,2015

.....................................................1,162,377$35.35 Granted (a).....................................................................570,31352.88 Forfeitures

....................................................................(1,944)34.75Earnedandvested (b)............................................................(705,876)33.93NonvestedatDecember31,2015

..................................................

1,024,870$46.08(a)Includesperformanceshareunits(shareunits)grantedtocertainexecutiveandnonexecutiveofficersandothereligibleemployeesin2015underthe2014IncentivePlan.(b)Includesshareunitsgrantedin2013thatvestedasofDecember31,2015,thatwereearnedpursuanttothetermsoftheawardgrants.Alsoincludesshareunitsthatvestedduetoattainmentofretirementeligibilitybycertainemployees.Actualsharesissuedforretirement-eligibleemployeeswillvarydependingonactualperformanceoverthethree-yearmeasurementperiod.Amerenrecordedcompensationexpenseof$19million,$19million,and$20millionfortheyearsendedDecember31,2015,2014,and2013,respectively, andarelatedtaxbenefitof$7million,$7million,and

$8millionfortheyearsendedDecember31,2015,2014, and2013,respectively.Amerensettledperformanceshare unitsof$27million,$33million,and$11millionforthe yearsendedDecember31,2015,2014,and2013.There werenosignificantcompensationcostscapitalizedrelated totheperformanceshareunitsduringtheyearsended December31,2015,2014,and2013.AsofDecember31, 2015,totalcompensationcostof$21millionrelatedto nonvestedawardsnotyetrecognizedisexpectedtobe recognizedoveraweighted-averageperiodof23months.PerformanceShareUnitsAshareunitvestsandentitlesanemployeetoreceivesharesofAmerencommonstock(plusaccumulated dividends)if,attheendofthethree-yearperformance period,certainspecifiedperformanceormarketconditions havebeenmetandiftheindividualremainsemployedby Amerenthroughtherequiredvestingperiod.Theexact numberofsharesissuedpursuanttoashareunitvaries from0%to200%ofthetargetaward,dependingonactual companyperformancerelativetotheperformancegoals.

Thevestingperiodforshareunitsawardedin2015 extendedbeyondthethree-yearperformanceperiodtothe payoutdate,whilethevestingperiodforshareunits awardedin2013and2014matchedthethree-year performanceperiod.

121 Thefairvalueofeachshareunitawardedin2015underthe2014IncentivePlanwasdeterminedtobe$52.88,whichwasbasedonAmeren'sclosingcommon sharepriceof$46.13atDecember31,2014,andlattice simulations.Latticesimulationsareusedtoestimate expectedsharepayoutbasedonAmeren'stotalshareholder returnforathree-yearperformanceperiodrelativetothe designatedpeergroupbeginningJanuary1,2015.The simulationscanproduceagreaterfairvaluefortheshare unitthantheapplicableclosingcommonshareprice becausetheyincludetheweightedpayoutscenariosin whichanincreaseinthesharepricehasoccurred.The significantassumptionsusedtocalculatefairvaluealso includedathree-yearrisk-freerateof1.10%,volatilityof 12%to18%forthepeergroup,andAmeren'sattainment ofathree-yearaverageearningspersharethresholdduring theperformanceperiod.Thefairvalueofeachshareunitawardedin2014,excludingthegrantsissuedinApril2014forcertain executiveofficers,underthe2006IncentivePlanandthe 2014IncentivePlanwasdeterminedtobe$38.90,which wasbasedonAmeren'sclosingcommonsharepriceof

$36.16atDecember31,2013,andlatticesimulations.

Latticesimulationsareusedtoestimateexpectedshare payoutbasedonAmeren'stotalshareholderreturnfora three-yearperformanceperiodrelativetothedesignated peergroupbeginningJanuary1,2014.Thesignificant assumptionsusedtocalculatefairvaluealsoincludeda three-yearrisk-freerateof0.78%,volatilityof12%to18%

forthepeergroup,andAmeren'sattainmentofathree-year averageearningspersharethresholdduringthe performanceperiod.NOTE13-INCOMETAXESThefollowingtablepresentstheprincipalreasonsforthedifferencebetweentheeffectiveincometaxrateandthestatutoryfederalincometaxratefortheyearsendedDecember31,2015,2014,and2013:AmerenMissouriAmerenIllinoisAmeren 2015Statutoryfederalincometaxrate:

.............................................35%35%35%Increases(decreases)from:Depreciationdifferences

................................................-(2)(1)Amortizationofinvestmenttaxcredit

......................................(1)-(1)Statetax............................................................355Otherpermanentitems

.................................................-(1)-Effectiveincometaxrate

....................................................37%37%38%2014 Statutoryfederalincometaxrate:.............................................35%35%35%Increases(decreases)from:Amortizationofinvestmenttaxcredit......................................(1)-(1)Statetax............................................................364Otherpermanentitems.................................................--1Effectiveincometaxrate....................................................37%41%39%

2013 Statutoryfederalincometaxrate:.............................................35%35%35%Increases(decreases)from:Depreciationdifferences................................................-(1)-Amortizationofinvestmenttaxcredit......................................(1)-(1)Statetax............................................................364Otherpermanentitems.................................................1--Effectiveincometaxrate....................................................38%40%38%

122 Thefollowingtablepresentsthecomponentsofincometaxexpense(benefit)fortheyearsendedDecember31,2015,2014,and2013:AmerenMissouriAmerenIllinoisOtherAmeren 2015Currenttaxes:

Federal.............................................$110$(83)$(29)$(2)

State...............................................17(11)(10)(4)Deferredtaxes:

Federal.............................................7119335299 State...............................................16293176Deferredinvestmenttaxcredits,amortization

..................(5)(1)-(6)Totalincometaxexpense

.................................$209$127$27$363 2014 Currenttaxes:

Federal.............................................$(13)$(51)$27$(37)

State...............................................(3)(2)(32)(37)Deferredtaxes:

Federal.............................................222159(12)369 State...............................................28382288Deferredinvestmenttaxcredits,amortization..................(5)(1)-(6)Totalincometaxexpense.................................$229$143$5$377 2013 Currenttaxes:

Federal.............................................$136$(15)$(239)(a)$(118)State...............................................4121 (43)(a)19Deferredtaxes:

Federal.............................................6499205 (a)368 State...............................................6636 (a)48Deferredinvestmenttaxcredits,amortization..................(5)(1)-(6)Totalincometaxexpense(benefit)..........................$242$110$(41)$311(a)TheseamountsaresubstantiallyrelatedtothereversalofunrecognizedtaxbenefitsasaresultofIRSguidancerelatedtothedeductibilityofexpenditurestomaintain,replace,orimprovesteamorelectricpowergenerationproperty,alongwithcasualtylossdeductionsforstorm damage.Theamountsalsoreflecttheincreaseindeferredtaxexpenseduetoavailablenetoperatinglosses.TheIllinoiscorporateincometaxratewasincreasedto9.5%fromJanuary2011throughDecember2014.Thetaxratedecreasedto7.75%onJanuary1,2015,andisscheduledtodecreaseto7.3%onJanuary1,2025.ThefollowingtablepresentsthedeferredtaxassetsanddeferredtaxliabilitiesrecordedasaresultoftemporarydifferencesatDecember31,2015and2014:AmerenMissouriAmerenIllinoisOtherAmeren 2015Accumulateddeferredincometaxes,netliability(asset):Plantrelated

.........................................$2,931$1,587$37$4,555Regulatoryassets,net

..................................81(1)-80Deferredemployeebenefitcosts

..........................(76)(40)(91)(207)Revenuerequirementreconciliationadjustments

.............-66-66Taxcarryforwards

.....................................(65)(133)(405)(603)

Other...............................................(27)120(6)Totalnetaccumulateddeferredincometaxliabilities(assets)(a)....$2,844$1,480$(439)$3,885 2014 Accumulateddeferredincometaxes,netliability(asset):Plantrelated.........................................$2,776$1,393$16$4,185Regulatoryassets,net..................................82(5)178Deferredemployeebenefitcosts

..........................(80)(45)(95)(220)Revenuerequirementreconciliationadjustments.............-66369Taxcarryforwards

.....................................(107)(139)(429)(675)

Other...............................................86(22)70134Totalnetaccumulateddeferredincometaxliabilities(assets)(a)....$2,757$1,248$(434)$3,571(a)Reflectstheadoptionofthenewauthoritativeaccountingguidanceforthebalancesheetclassificationofdeferredincometaxes.SeeNote1-SummaryofSignificantAccountingPoliciesforadditionalinformation.

123 Thefollowingtablepresentsthecomponentsofdeferredtaxassetsrelatingtonetoperatinglosscarryforwards,taxcreditcarryforwards,andcharitablecontributioncarryforwardsatDecember31,2015:

Ameren Missouri AmerenIllinoisOtherAmerenNetoperatinglosscarryforwards:

Federal (a)..............................................$35$127$245$407 State (b)...............................................

4 43846Totalnetoperatinglosscarryforwards.........................$39$131$283$453Taxcreditcarryforwards:

Federal (c)..............................................$26$1$78$105 State (d)...............................................

-14041Statevaluationallowance (e)................................

--(2)(2)Totaltaxcreditcarryforwards................................$26$2$116$144Charitablecontributioncarryforwards (f)........................$-$-$10$10Valuationallowance (e)....................................

--(4)(4)Totalcharitablecontributioncarryforwards.....................$-$-$6$6(a)Willbegintoexpirein2029.(b)Willbegintoexpirein2023.

(c)Willbegintoexpirein2029.

(d)Willbegintoexpirein2016.

(e)SeeScheduleIIunderPartIV,Item15,inthisreportforinformationonchangesinthevaluationallowance.

(f)Willbegintoexpirein2016.Thefollowingtablepresentsthecomponentsofdeferredtaxassetsrelatingtonetoperatinglosscarryforwards,taxcreditcarryforwards,andcharitablecontributioncarryforwardsatDecember31,2014:

Ameren Missouri AmerenIllinoisOtherAmerenNetoperatinglosscarryforwards:

Federal (a)..............................................$75$127$255$457 State (b)...............................................11105374Totalnetoperatinglosscarryforwards.........................$86$137$308$531Taxcreditcarryforwards:

Federal (c)..............................................$21$1$77$99 State (d)...............................................

1 23336Statevaluationallowance (e)................................(1)(1)(2)(4)Totaltaxcreditcarryforwards................................$21$2$108$131Charitablecontributioncarryforwards (f)........................$-$-$19$19Valuationallowance (e)....................................

--(6)(6)Totalcharitablecontributioncarryforwards.....................$-$-$13$13(a)Willbegintoexpirein2028 (b)Willbegintoexpirein2019.

(c)Willbegintoexpirein2029.

(d)Begantoexpirein2013.

(e)SeeScheduleIIunderPartIV,Item15,inthisreportforinformationonchangesinthevaluationallowance.

(f)Begantoexpirein2013.

124 UncertainTaxPositionsAreconciliationofthechangeintheunrecognizedtaxbenefitbalanceduringtheyearsendedDecember31,2013,2014,and2015,isasfollows:

Ameren Missouri AmerenIllinoisOtherAmerenUnrecognizedtaxbenefits-January1,2013....................$136$13$7$156Increasesbasedontaxpositionspriorto2013................-257Decreasesbasedontaxpositionspriorto2013

................(122)(16)(5)(143)Increasesbasedontaxpositionsrelatedto2013...............16-53 (a)69Changesrelatedtosettlementswithtaxingauthorities

...........


Decreasesrelatedtothelapseofstatuteoflimitations...........1--1Unrecognizedtaxbenefits-December31,2013.................$31$(1)$60$90Increasesbasedontaxpositionspriorto2014

................

1146Decreasesbasedontaxpositionspriorto2014

................(32)(1)(9)(42)Increasesbasedontaxpositionsrelatedto2014

...............


Changesrelatedtosettlementswithtaxingauthorities

...........


Increasesrelatedtothelapseofstatuteoflimitations

...........


Unrecognizedtaxbenefits-December31,2014.................$-$(1)$55$54Increasesbasedontaxpositionspriorto2015

................

-112Decreasesbasedontaxpositionspriorto2015

................--(56)(a)(56)Increasesbasedontaxpositionsrelatedto2015

...............


Changesrelatedtosettlementswithtaxingauthorities

...........


Increasesrelatedtothelapseofstatuteoflimitations

...........


Unrecognizedtaxbenefits-December31,2015

.................$-$-$-$-Totalunrecognizedtaxbenefitsthat,ifrecognized,wouldaffecttheeffectivetaxratesasofDecember31,2013...................$3$-$51 (a)$54Totalunrecognizedtaxbenefits(detriments)that,ifrecognized,wouldaffecttheeffectivetaxratesasofDecember31,2014...........$-$(1)$53 (a)$52Totalunrecognizedtaxbenefitsthat,ifrecognized,wouldaffecttheeffectivetaxratesasofDecember31,2015

...................$-$-$-$-(a)PrimarilyduetotaxpositionsrelatingtotheNewAERdivestiture.Theincomestatementimpactofthisunrecognizedtaxbenefitwasincludedin"Income(loss)fromdiscontinuedoperations,netoftaxes"onAmeren'sconsolidatedstatementofincome(loss).SeeNote16-DivestitureTransactionsandDiscontinuedOperationsforadditionalinformation.TheAmerenCompaniesrecognizeinterestcharges(income)andpenaltiesaccruedontaxliabilitiesonapretaxbasisasinterestcharges(income)ormiscellaneousexpense,respectively,inthestatementsofincome.AreconciliationofthechangeintheliabilityforinterestonunrecognizedtaxbenefitsduringtheyearsendedDecember31,2013,2014,and2015,isasfollows:

Ameren Missouri AmerenIllinoisOtherAmerenLiabilityforinterest-January1,2013.........................$8$1$(3)$6Interestcharges(income)for201 3..........................(8)(1)4(5)Liabilityforinterest-December31,2013......................$-$-$1$1Interestcharges(income)for201 4..........................

--(1)(1)Liabilityforinterest-December31,2014......................$-$-$-$-Interestcharges(income)for201 5..........................----Liabilityforinterest-December31,2015

......................$-$-$-$-AsofDecember31,2013,2014,and2015,theAmerenCompanieshaveaccruednoamountforpenaltieswithrespecttounrecognizedtaxbenefits.In2015,finalsettlementsfortaxyears2012and2013werereachedwiththeIRS.Therewerenouncertaintaxpositionsrelatedtothe2012taxyear,asofDecember31,2014,sothissettlementdidnotaffecttheamountofrecordedunrecognizedtaxbenefitsduring2015.Thesettlementrelatedtothe2013taxyearresolvedtheuncertaintaxpositionassociatedwiththe finaltaxbasisofNewAERandtherelatedtaxbenefitresultingfromthedivestedmerchantgenerationbusiness.The settlementresultedinareductionofAmeren'sunrecognizedtaxbenefitsof$53millionandanincreasetonetincomefrom discontinuedoperations.SeeNote16-DivestitureTransactionsandDiscontinuedOperationsforadditionalinformation.

125 In2014,finalsettlementsfortaxyears2007through2011werereachedwiththeIRS.Thesesettlements,whichresolvedtheuncertaintaxpositionsassociatedwiththetimingofresearchtaxdeductionsfortheseyears,resultedinadecreaseinAmeren'sandAmerenMissouri'sunrecognizedtaxbenefitsof$20million,and$13million,respectively.Inaddition,the settlementfortaxyears2007through2011providedcertaintyforthepreviouslyuncertaintaxpositionsassociatedwiththe timingofresearchtaxdeductionsfortheremainingopentaxyearsof2012,2013,and2014.Thecertaintyprovidedfromthe settlementresultedinan$18milliondecreaseinbothAmeren'sandAmerenMissouri'sunrecognizedtaxbenefits.The settlementalsoresultedina$2millionincreasetoAmeren'sstateunrecognizedtaxbenefits.Thenetreductionin unrecognizedtaxbenefitsin2014didnotmateriallyaffectincometaxexpensefortheAmerenCompanies.In2013,unrecognizedtaxbenefitsrelatedtothedeductibilityofexpenditurestomaintain,replace,orimprovesteamorelectricpowergenerationproperty,alongwithcasualtylossdeductionsforstormdamage,werereducedby$103million,

$95million,and$5millionforAmeren,AmerenMissouri,andAmerenIllinois,respectively.Thisreductioninunrecognizedtax benefitsdidnotaffectincometaxexpensefortheAmerenCompanies.However,theliabilityforinterestrelatedtothese unrecognizedtaxbenefitswasreleasedin2013.In2013,Amerenadoptedanaccountingmethodchangeasaresultof guidanceissuedbytheIRS,withrespecttotheamountandtimingofthedeductionstomaintain,replace,orimprove generationproperty.Stateincometaxreturnsaregenerallysubjecttoexaminationforaperiodofthreeyearsafterfiling.Thestateimpactofanyfederalchangesremainssubjecttoexaminationbyvariousstatesforuptooneyearafterformalnotificationtothestates.TheAmerenCompaniescurrentlydonothavematerialstateincometaxissuesunderexamination,administrativeappeals,or

litigation.AmerenMissourihasanuncertaintaxpositiontracker.UnderMissouri'sregulatoryframework,uncertaintaxpositionsdonotreduceAmerenMissouri'selectricratebase.Whenanuncertainincometaxpositionliabilityisresolved,theMoPSC requires,throughtheuncertaintaxpositiontracker,thecreationofaregulatoryassetorregulatoryliabilitytoreflectthetime value,usingtheweighted-averagecostofcapitalincludedineachoftheelectricrateordersineffectbeforethetaxposition wasresolved,ofthedifferencebetweentheuncertaintaxpositionliabilitythatwasexcludedfromratebaseandthefinaltax liability.Theresultingregulatoryassetorliabilitywillaffectearningsintheyearitiscreatedandthenwillbeamortizedover threeyears,beginningontheeffectivedateofnewratesestablishedinthenextelectricratecase.NOTE14-RELATEDPARTYTRANSACTIONSInthenormalcourseofbusiness,theAmerenCompanieshaveengagedin,andmayinthefutureengagein,affiliatetransactions.Thesetransactionsprimarily consistofnaturalgasandpowerpurchasesandsales, servicesreceivedorrendered,andborrowingsand lendings.Transactionsbetweenaffiliatesarereportedas intercompanytransactionsontheirfinancialstatements,but areeliminatedinconsolidationforAmeren'sfinancial statements.Belowarethematerialrelatedparty

agreements.ElectricPowerSupplyAgreementsAmerenIllinoismustacquirecapacityandenergysufficienttomeetitsobligationstocustomers.AmerenIllinoisusesperiodicRFPprocessesthatareadministered bytheIPAandapprovedbytheICC,tocontractcapacity andenergyonbehalfofitscustomers.AmerenMissouri participatesintheRFPprocessandhasbeenawinning supplierforcertainperiods.CapacitySupplyAgreementsIn2010,AmerenMissouricontractedtosupplyaportionofAmerenIllinois'capacityrequirementsforlessthan$1millionfortheperiodfromJune1,2010,through May31,2013.Inaprocurementeventin2012,Ameren MissouricontractedtosupplyaportionofAmerenIllinois' capacityrequirementsfor$1millionand$3millionforthe 12monthsendingMay31,2014,and2015,respectively.In aprocurementeventin2015,AmerenMissouricontractedtosupplyaportionofAmerenIllinois'capacity requirementsfor$15millionforthe12monthsending May31,2017.EnergySwapsandEnergyProductsAsaresultofanIPAprocurementeventin2011,AmerenMissouriandAmerenIllinoisenteredintoenergyproductagreementsbywhichAmerenMissouriagreedto sellandAmerenIllinoisagreedtopurchaseapproximately 40,800megawatthoursatapproximately$29per megawatthourduringthe12monthsendedMay31,2013, andapproximately40,800megawatthoursatapproximately

$28permegawatthourduringthe12monthsended May31,2014.Theenergyproductagreementsforthe periodendedMay31,2013,wereforoff-peakhoursonly.AsaresultofanIPAprocurementeventin2014,AmerenMissouriandAmerenIllinoisenteredintoenergy productagreementsbywhichAmerenMissouriagreedto sellandAmerenIllinoisagreedtopurchaseapproximately 168,400megawatthoursatapproximately$51per megawatthourduringtheperiodofJanuary1,2015, throughFebruary28,2017.AsaresultofanIPAprocurementeventinApril2015,AmerenMissouriandAmerenIllinoisenteredintoenergy productagreementsbywhichAmerenMissouriagreedto sellandAmerenIllinoisagreedtopurchase667,000 megawatthoursatanaveragepriceof$36per megawatthourduringtheperiodofJune1,2015,through June30,2017.AlsoinSeptember2015,AmerenMissouri 126 andAmerenIllinoisenteredintoenergyproductagreementsbywhichAmerenMissouriagreedtosellandAmeren Illinoisagreedtopurchase339,000megawatthoursatan averagepriceof$38permegawatthourduringtheperiodof November1,2015,throughMay31,2018.InterconnectionandTransmissionAgreementsAmerenMissouriandAmerenIllinoisarepartiestoaninterconnectionagreementfortheuseoftheirrespectivetransmissionlinesandotherfacilitiesforthedistributionof power.Theseagreementshavenocontractualexpiration date,butmaybeterminatedbyeitherpartywiththreeyears'

notice.SupportServicesAgreementsAmerenServicesprovidessupportservicestoitsaffiliates.Thecostsofsupportservices,includingwages,employeebenefits,professionalservices,andother expenses,arebasedon,orareanallocationof,actualcosts incurred.Thesupportservicesagreementcanbe terminatedatanytimebythemutualagreementofAmeren Servicesandthataffiliateorbyeitherpartywith60days' noticebeforetheendofacalendaryear.Inaddition,AmerenMissouriandAmerenIllinoisprovideaffiliates,primarilyAmerenServices,withaccessto theirfacilitiesforadministrativepurposes.Thecostsofthe rentandfacilityservicesarebasedon,orareanallocation of,actualcostsincurred.Separately,AmerenMissouriandAmerenIllinoisprovidestorm-relatedandmiscellaneoussupportservices toeachotheronanas-neededbasis.TransmissionServicesAmerenIllinoistakestransmissionservicefromMISOfortheretailloaditservesintheAMILpricingzone.ATXIis oneofthetransmissionownersintheAMILpricingzone.

Accordingly,ATXIreceivestransmissionpaymentsfrom AmerenIllinoisthroughtheMISObillingprocess.MoneyPoolSeeNote4-Short-termDebtandLiquidityandNote5-Long-termDebtandEquityFinancingsforadiscussionofaffiliateborrowingarrangements.CollateralPostingsUnderthetermsoftheIllinoispowerprocurementagreementsenteredintothroughRFPprocessesadministeredbytheIPA,suppliersmustpostcollateral undercertainmarketconditionstoprotectAmerenIllinois intheeventofnonperformance.Thecollateralpostingsare unilateral,whichmeansthatonlythesupplierscanbe requiredtopostcollateral.Therefore,AmerenMissouri,asa winningsupplierintheRFPprocess,mayberequiredto postcollateral.AsofDecember31,2015and2014,there werenocollateralpostingsrequiredofAmerenMissouri relatedtotheIllinoispowerprocurementagreements.TaxAllocationAgreementSeeNote1-SummaryofSignificantAccountingPoliciesforadiscussionofthetaxallocationagreement.AtDecember31,2015and2014,AmerenMissouriaccrued capitalcontributionsfromAmeren(parent)of$38million and$9million,respectively,pursuanttothetaxallocation

agreement.ThefollowingtablepresentstheimpactonAmerenMissouriandAmerenIllinoisofrelatedpartytransactionsfortheyearsendedDecember31,2015,2014,and2013.Itisbasedprimarilyontheagreementsdiscussedaboveandthemoney poolarrangementsdiscussedinNote4-Short-termDebtandLiquidity.

AgreementIncomeStatementLineItem Ameren Missouri Ameren IllinoisAmerenMissouripowersupplyagreementsOperatingRevenues2015$15$(a)withAmerenIllinois20145(a)20133(a)AmerenMissouriandAmerenIllinoisOperatingRevenues2015254rentandfacilityservices2014212 2013211AmerenMissouriandAmerenIllinoisOperatingRevenues20152(b)miscellaneoussupportservices20141(b) 201313TotalOperatingRevenues2015$42$4 2014272 2013254 127 AgreementIncomeStatementLineItem Ameren Missouri Ameren IllinoisAmerenIllinoispowersupplyPurchasedPower2015$(a)$15agreementswithAmerenMissouri2014(a)52013(a)3AmerenIllinoistransmissionPurchasedPower2015(a)2serviceswithATXI2014(a)2 2013(a)2TotalPurchasedPower2015$(a)$17 2014(a)7 2013(a)5AmerenServicessupportservicesOtherOperationsand2015$131$119 agreement Maintenance2014124109 201311693TotalOtherOperationsand2015$131$119MaintenanceExpenses2014124109 201311693Moneypoolborrowings(advances)Interest(Charges)2015$(b)$(b)

Income2014(b)(b) 2013(b)(b)(a)Notapplicable.

(b)Amountlessthan$1million.NOTE15-COMMITMENTSANDCONTINGENCIESWeareinvolvedinlegal,tax,andregulatoryproceedingsbeforevariouscourts,regulatorycommissions,authorities,andgovernmentalagencieswithrespecttomattersthatariseintheordinarycourseofbusiness,someofwhichinvolvesubstantialamountsofmoney.Webelievethatthefinaldispositionoftheseproceedings,exceptasotherwisedisclosedinthesenotesto ourfinancialstatements,willnothaveamaterialadverseeffectonourresultsofoperations,financialposition,orliquidity.SeealsoNote1-SummaryofSignificantAccountingPolicies,Note2-RateandRegulatoryMatters,Note10-CallawayEnergyCenter,andNote14-RelatedPartyTransactionsinthisreport.CallawayEnergyCenterThefollowingtablepresentsinsurancecoverageatAmerenMissouri'sCallawayenergycenteratDecember31,2015.ThepropertycoverageandthenuclearliabilitycoveragemustberenewedonApril1andJanuary1,respectively,ofeachyear.TypeandSourceofCoverageMaximumCoveragesMaximumAssessmentsPublicliabilityandnuclearworkerliability:AmericanNuclearInsurers

..............................$375$-Poolparticipation

.....................................

13,114 (a)127 (b)$13,489 (c)$127Propertydamage:NuclearElectricInsuranceLimited........................$

2,750 (d)$27 (e)EuropeanMutualAssociationforNuclearInsurance...........500 (f)-$3,250$27Replacementpower:NuclearElectricInsuranceLimited........................$490 (g)$10 (e)(a)Providedthroughmandatoryparticipationinanindustrywideretrospectivepremiumassessmentprogram.(b)RetrospectivepremiumunderthePrice-AndersonAct.Thisissubjecttoretrospectiveassessmentwithrespecttoacoveredlossinexcessof$375millionintheeventofanincidentatanylicensedUnitedStatescommercialreactor,payableat$19millionperyear.(c)LimitofliabilityforeachincidentunderthePrice-AndersonliabilityprovisionsoftheAtomicEnergyActof1954,asamended.Acompanycouldbeassessedupto$127millionperincidentforeachlicensedreactoritoperates,withamaximumof$19millionperincidenttobepaidina calendaryearforeachreactor.Thislimitissubjecttochangetoaccountfortheeffectsofinflationandchangesinthenumberoflicensed

reactors.(d)NEILprovides$2.25billioninpropertydamage,decontamination,andprematuredecommissioninginsuranceforbothradiationandnonradiationevents.Anadditional$500millionisprovidedforradiationeventsonlyforatotalof$2.75billion.(e)AllNEIL-insuredplantscouldbesubjecttoassessmentsshouldlossesexceedtheaccumulatedfundsfromNEIL.

(f)EuropeanMutualAssociationforNuclearInsuranceprovides$500millioninexcessofthe$2.75billionand$2.25billionpropertycoverageforradiationandnonradiationevents,respectively,providedbyNEIL.

128 (g)Providesreplacementpowercostinsuranceintheeventofaprolongedaccidentaloutage.Weeklyindemnityisupto$4.5millionfor52weeks,whichcommencesafterthefirsttwelveweeksofanoutage,plusupto$3.6millionperweekforaminimumof71weeksthereafter,foratotalnotexceedingthepolicylimitof$490million.Nonradiationeventsaresub-limitedto$328million.ThePrice-AndersonActisafederallawthatlimitstheliabilityforclaimsfromanincidentinvolvinganylicensedUnitedStatescommercialnuclearenergycenter.Thelimitisbasedonthenumberoflicensedreactors.ThelimitofliabilityandthemaximumpotentialannualpaymentsareadjustedatleasteveryfiveyearsforinflationtoreflectchangesintheConsumer PriceIndex.Themostrecentfive-yearinflationaryadjustmentbecameeffectiveinSeptember2013.Ownersofanuclear reactorcoverthisexposurethroughacombinationofprivateinsuranceandmandatoryparticipationinafinancialprotection pool,asestablishedbythePrice-AndersonAct.LossesresultingfromterroristattacksonnuclearfacilitiesarecoveredunderNEIL'spolicies,subjecttoanindustrywideaggregatepolicycoveragelimitof$3.24billionwithina12-monthperiod,or$1.83billionforeventsnotinvolvingradiation

contamination.IflossesfromanuclearincidentattheCallawayenergycenterexceedthelimitsof,orarenotcoveredby,insuranceorifcoverageisunavailable,AmerenMissouriisatriskforanyuninsuredlosses.Ifaseriousnuclearincidentweretooccur,it couldhaveamaterialadverseeffectonAmeren'sandAmerenMissouri'sresultsofoperations,financialposition,andliquidity.

LeasesWeleasevariousfacilities,officeequipment,plantequipment,andrailcarsundercapitalandoperatingleases.ThefollowingtablepresentsourleaseobligationsatDecember31,2015:20162017201820192020After5YearsTotal Ameren: (a)Minimumcapitalleasepayments (b)..........................$33$33$32$32$32$329$491Lessamountrepresentinginterest..........................272726252573203Presentvalueofminimumcapitalleasepayments..............$6$6$6$7$7$256$288Operatingleases (c).......................................14131212113092Totalleaseobligations...................................$20$19$18$19$18$286$380AmerenMissouri:Minimumcapitalleasepayments (b)..........................$33$33$32$32$32$329$491Lessamountrepresentinginterest..........................272726252573203Presentvalueofminimumcapitalleasepayments..............$6$6$6$7$7$256$288Operatingleases (c).......................................12111111102984Totalleaseobligations...................................$18$17$17$18$17$285$372AmerenIllinois:

Operatingleases (c).......................................$1$1$1$1$1$1$6(a)IncludesamountsforAmerenregistrantandnonregistrantsubsidiariesandintercompanyeliminations.

(b)SeePropertiesunderPartI,Item2,andNote3-PropertyandPlant,Net,ofthisreportforadditionalinformation.

(c)Amountsrelatedtocertainland-relatedleaseshaveindefinitepaymentperiods.Theannualobligationsof$3million,$2million,and$1millionforAmeren,AmerenMissouri,andAmerenIllinoisfortheseitemsareincludedinthe2016through2020columns,respectively.ThefollowingtablepresentstotalrentalexpenseincludedinoperatingexpensesfortheyearsendedDecember31,2015,2014,and2013:201520142013 Ameren (a).........................................................................$36$37$32AmerenMissouri

...................................................................

343229AmerenIllinois

.....................................................................

282521(a)IncludesamountsforAmerenregistrantandnonregistrantsubsidiariesandintercompanyeliminations.

129 OtherObligationsTosupplyaportionofthefuelrequirementsofourenergycenters,wehaveenteredintovariouslong-termcommitmentsfortheprocurementofcoal,naturalgas,nuclearfuel,andmethanegas.Wealsohaveenteredintovariouslong-termcommitmentsforpurchasedpowerandnaturalgasfordistribution.Thetablebelowpresentsourestimatedfuel,purchased power,andothercommitmentsforfuelatDecember31,2015.Ameren'sandAmerenMissouri'spurchasedpower commitmentsincludea102-megawattpowerpurchaseagreementwithawindfarmoperator,whichexpiresin2024.Ameren's andAmerenIllinois'purchasedpowercommitmentsincludetheAmerenIllinoispowerpurchaseagreementsenteredintoas partoftheIPA-administeredpowerprocurementprocess.IncludedintheOthercolumnareminimumpurchasecommitments undercontractsforequipment,designandconstruction,andmeterreadingservicesatDecember31,2015.

Coal Natural Gas (a)Nuclear Fuel Purchased Power (b)MethaneGasOtherTotal Ameren: (c)2016.....................$664$249$51$241$3$115$

1,323 2017.....................68519046147473 1,145 2018.....................2041276872555531 2019.....................110892458556342 2020.....................-435158657215 Thereafter.................-6010853971350 1,128 Total.....................$1,663$758$348$1,115$94$706$4,684AmerenMissouri:

2016.....................$664$46$51$23$3$46$833 2017.....................685364623432826 2018.....................204246823528352 2019.....................110142423529205 2020.....................-105123630120 Thereafter.................-231088471183469 Total.....................$1,663$153$348$199$94$348$2,805AmerenIllinois:

2016.....................$-$203$-$218$-$31$452 2017.....................-154-124-25303 2018.....................-103-49-24176 2019.....................-75-35-27137 2020.....................-33-35-2795 Thereafter.................-37-455-167659 Total.....................$-$605$-$916$-$301$

1,822(a)Includesamountsforgenerationandfordistribution.

(b)ThepurchasedpoweramountsforAmerenandAmerenIllinoisincludeagreementsthrough2032forrenewableenergycreditswithvariousrenewableenergysuppliers.TheagreementscontainaprovisionthatallowsAmerenIllinoistoreducethequantitypurchasedintheeventthat AmerenIllinoiswouldnotbeabletorecoverthecostsassociatedwiththerenewableenergycredits.(c)IncludesamountsforAmerenregistrantandnonregistrantsubsidiaries.EnvironmentalMattersWearesubjecttovariousenvironmentallawsandregulationsenforcedbyfederal,state,andlocalauthorities.Fromthebeginningphasesofsitinganddevelopmenttothe operationofelectricgeneration,transmission,and distributionfacilitiesandnaturalgasstorage,transmission, anddistributionfacilities,ouractivitiesinvolvecompliance withdiverseenvironmentallawsandregulations.These lawsandregulationsaddressemissions,dischargesto water,waterusage,impactstoair,land,andwater,and chemicalandwastehandling.Complexandlengthy processesarerequiredtoobtainandrenewapprovals, permits,andlicensesfornew,existingormodifiedfacilities.

Additionally,theuseandhandlingofvariouschemicalsor hazardousmaterialsrequirereleasepreventionplansand emergencyresponseprocedures.TheEPAhaspromulgatedseveralenvironmentalregulationsthatwillhaveasignificantimpactontheelectric utilityindustry.Overtime,compliancewiththeseregulations couldbecostlyforcertaincompanies,includingAmeren Missouri,thatoperatecoal-firedpowerplants.Significant newrulesincludetheregulationofCO 2emissionsfromexistingpowerplantsthroughtheCleanPowerPlanandfrom newpowerplantsthroughtherevisedNSPS;theCSAPR, whichrequiresfurtherreductionsofSO 2emissionsandNO xemissionsfrompowerplants;aregulationgoverning managementandstorageofCCR;theMATS,whichrequire reductionofemissionsofmercury,toxicmetals,andacid gasesfrompowerplants;revisedNSPSforparticulate matter,SO 2,andNO xemissionsfromnewsources;neweffluentstandardsapplicabletowastewaterdischargesfrom powerplantsandnewregulationsundertheCleanWaterAct thatcouldrequiresignificantcapitalexpenditures,suchas 130 modificationstowaterintakestructuresornewcoolingtowersatAmerenMissouri'senergycenters.TheEPAalso periodicallyreviewsandrevisesnationalambientairquality standards,includingthosestandardsassociatedwith emissionsfrompowerplants,suchasparticulatematter, ozone,SO 2andNO x.Certainofthesenewregulationsarebeingorarelikelytobechallengedthroughlitigation,sotheir ultimateimplementation,aswellasthetimingofanysuch implementation,isuncertain.Althoughmanydetailsoffuture regulationsareunknown,individuallyorthecombinedeffects ofnewenvironmentalregulationscouldresultinsignificant capitalexpendituresandincreasedoperatingcostsfor AmerenandAmerenMissouri.Compliancewithallofthese environmentallawsandregulationscouldbeprohibitively expensive,resultintheclosureoralterationoftheoperation ofsomeofAmerenMissouri'senergycenters,orrequire capitalinvestment.AmerenandAmerenMissouriexpectthat thesecostswouldberecoverablethroughrates,subjectto MoPSCprudencereview,butthenatureandtimingofcosts couldresultinregulatorylag.AmerenMissouri'scurrentplanforcompliancewithexistingenvironmentalregulationsforairemissions includesburningultra-low-sulfurcoalandinstallingnewor optimizingexistingpollutioncontrolequipment.Ameren andAmerenMissouriestimatethattheywillneedtomake capitalexpendituresof$600millionto$700millioninthe aggregatefrom2016through2020inordertocomplywith existingenvironmentalregulations.AmerenMissourimay berequiredtoinstalladditionalairemissionscontrols withinthenextsixto10years.Thisestimateincludesour capitalexpendituresrequiredfortheCCRregulationsthat werepublishedin2015,theruleapplicabletocoolingwater intakestructuresatexistingpowerplantsundertheClean WaterAct,andtheeffluentlimitationguidelinesapplicable tosteamelectricgeneratingunitsundertheCleanWater Act,allofwhicharediscussedbelow.Theseestimatesdo notincludetheimpactsoftheCleanPowerPlandiscussed below.Considerableuncertaintyremainsintheseestimates.

Theactualamountofcapitalexpendituresrequiredto complywithexistingenvironmentalregulationsmayvary substantiallyfromtheaboveestimateduetouncertaintyas totheprecisecompliancestrategiesthatwillbeusedand theirultimatecost,amongotherthings.Thefollowingsectionsdescribethemoresignificantnewenvironmentallawsandrulesandenvironmental enforcementandremediationmattersthataffectorcould affectouroperations.CleanAirActFederalandstatelawsrequiresignificantreductionsin SO 2andNO xthrougheitheremissionsourcereductionsortheuseandretirementofemissionallowances.TheCSAPRbecameeffectivein2015.Therewillbefurtheremission reductionrequirementsin2017andpotentiallymorein subsequentyears.ToachievecompliancewithCSAPR, AmerenMissouriburnsultra-low-sulfurcoalandoperates twoscrubbersatitsSiouxenergycenter.AmerenMissouri doesnotexpecttomakeadditionalcapitalinvestmentstocomplywiththecurrentCSAPRrequirements.However, AmerenMissouriexpectstoincuradditionalcostsasit lowersitsemissionsatoneormoreofitsenergycentersto complywiththeCSAPRinfutureyears.Thesehighercosts areexpectedtobecollectedfromcustomersthroughthe FACorhigherbaserates.InDecember2011,theEPAissuedtheMATSundertheCleanAirAct,whichrequiresreductionsinemissionsof mercuryandotherhazardousairpollutants,suchasacid gases,tracemetals,andhydrogenchloride.TheMATSdo notrequireaspecificcontroltechnologytoachievethe emissionreductions.TheMATSapplytoeachunitatacoal-firedpowerplant.However,incertaincases,compliance canbeachievedbyaveragingemissionsfromsimilarunits atthesamepowerplant.CompliancewasrequiredbyApril 2015or,withacase-by-caseextension,byApril2016.All ofAmerenMissouri'scoal-firedpowerplantswillbein compliancebeforetherequiredduedates.Aspartof AmerenMissouri'scomplianceplan,theMeramecenergy centerwillburnnaturalgasattwoofitsunitsbeginningin April2016,therebyexcludingsuchunitsfromtheMATS.In addition,AmerenMissouriisincurringadditionalcoststo complywiththeMATS.Thesehighercostsarebeing collectedfromcustomersthroughtheFACorhigherbase

rates.CO 2EmissionsStandardsTheCleanPowerPlan,whichsetsforthCO 2 emissionsstandardsapplicabletoexistingpowerplants,wasissuedbytheEPAbutstayedbytheUnitedStatesSupremeCourt pendingtheoutcomeofvariousappeals,asdiscussed

below.IftheCleanPowerPlanisultimatelyupheldasissued,AmerenMissouriexpectstoincurincreasedfueland operatingcosts,andmakeneworacceleratedcapital expenditures,inadditiontothecostsofmaking modificationstoexistingoperationsinordertoachieve compliance.TheCleanPowerPlanrequiredMissouriand IllinoistoreduceCO 2emissionsfrompowerplantswithintheirstatessignificantlybelow2005levelsby2030.The rulecontainsinterimcomplianceperiodscommencingin 2022thatrequireeachstatetodemonstrateprogressin achievingitsCO 2reductiontarget.AmerenisevaluatingtheCleanPowerPlan'spotentialimpactstoitsoperations, includingthoserelatedtoelectricsystemreliability,andto itslevelofinvestmentincustomerenergyefficiency programs,renewableenergy,andotherformsofgeneration investment.Significantuncertaintyexistsregardingthe impactoftheCleanPowerPlan,asitsimplementationwill dependuponplanstobedevelopedbythestates.

Numerouslegalchallengesarepending,whichcouldresult intherulebeingdeclaredinvalidorthenatureandtimingof

CO 2emissionsreductionsbeingrevised.InFebruary2016,theUnitedStatesSupremeCourtstayedtheCleanPower Planandallimplementationrequirementsuntilsuchtimeas legalappealsareconcluded.TheDistrictofColumbiaCircuit CourtofAppealshasscheduledhearingsforJune2016on thelegalityoftherule.AdecisionbytheDistrictof 131 ColumbiaCircuitCourtofAppealsisexpectedtobeissuedlaterthisyearandadditionalappealsbeforetheUnited StatesSupremeCourtarelikely.Appealsarenotexpected toconcludepriorto2018.Wecannotpredicttheoutcome ofsuchlegalchallengesortheirimpactonourresultsof operations,financialposition,orliquidity.Iftheruleis ultimatelyupheldandimplementedinsubstantiallysimilar formtotherulewhenissued,compliancemeasurescould resultintheclosureoralterationoftheoperationofsome ofAmerenMissouri'scoalandnatural-gas-firedenergy centers,whichcouldresultinincreasedoperatingcosts.

AmerenMissouriexpectssubstantiallyallofthese increasedcoststoberecoverable,subjecttoMoPSC prudencereview,throughhigherratestocustomers,which couldbesignificant.Also,inAugust2015,theEPAissuedfinalregulationsthatsetCO 2emissionsstandardsfornewpowerplants.Thesenewstandardsestablishseparateemissionslimitsfor newnatural-gas-firedcombinedcycleplantsandnewcoal-firedplants.FederalandstatelegislationorregulationsthatmandatelimitsontheemissionofCO 2mayresultinsignificantincreasesincapitalexpendituresandoperating costs,whichcouldleadtoincreasedliquidityneedsand higherfinancingcosts.Mandatorylimitsontheemissionof

CO 2couldincreasecostsforAmerenMissouri'scustomersorhaveamaterialadverseeffectonAmeren'sandAmeren Missouri'sresultsofoperations,financialposition,and liquidityifregulatorsdelayordenyrecoveryinratesof thesecompliancecosts.ThecostofAmerenIllinois' purchasedpowerandgaspurchasedforresalecould increase.However,AmerenIllinoisexpectsthesecosts wouldberecoveredfromcustomerswithnomaterial adverseeffectonitsresultsofoperations,financialposition, orliquidity.Ameren'sandAmerenMissouri'searnings mightbenefitfromincreasedinvestmenttocomplywith

CO 2emissionlimitationstotheextentthattheinvestmentsarereflectedandrecoveredonatimelybasisinrates chargedtocustomers.NSRandCleanAirLitigationInJanuary2011,theDepartmentofJustice,onbehalfoftheEPA,filedacomplaintagainstAmerenMissouriintheUnitedStatesDistrictCourtfortheEasternDistrictof Missouri.TheEPA'scomplaint,asamendedinOctober 2013,allegesthatinperformingprojectsatitsRushIsland coal-firedenergycenterin2007and2010,Ameren MissouriviolatedprovisionsoftheCleanAirActand Missourilaw.AmerenMissourianticipatesthatatrialofthis casecouldoccurasearlyas2016.AmerenMissouri believesitsdefensesaremeritoriousandisdefendingitself vigorously.However,therecanbenoassurancesthatitwill besuccessfulinitsefforts.Theultimateresolutionofthismattercouldhaveamaterialadverseeffectontheresultsofoperations, financialposition,andliquidityofAmerenandAmeren Missouri.Aresolutionofthismattercouldresultinincreasedcapitalexpendituresfortheinstallationof pollutioncontrolequipmentandincreasedoperationsand maintenanceexpenses.Weareunabletopredictthe ultimateresolutionofthesemattersorthecoststhatmight beincurred.CleanWaterActInAugust2014,theEPAissueditsfinalruleapplicabletocoolingwaterintakestructuresatexistingpowerplants.Therulerequiresacase-by-caseevaluationandplanfor reducingaquaticorganismsimpingedonthefacility'sintake screensorentrainedthroughtheplant'scoolingwater system.AllofAmerenMissouri'scoal-firedandnuclear energycentersaresubjecttothisrule.EachofAmeren Missouri'saffectedenergycenterswillbecomesubjectto therevisedlimitationswhenitrenewsitswaterdischarge permit.Thesepermitsarescheduledtoberenewed between2018and2023.Therulecouldhaveanadverse effectonAmeren'sandAmerenMissouri'sresultsof operations,financialposition,andliquidityifits implementationrequirestheinstallationofcoolingtowers orextensivemodificationstothecoolingwatersystemsat ourenergycentersandifthoseinvestmentsarenot recoveredonatimelybasisinelectricrateschargedto AmerenMissouri'scustomers.InSeptember2015,theEPAissueditsfinalruleundertheCleanWaterActtorevisetheeffluentlimitation guidelinesapplicabletosteamelectricgeneratingunits.

Effluentlimitationguidelinesarenationalstandardsfor waterdischargesthatarebasedontheeffectivenessof availablecontroltechnology.TheEPA'sruleprohibits effluentdischargesofcertain,butnotall,wastestreams andimposesmorestringentlimitationsoncertain componentsinwaterdischargesfrompowerplants.Allof AmerenMissouri'scoal-firedenergycentersaresubjectto thisruleanditsimplementationwillbeconsistentwiththe waterdischargepermitprocessdescribedabovebeginning asearlyas2018.AmerenMissouriisevaluatingthefinal rule,whichbecameeffectiveinJanuary2016,andthe possibleeffectsonitsoperations.AshManagementIn2015,theEPAissuedregulationsregardingthemanagementanddisposalofCCR,thatwillaffectfutureCCRdisposalandhandlingcostsatAmerenMissouri's energycenters.Theregulationsallowforthemanagement ofCCRasasolidwaste,aswellasforitscontinued beneficialuses,suchasrecycling,whichcouldreducethe amounttobedisposed.Theregulationsalsoestablish criteriaregardingthestructuralintegrity,location,and operationofCCRimpoundmentsandlandfills.Theyrequire groundwatermonitoringandclosureofimpoundmentsif thegroundwaterstandardsarenotachieved.During2015, AmerenandAmerenMissourirecordedanincreasetotheir AROsassociatedwithCCRstoragefacilitiesandaccelerated theclosureofcertainCCRstoragefacilitiesatitsenergy centersasaresultofthenewregulations.AmerenMissouri planstoclosetheseCCRstoragefacilitiesbetween2018 132 and2023.SeeNote1-SummaryofSignificantAccountingPoliciesinthisreportforadditionalinformation.Ameren Missouri'scapitalexpenditureplanincludesthecostof constructinglandfillsaspartofitsenvironmental complianceplan.Thenewregulationsdonotapplytoashpondsatplantsnolongerinoperation,suchasAmeren'sMeredosia andHutsonvilleenergycenters.

RemediationTheAmerenCompaniesareinvolvedinanumberofremediationactionstocleanupsitesaffectedbyhazardoussubstances,asrequiredbyfederalandstatelaw.Suchlaws requirethatresponsiblepartiesfundremediationactions regardlessoftheirdegreeoffault,thelegalityoforiginal disposal,ortheownershipofadisposalsite.Ameren MissouriandAmerenIllinoishaveeachbeenidentifiedby federalorstategovernmentsasapotentiallyresponsible partyatseveralcontaminatedsites.AsofDecember31,2015,AmerenIllinoisownedorwasotherwiseresponsiblefor44formerMGPsitesin Illinois,whichareinvariousstagesofinvestigation, evaluation,remediation,andclosure.AmerenIllinois estimatesitcouldsubstantiallyconcluderemediationefforts by2025.TheICCallowsAmerenIllinoistorecover remediationandlitigationcostsassociatedwithitsformer MGPsitesfromitselectricandnaturalgasutilitycustomers throughenvironmentaladjustmentrateriders.Costsare subjecttoannualprudencereviewbytheICC.Asof December31,2015,AmerenIllinoisestimatedthe obligationrelatedtotheseformerMGPsitesat$232million to$313million.AmerenandAmerenIllinoisrecordeda liabilityof$232milliontorepresenttheirestimated minimumobligationforthesesites,asnootheramount withintherangewasabetterestimate.ThescopeandextenttowhichtheseformerMGPsitesareremediatedmayincreaseasremediationefforts continue.Considerableuncertaintyremainsinthese estimates,asmanyfactorscaninfluencetheultimateactual costs,includingsite-specificunanticipatedunderground structures,thedegreetowhichgroundwateris encountered,regulatorychanges,localordinances,andsite accessibility.Theactualcostsmayvarysubstantiallyfrom theseestimates.AmerenIllinoisformerlyusedanoff-sitelandfill,whichAmerenIllinoisdidnotown,inconnectionwiththe operationofapreviouslyownedenergycenter.Ameren Illinoiscouldberequiredtoperformcertainmaintenance activitiesatthatlandfill,whichisnowclosed.Asof December31,2015,AmerenIllinoisestimatedthe obligationrelatedtothissiteat$0.5millionto$6million.

AmerenIllinoisrecordedaliabilityof$0.5millionto representitsestimatedminimumobligationforthissite,as nootheramountwithintherangewasabetterestimate.

AmerenIllinoisisalsoresponsibleforthecleanupofsomeundergroundstoragetanksandawatertreatmentplantin Illinois.AsofDecember31,2015,AmerenIllinoisrecorded aliabilityof$0.7milliontorepresentitsbestestimateofthe obligationforthesesites.In2008,theEPAissuedanadministrativeordertoAmerenMissouripertainingtoaformercoaltardistilleryin St.Louis,Missouri,operatedbyKoppersCompanyorits predecessorandsuccessorcompanies.WhileAmeren Missouriisthecurrentownerofthesite,itdidnotconduct anyofthemanufacturingoperationsinvolvingcoaltarorits byproducts.AmerenMissouri,alongwithtwoother potentiallyresponsibleparties,havecompletedsite investigationactivitiesandhavesubmittedtheirfindingsto theEPA.AsofDecember31,2015,AmerenMissouri estimateditsobligationat$2millionto$5million.Ameren Missourirecordedaliabilityof$2milliontorepresentits estimatedminimumobligation,asnootheramountwithin therangewasabetterestimate.AmerenMissourialsoparticipatedintheinvestigationofseveralsiteslocatedinSauget,Illinois.In2000,theEPA notifiedAmerenMissouriandnumerousothercompanies, includingSolutia,Inc.,thatformerlandfillsandlagoonsat thosesitesmaycontainsoilandgroundwater contamination.ThesesitesareknownasSaugetArea2.

Fromabout1926until1976,AmerenMissourioperatedan energycenteradjacenttoSaugetArea2.AmerenMissouri currentlyownsaparcelofpropertyatSaugetArea2that wasonceusedasalandfill.InDecember2013,theEPAissueditsrecordofdecisionforSaugetArea2approvingtheinvestigationand theremediationalternativesrecommendedbythe potentiallyresponsibleparties.Furthernegotiationamong thepotentiallyresponsiblepartieswilldeterminehowto fundtheimplementationoftheEPA-approvedcleanup remedies.AsofDecember31,2015,AmerenMissouri estimateditsobligationrelatedtoSaugetArea2at

$1millionto$2.5million.AmerenMissourirecordeda liabilityof$1milliontorepresentitsestimatedminimum obligation,asnootheramountwithintherangewasa betterestimate.InDecember2012,AmerenMissourisignedanadministrativeorderwiththeEPAandagreedtoinvestigate soilandgroundwaterconditionsatanAmerenMissouri-ownedsubstationinSt.Charles,Missouri.Asof December31,2015,AmerenMissouriestimatedand recordeda$0.6millionliabilityrelatedtothesite.Although monitoringwillcontinueforsometime,nosignificant additionalremediationmeasuresareanticipated.Ouroperationsorthoseofourpredecessorcompaniesinvolvetheuseof,disposalof,andinappropriate circumstances,thecleanupofsubstancesregulatedunder environmentallaws.Weareunabletodeterminewhether suchpracticeswillresultinfutureenvironmental commitmentsorwillaffectourresultsofoperations, financialposition,orliquidity.

133 Pumped-storageHydroelectricFacilityBreachInDecember2005,therewasabreachoftheupperreservoiratAmerenMissouri'sTaumSaukpumped-storagehydroelectricenergycenter.Thebreachresultedin significantfloodinginthelocalarea,whichdamagedastate park.AmerenMissourihadliabilityinsurancecoveragefor theTaumSaukincident,subjecttocertainlimitsand

deductibles.AsofDecember31,2015,AmerenMissourihadaninsurancereceivableof$41million.InFebruary2016, AmerenMissouriandaninsurerthatwasprovidingAmeren MissouriwithliabilitycoverageonthedateoftheTaum SaukincidentreachedasettlementthatresultedinAmeren Missourireceiving$42million.Asaresultofthis settlement,thereceivablewasincludedin"Miscellaneous accountsandnotesreceivable"onAmeren'sandAmeren Missouri'sbalancesheetsasofDecember31,2015 whereaspreviouslythisreceivablewasincludedin"Other assets"ontheirrespectivebalancesheetsasof December31,2014.Asbestos-relatedLitigationAmeren,AmerenMissouri,andAmerenIllinoishavebeennamed,alongwithnumerousotherparties,inanumberoflawsuitsfiledbyplaintiffsclaimingvarying degreesofinjuryfromasbestosexposureatourpresentor formerenergycenters.MosthavebeenfiledintheCircuit CourtofMadisonCounty,Illinois.Thetotalnumberof defendantsnamedineachcasevaries,with75asthe averagenumberofpartiesasofDecember31,2015.Each lawsuitseeksunspecifieddamagesthat,ifawardedattrial, typicallywouldbesharedamongthevariousdefendants.Thefollowingtablepresentsthependingasbestos-relatedlawsuitsfiledagainstAmerenMissouriandAmeren IllinoisasofDecember31,2015:

Ameren Missouri AmerenIllinoisTotal (a)26 38 48(a)TotaldoesnotequalthesumofthesubsidiaryunitlawsuitsbecausesomeofthelawsuitsnamemultipleAmerenentitiesas defendants.AtDecember31,2015,Ameren,AmerenMissouri,andAmerenIllinoishadliabilitiesof$8million,$3million,and$5million,respectively,recordedtorepresenttheirbest estimatesoftheirobligationsrelatedtoasbestosclaims.AmerenIllinoishasatariffridertorecoverthecostsofIPasbestos-relatedlitigationclaims,subjecttothe followingterms:90%ofthecashexpendituresinexcessof theamountincludedinbaseelectricratesistoberecovered fromatrustfundthatwasestablishedwhenAmeren acquiredIP.AtDecember31,2015,thetrustfundbalance was$22million,includingaccumulatedinterest.Ifcashexpendituresarelessthantheamountinbaserates, AmerenIllinoiswillcontribute90%ofthedifferencetothe trustfund.Oncethetrustfundisdepleted,90%ofallowed cashexpendituresinexcessofbaserateswillberecovered throughchargesassessedtocustomersunderthetariff rider.Theriderwillpermitrecoveryfromelectriccustomers withinIP'shistoricalserviceterritory.AmerenMissouriMunicipalTaxesThecitiesofCreveCoeurandWinchester,Missouri,onbehalfofthemselvesandothermunicipalitiesinAmerenMissouri'sservicearea,filedaclassactionlawsuitin November2011againstAmerenMissouriintheCircuit CourtofSt.LouisCounty,Missouri.Thelawsuitallegesthat AmerenMissourifailedtocollectandpaygrossreceipts taxesorlicensefeesoncertainrevenues.Amerenand AmerenMissourirecordedimmaterialliabilitiesontheir respectivebalancesheetsasofDecember31,2015, representingtheirestimateoftaxesandfeesdueasaresult ofthislawsuit.Theultimateresolutionofanyunpaid municipaltaxorfeescouldhaveamaterialadverseeffect ontheresultsofoperations,financialposition,andliquidity ofAmerenandAmerenMissouri.AmerenMissouribelieves itsdefensesaremeritoriousandisdefendingitself vigorously;however,therecanbenoassurancesthat AmerenMissouriwillbesuccessfulinitsefforts.NOTE16-DIVESTITURETRANSACTIONSANDDISCONTINUEDOPERATIONSOnDecember2,2013,AmerencompletedthedivestitureofNewAERtoIPHinaccordancewiththetransactionagreementbetweenAmerenandIPHdated March14,2013,asamendedbyaletteragreementdated December2,2013.Pursuanttothatagreement,in2015, Amerenpaid$25millionrelatedtoapreviously-recorded liabilityandconcludeditsobligationstoprovidecredit supporttoNewAERwithnoresultingadditionalimpactto itsresultsofoperations.Thetransactionagreementwith IPH,asamended,providesthatiftheElgin,GibsonCity, andGrandTowergas-firedenergycentersaresubsequently soldbyMedinaValleyandifMedinaValleyreceives additionalproceedsfromsuchsale,MedinaValleywillpay Gencoanyproceedsfromsuchsale,netoftaxesandother expenses,inexcessofthe$137.5millionpreviouslypaidto

Genco.OnJanuary31,2014,MedinaValleycompletedthesaleoftheElgin,GibsonCity,andGrandTowergas-fired energycenterstoRocklandCapitalforatotalpurchase priceof$168million.TheagreementwithRocklandCapital requiredaportionofthepurchasepricetobeheldin escrowuntilJanuary31,2016,tofundcertainindemnity obligations,ifany,ofMedinaValley.MedinaValleyreceived theescrowbalancefromRocklandCapitalandexpectsto payGencoitsportionofthatescrowbalanceduringthefirst quarterof2016.

134 DiscontinuedOperationsPresentationAllmattersrelatedtothefinaltaxbasisofNewAERandtherelatedtaxbenefitresultingfromthedivestedmerchantgenerationbusinesshavebeenresolvedwiththecompletionoftheIRSauditfor2013.During2015,basedonthecompletionoftheIRSaudit,Amerenremovedareserveforunrecognizedtaxbenefitsrecordedin2013andrecognizedataxbenefitfrom discontinuedoperations.SeeNote13-IncomeTaxesforadditionalinformationregardingtheAmerenCompanies'uncertain taxpositions.ThefollowingtablepresentsthecomponentsofdiscontinuedoperationsinAmeren'sconsolidatedstatementofincome(loss)fortheyearsendedDecember31,2015,2014,and2013:Yearended201520142013Operatingrevenues

...............................................................

$-$1$1,037Operatingbenefits(expenses)

.......................................................

1(2)(1,207)(a)Operatingincome(loss)

............................................................

1(1)(170)Otherincome(loss)

...............................................................

--(1)Interestcharges

..................................................................

--(39)Income(loss)beforeincometaxes

...................................................

1(1)(210)Incometax(expense)benefit

........................................................

50-(13)Income(loss)fromdiscontinuedoperations,netoftaxes

..................................$51$(1)$(223)(a)Includesa$201millionpretaxlossondisposalrelatingtotheNewAERdivestiture.ThefollowingtablepresentsthecarryingamountsofthecomponentsofassetsandliabilitiesofAmeren'sdiscontinuedoperations,whichconsistprimarilyofAROsandrelateddeferredincometaxassetsassociatedwiththeabandonedMeredosia andHutsonvilleenergycenters,atDecember31,2015and2014:December31,2015December31,2014AssetsofdiscontinuedoperationsAccumulateddeferredincometaxes,net

.............................................$14$15Totalassetsofdiscontinuedoperations

................................................$14$15LiabilitiesofdiscontinuedoperationsAccountspayableandothercurrentobligations

.......................................

$1$1Assetretirementobligations (a).....................................................

28 32Totalliabilitiesofdiscontinuedoperations

..............................................$29$33(a)AmerenisdemolishingtheHutsonvilleenergycenterandexpectstodemolishtheMeredosiaenergycenterbeginningin2016.NOTE17-SEGMENTINFORMATIONAmerenhastworeportablesegments:AmerenMissouriandAmerenIllinois.AmerenMissouriandAmeren Illinoiseachhaveonereportablesegment.TheAmeren MissourisegmentforbothAmerenandAmerenMissouri includesalltheoperationsofAmerenMissouriasdescribed inNote1-SummaryofSignificantAccountingPolicies.

TheAmerenIllinoissegmentforbothAmerenandAmerenIllinoisconsistsofalloftheoperationsofAmerenIllinoisas describedinNote1-SummaryofSignificantAccounting Policies.ThecategorycalledOtherprimarilyincludes Amerenparentcompanyactivities,AmerenServices,and ATXI.TheOthercategoryalsoincludescertaincorporate activitiespreviouslyincludedintheMerchantGeneration segment.SeeNote16-DivestitureTransactionsand DiscontinuedOperationsforadditionalinformation.

135 ThefollowingtablepresentsinformationaboutthereportedrevenuesandspecifieditemsreflectedinAmeren'snetincomeattributabletoAmerencommonshareholdersandcapitalexpendituresfromcontinuingoperationsfortheyearsendedDecember31,2015,2014,and2013,andtotalassetsincontinuingoperationsasofDecember31,2015,2014,and2013:

Ameren Missouri AmerenIllinoisOther IntersegmentEliminationsConsolidated 2015Externalrevenues

..............................................$3,566$2,462$70$-$6,098Intersegmentrevenues

..........................................4342(49)-Depreciationandamortization

....................................4922959-796Interestanddividendincome

.....................................28121-41Interestcharges

...............................................2191315-355Incometaxes

.................................................20912727-363NetincomeattributabletoAmerencommonshareholdersfromcontinuing operations

.................................................35221413-579Capitalexpenditures

............................................622918377 (a)-1,917Totalassets (c).................................................13,8518,9031,139(267)23,626 (b)2014 Externalrevenues..............................................$3,526$2,496$31$-$6,053Intersegmentrevenues..........................................2722(31)-Depreciationandamortization....................................4732639-745Interestanddividendincome.....................................2872-37Interestcharges...............................................21111218-341Incometaxes.................................................2291435-377Netincome(loss)attributabletoAmerencommonshareholdersfromcontinuingoperations........................................390201(4)-587Capitalexpenditures............................................747835203 (a)-1,785Totalassets (c).................................................13,4748,204799(203)22,274 (b)2013 Externalrevenues..............................................$3,516$2,307$15$-$5,838Intersegmentrevenues..........................................2542(31)-Depreciationandamortization....................................4542439-706Interestanddividendincome.....................................2721-30Interestcharges...............................................21014345-398Incometaxes(benefit)..........................................242110(41)-311Netincome(loss)attributabletoAmerencommonshareholdersfromcontinuingoperations........................................395160(43)-512Capitalexpenditures............................................64870130 (a)-1,379Totalassets (c).................................................12,8677,397711(233)20,742 (b)(a)Includestheeliminationofintercompanytransfers.

(b)Excludestotalassetsfromdiscontinuedoperationsof$14million,$15million,and$165millionasofDecember31,2015,2014,and2013, respectively.(c)Reflectstheadoptionofthenewauthoritativeaccountingguidanceforthepresentationofdebtissuancecostsandbalancesheetclassificationofdeferredincometaxes.SeeNote1-SummaryofSignificantAccountingPoliciesforadditionalinformation.

136 SELECTEDQUARTERLYINFORMATION(Unaudited)(Inmillions,exceptpershareamounts)

Ameren 2015 2014Quarterended (a)March31June30September30December31March31June30September30December31Operatingrevenues

.....................$1,556$1,401$1,833$1,308$1,594$1,419$1,670$1,370Operatingincome

.......................256237626140246322561125Netincome............................110151345309815029549NetincomeattributabletoAmerencommonshareholders-continuingoperations

.....$108$98$343$30$97$150$294$46Netincome(loss)attributabletoAmerencommonshareholders-discontinued operations

..........................-52-(1)(1)(1)(1)2NetincomeattributabletoAmerencommon shareholders

........................$108$150$343$29$96$149$293$48Earningspercommonshare-basic-continuingoperations

.................$0.45$0.40$1.42$0.12$0.40$0.62$1.21$0.19Earnings(loss)percommonshare-basic-discontinuedoperations

................-0.21---(0.01)-0.01Earningspercommonshare-basic

........$0.45$0.61$1.42$0.12$0.40$0.61$1.21$0.20Earningspercommonshare-diluted-continuingoperations

.................$0.45$0.40$1.41$0.12$0.40$0.62$1.20$0.19Earnings(loss)percommonshare-diluted-discontinuedoperations

................-0.21---(0.01)-0.01Earningspercommonshare-diluted

.......$0.45$0.61$1.41$0.12$0.40$0.61$1.20$0.20(a)Thesumofquarterlyamounts,includingpershareamounts,maynotequalamountsreportedforyear-to-dateperiods.Thisisbecauseoftheeffectsofroundingandthechangesinthenumberofweighted-averagedilutedsharesoutstandingeachperiod.AmerenMissouriQuarterended Operating Revenues Operating Income Net Income (Loss)NetIncome(Loss)Availableto Common ShareholderMarch31,2015

.............................$800$115$42$41March31,2014

.............................8171194847June30,2015

..............................

884 146 62 61June30,2014

..............................900243127126September30,2015

.........................

1,171 423 240 239September30,2014

.........................1,097394223222December31,2015

..........................754581111December31,2014..........................73929(5)(5)AmerenIllinois Quarterended Operating Revenues Operating Income Net IncomeNetIncomeAvailableto Common ShareholderMarch31,2015

..................................$745$120$54$53March31,2014..................................7741205453June30,2015

...................................513833231June30,2014...................................519752928September30,2015

..............................6551899898September30,2014..............................5721587575December31,2015

...............................553743332December31,2014...............................633974645ITEM9.CHANGESINANDDISAGREEMENTSWITHACCOUNTANTSONACCOUNTINGANDFINANCIALDISCLOSURE None.137 ITEM9A.CONTROLSANDPROCEDURES(a)EvaluationofDisclosureControlsandProceduresAsofDecember31,2015,evaluationswereperformedunderthesupervisionandwiththeparticipationofmanagement,includingtheprincipalexecutiveofficerandtheprincipalfinancialofficerofeachoftheAmerenCompanies,oftheeffectivenessofthedesignandoperationofsuchregistrant'sdisclosurecontrolsandprocedures(asdefinedinRules13a-15(e)and15d-15(e)oftheExchangeAct).Basedonthoseevaluations,asofDecember31,2015,theprincipalexecutive officerandtheprincipalfinancialofficerofeachoftheAmerenCompaniesconcludedthatsuchdisclosurecontrolsand proceduresareeffectivetoprovideassurancethatinformationrequiredtobedisclosedinsuchregistrant'sreportsfiledor submittedundertheExchangeActisrecorded,processed,summarized,andreportedwithinthetimeperiodsspecifiedinthe SEC'srulesandforms,andthatsuchinformationisaccumulatedandcommunicatedtoitsmanagement,includingitsprincipal executiveandprincipalfinancialofficers,toallowtimelydecisionsregardingrequireddisclosure.(b)Management'sReportonInternalControloverFinancialReportingManagementisresponsibleforestablishingandmaintainingadequateinternalcontroloverfinancialreporting,assuchtermisdefinedinExchangeActRules13a-15(f)and15d-15(f).Underthesupervisionofandwiththeparticipationofmanagement,includingtheprincipalexecutiveofficerandprincipalfinancialofficer,anevaluationwasconductedofthe effectivenessofeachoftheAmerenCompanies'internalcontroloverfinancialreportingbasedontheframeworkin Internal Control-IntegratedFramework(2013)issuedbytheCommitteeofSponsoringOrganizationsoftheTreadwayCommission(COSO).Aftermakingthatevaluation

,managementconcludedthateachoftheAmerenCompanies'internalcontroloverfinancialreportingwaseffectiveasofDecember31,2015.TheeffectivenessofAmeren'sinternalcontroloverfinancial reportingasofDecember31,2015,hasbeenauditedbyPricewaterhouseCoopersLLP,anindependentregisteredpublic accountingfirm,asstatedinitsreporthereinunderPartII,Item8.Thisannualreportdoesnotincludeanattestationreportof AmerenMissouri'sorAmerenIllinois'(theSubsidiaryRegistrants)independentregisteredpublicaccountingfirmregarding internalcontroloverfinancialreporting.Management'sreportforeachoftheSubsidiaryRegistrantsisnotsubjectto attestationbyanindependentregisteredpublicaccountingfirm.Becauseofitsinherentlimitations,internalcontroloverfinancialreportingmaynotpreventordetectmisstatements.Also,projectionsofanyevaluationofeffectivenessintofutureperiodsaresubjecttotheriskthatinternalcontrolsmightbecome inadequatebecauseofchangesinconditions,andtotheriskthatthedegreeofcompliancewiththepoliciesorproceduresmight

deteriorate.(c)ChangeinInternalControlTherehasbeennochangeintheAmerenCompanies'internalcontroloverfinancialreportingduringtheirmostrecentfiscalquarterthathasmateriallyaffected,orisreasonablylikelytomateriallyaffect,theirinternalcontroloverfinancialreporting.ITEM9B.OTHERINFORMATIONTheAmerenCompanieshavenoinformationreportableunderthisitemthatwasrequiredtobedisclosedinareportonSECForm8-Kduringthefourthquarterof2015thathasnotpreviouslybeenreportedonanSECForm8-K.PARTIIIITEM10.DIRECTORS,EXECUTIVEOFFICERS,ANDCORPORATEGOVERNANCEInformationrequiredbyItems401,405,406and407(c)(3),(d)(4)and(d)(5)ofSECRegulationS-KforAmerenwillbeincludedinitsdefinitiveproxystatementfor its2016annualmeetingofshareholdersfiledpursuantto SECRegulation14A;itisincorporatedhereinbyreference.

InformationrequiredbytheseSECRegulationS-Kitemsfor AmerenMissouriandAmerenIllinoiswillbeincludedin eachcompany'sdefinitiveinformationstatementforits 2016annualmeetingofshareholdersfiledpursuanttoSEC Regulation14C;itisincorporatedhereinbyreference.

Specifically,referenceismadetothefollowingsectionsof Ameren'sdefinitiveproxystatementandtoeachofAmeren Missouri'sandAmerenIllinois'definitiveinformation statements:"InformationConcerningNomineestotheBoardofDirectors,""Section16(a)BeneficialOwnership ReportingCompliance,""CorporateGovernance"and "BoardStructure."InformationconcerningexecutiveofficersoftheAmerenCompaniesrequiredbyItem401ofSECRegulation S-Kisreportedunderaseparatecaptionentitled"Executive OfficersoftheRegistrants"inPartIofthisreport.AmerenMissouriandAmerenIllinoisdonothaveseparatelydesignatedstandingauditcommittees,but insteaduseAmeren'sauditandriskcommitteetoperform suchcommitteefunctionsfortheirboardsofdirectors.

ThesecompaniesdonothavesecuritieslistedontheNYSE andthereforearenotsubjecttotheNYSElistingstandards.

138 WalterJ.GalvinservesaschairmanofAmeren'sauditandriskcommitteeandCatherineS.Brune,J.EdwardColeman, andEllenM.Fitzsimmonsserveasmembers.Theboardof directorsofAmerenhasdeterminedthateachofWalterJ.

GalvinandJ.EdwardColemanqualifiesasanaudit committeefinancialexpertandthateachis"independent" asthattermisusedinSECRegulation14A.Also,onthesamebasisasreportedabove,theboardsofdirectorsofAmerenMissouriandAmerenIllinoisusethe nominatingandcorporategovernancecommitteeof Ameren'sboardofdirectorstoperformsuchcommittee functions.Thiscommitteeisresponsibleforthenomination ofdirectorsandforcorporategovernancepractices.

Ameren'snominatingandcorporategovernancecommittee willconsiderdirectornominationsfromshareholdersin accordancewithitsPolicyRegardingNominationsof Directors,whichcanbefoundonAmeren'swebsite:

www.ameren.com.Toencourageethicalconductinitsfinancialmanagementandreporting,Amerenhasadoptedacodeof ethicsthatappliestotheprincipalexecutiveofficer,the president,theprincipalfinancialofficer,theprincipal accountingofficer,thecontroller,andthetreasurerofeach oftheAmerenCompanies.Amerenhasalsoadoptedacode ofbusinessconductthatappliestothedirectors,officers, andemployeesoftheAmerenCompanies.Itisreferredto asthePrinciplesofBusinessConduct.TheAmeren CompaniesmakeavailablefreeofchargethroughAmeren's website(www.ameren.com)theCodeofEthicsandthe PrinciplesofBusinessConduct.Anyamendmenttothe CodeofEthicsorthePrinciplesofBusinessConductand anywaiverfromaprovisionoftheCodeofEthicsorthe PrinciplesofBusinessConductasitrelatestotheprincipal executiveofficer,thepresident,theprincipalfinancial officer,theprincipalaccountingofficer,thecontroller,or thetreasurerofeachoftheAmerenCompanieswillbe postedonAmeren'swebsitewithinfourbusinessdays followingthedateoftheamendmentorwaiver.ITEM11.EXECUTIVECOMPENSATIONInformationrequiredbyItems402and407(e)(4)and(e)(5)ofSECRegulationS-KforAmerenwillbeincludedinitsdefinitiveproxystatementforits2016annualmeetingofshareholdersfiledpursuanttoSECRegulation14A;itisincorporated hereinbyreference.InformationrequiredbytheseSECRegulationS-KitemsforAmerenMissouriandAmerenIllinoiswillbe includedineachcompany'sdefinitiveinformationstatementforits2016annualmeetingofshareholdersfiledpursuanttoSEC Regulation14C;itisincorporatedhereinbyreference.Specifically,referenceismadetothefollowingsectionsofAmeren's definitiveproxystatementandtoeachofAmerenMissouri'sandAmerenIllinois'definitiveinformationstatements:"Executive Compensation"and"HumanResourcesCommitteeInterlocksandInsiderParticipation."ITEM12.SECURITYOWNERSHIPOFCERTAINBENEFICIALOWNERSANDMANAGEMENTANDRELATEDSTOCKHOLDER MATTERSEquityCompensationPlanInformationThefollowingtablepresentsinformationasofDecember31,2015,withrespecttothesharesofAmeren'scommonstockthatmaybeissuedunderitsexistingequitycompensationplans.PlanCategoryColumnANumberofSecuritiesToBeIssuedUponExerciseofOutstandingOptions,WarrantsandRights (b)ColumnB Weighted-AverageExercisePriceofOutstandingOptions,WarrantsandRightsColumnCNumberofSecuritiesRemainingAvailableforFutureIssuanceEquityCompensationPlans(excludingsecuritiesreflectedinColumnA)Equitycompensationplansapprovedbysecurityholders (a).....................3,186,287(c)6,423,549Equitycompensationplansnotapprovedbysecurityholders

......................

---Total.................................

3,186,287 (c)6,423,549(a)Consistsofthe2006IncentivePlanandthe2014IncentivePlan.The2014Planreplacedthe2006PlanforanynewgrantsmadeafterApril24, 2014.(b)Pursuanttograntsofperformanceshareunits(PSUs)underthe2006Plan,1,763,644ofthesecuritiesrepresenttheestimatednumberofPSUsthatwerevestedasofDecember31,2015(includingaccruedandreinvesteddividends),and1,371,732ofthesecuritiesrepresentthetargetnumberofPSUsgrantedbutnotvested(includingaccruedandreinvesteddividends)asofDecember31,2015(includingoutstanding awardsunderthe2014PlanasofDecember31,2015).TheactualnumberofsharesissuedinrespectofthePSUswillvaryfrom0%to200%

ofthetargetlevel,dependingupontheachievementoftotalshareholderreturnobjectivesestablishedforsuchawards.Foradditional informationaboutthePSUs,includingpayoutcalculations,see"CompensationDiscussionandAnalysis-Long-TermIncentives:Performance ShareUnitProgram("PSUP")"inAmeren'sdefinitiveproxystatementforits2016annualmeetingofshareholders,whichwillbefiledpursuant toSECRegulation14A.50,911ofthesecuritiesrepresentsharesthatmaybeissuedasofDecember31,2015,tosatisfyobligationsunderthe AmerenCorporationDeferredCompensationPlanformembersoftheboardofdirectors.(c)EarnedPSUsanddeferredcompensationstockunitsarepaidinsharesofAmerencommonstockonaone-for-onebasis.Accordingly,thePSUsanddeferredcompensationstockunitsdonothaveaweighted-averageexerciseprice.AmerenMissouriandAmerenIllinoisdonothaveseparateequitycompensationplans.

139 SecurityOwnershipofCertainBeneficialOwnersandManagementTheinformationrequiredbyItem403ofSECRegulationS-KforAmerenwillbeincludedinitsdefinitiveproxystatementforits2016annualmeetingofshareholdersfiledpursuanttoSECRegulation14A;itisincorporatedhereinbyreference.InformationrequiredbythisSECRegulationS-KitemforAmerenMissouriandAmerenIllinoiswillbeincludedineach company'sdefinitiveinformationstatementforits2016annualmeetingofshareholdersfiledpursuanttoSECRegulation14C; itisincorporatedhereinbyreference.Specifically,referenceismadetothefollowingsectionofAmeren'sdefinitiveproxy statementandeachofAmerenMissouri'sandAmerenIllinois'definitiveinformationstatement:"SecurityOwnership."ITEM13.CERTAINRELATIONSHIPSANDRELATEDTRANSACTIONSANDDIRECTORINDEPENDENCEInformationrequiredbyItems404and407(a)ofSECRegulationS-KforAmerenwillbeincludedinitsdefinitiveproxystatementforits2016annualmeetingofshareholdersfiledpursuanttoSECRegulation14A;itisincorporatedhereinby reference.InformationrequiredbytheseSECRegulationS-KitemsforAmerenMissouriandAmerenIllinoiswillbeincludedin eachcompany'sdefinitiveinformationstatementforits2016annualmeetingofshareholdersfiledpursuanttoSECRegulation14C;itisincorporatedhereinbyreference.Specifically,referenceismadetothefollowingsectionsofAmeren'sdefinitive proxystatementandtoeachofAmerenMissouri'sandAmerenIllinois'definitiveinformationstatements:"Policyand ProceduresWithRespecttoRelatedPersonTransactions"and"DirectorIndependence."ITEM14.PRINCIPALACCOUNTINGFEESANDSERVICESInformationrequiredbyItem9(e)ofSECSchedule14AfortheAmerenCompanieswillbeincludedinthedefinitiveproxystatementofAmerenandthedefinitiveinformationstatementsofAmerenMissouriandAmerenIllinoisfortheir2016annualmeetingsofshareholdersfiledpursuanttoSECRegulations14Aand14C,respectively;itisincorporatedhereinbyreference.

Specifically,referenceismadetothefollowingsectionofAmeren'sdefinitiveproxystatementandeachofAmerenMissouri's andAmerenIllinois'definitiveinformationstatement:"IndependentRegisteredPublicAccountingFirm."

140 PARTIVITEM15.EXHIBITSANDFINANCIALSTATEMENTSCHEDULESPageNo.(a)(1)FinancialStatements AmerenReportofIndependentRegisteredPublicAccountingFirm...........................................................67ConsolidatedStatementofIncome(Loss)-YearsEndedDecember31,2015,2014,and2013..............................69ConsolidatedStatementofComprehensiveIncome(Loss)-YearsEndedDecember31,2015,2014,and2013.................70ConsolidatedBalanceSheet-December31,2015and2014.........................................................71ConsolidatedStatementofCashFlows-YearsEndedDecember31,2015,2014,and2013.................................72ConsolidatedStatementofShareholders'Equity-YearsEndedDecember31,2015,2014,and2013.........................73AmerenMissouri ReportofIndependentRegisteredPublicAccountingFirm...........................................................68StatementofIncomeandComprehensiveIncome-YearsEndedDecember31,2015,2014,and2013........................74BalanceSheet-December31,2015and2014....................................................................75StatementofCashFlows-YearsEndedDecember31,2015,2014,and2013...........................................76StatementofShareholders'Equity-YearsEndedDecember31,2015,2014,and2013....................................77AmerenIllinois ReportofIndependentRegisteredPublicAccountingFirm...........................................................68StatementofIncomeandComprehensiveIncome-YearsEndedDecember31,2015,2014,and2013........................78BalanceSheet-December31,2015and2014....................................................................79StatementofCashFlows-YearsEndedDecember31,2015,2014,and2013...........................................80StatementofShareholders'Equity-YearsEndedDecember31,2015,2014,and2013....................................81(a)(2)FinancialStatementSchedulesScheduleI-CondensedFinancialInformationofParent-Ameren:CondensedStatementofIncome(Loss)andComprehensiveIncome(Loss)-YearsEndedDecember31,2015,2014,and 2013................................................................................................142CondensedBalanceSheet-December31,2015and2014........................................................142CondensedStatementofCashFlows-YearsEndedDecember31,2015,2014,and2013................................143ScheduleII-ValuationandQualifyingAccountsfortheyearsendedDecember31,2015,2014,and2013.....................145ScheduleIandIIshouldbereadinconjunctionwiththeaforementionedfinancialstatements.Certainscheduleshavebeenomittedbecausetheyarenotapplicableorbecausetherequireddataisshownintheaforementionedfinancial statements.(a)(3)Exhibits-referenceismadetotheExhibitIndex

...........................................

149(b)ExhibitIndex

.......................................................................

149 141 SCHEDULEI-CONDENSEDFINANCIALINFORMATIONOFPARENTAMERENCORPORATIONCONDENSEDSTATEMENTOFINCOMEANDCOMPREHENSIVEINCOMEFortheYearsEndedDecember31,2015,2014,and2013(Inmillions)201520142013Operatingrevenues

................................................................

$-$-$-Operatingexpenses

................................................................

141126Operatingloss

....................................................................

(14)(11)(26)Equityinearningsofsubsidiaries

.....................................................

600607546Interestincomefromaffiliates

........................................................

6 33Totalotherincome(expense),net

.....................................................

(5)2(5)Interestcharges

...................................................................

31642Incometax(benefit)

................................................................

5(2)(36)NetIncomeAttributabletoAmerenCommonShareholders-ContinuingOperations

..............

579587512NetIncome(Loss)AttributabletoAmerenCommonShareholders-DiscontinuedOperations

.......51(1)(223)NetIncomeAttributabletoAmerenCommonShareholders

..................................$630$586$289NetIncomeAttributabletoAmerenCommonShareholders-ContinuingOperations

..............$579$587$512OtherComprehensiveIncome,NetofTaxes:Pensionandotherpostretirementbenefitplanactivity,netofincometaxes(benefit)of$3,$(7),and$16,respectively

.........................................................

6(12)30ComprehensiveIncomefromContinuingOperationsAttributabletoAmerenCommon Shareholders

...................................................................

585575542NetIncome(Loss)AttributabletoAmerenCommonShareholders-DiscontinuedOperations

.......51(1)(223)OtherComprehensiveLossfromDiscontinuedOperations,NetofIncometaxes

.................

--(19)ComprehensiveIncome(Loss)fromDiscontinuedOperationsAttributabletoAmerenCommon Shareholders

...................................................................

51(1)(242)ComprehensiveIncomeAttributabletoAmerenCommonShareholders

........................$636$574$300SCHEDULEI-CONDENSEDFINANCIALINFORMATIONOFPARENTAMERENCORPORATIONCONDENSEDBALANCESHEET(Inmillions)December31,2015December31,2014 Assets:Cashandcashequivalents

..........................................................

$-$1Advancestomoneypool

............................................................

-55Accountsreceivable-affiliates

.......................................................

53 28Notesreceivable-affiliates

..........................................................

-94Miscellaneousaccountsandnotesreceivable

............................................

3 39Othercurrentassets

...............................................................

9 14Totalcurrentassets

..............................................................

65 231Investmentsinsubsidiaries-continuingoperations

......................................

7,231 6,680Investmentinsubsidiary-discontinuedoperations

.......................................

(4)(4)Notereceivable-ATXI

.............................................................

290 100Accumulateddeferredincometaxes,net

...............................................

426 407Otherassets

.....................................................................

158 152Totalassets

........................................................................$8,166$7,566LiabilitiesandShareholders'Equity:Short-termdebt

..................................................................

301 585Borrowingsfrommoneypool

........................................................

14-Accountspayable-affiliates

.........................................................

75 88Othercurrentliabilities

.............................................................

22 52Totalcurrentliabilities

............................................................

412 725Long-termdebt

...................................................................

694-Pensionandotherpostretirementbenefits

..............................................

33 47Otherdeferredcreditsandliabilities

...................................................

81 81Totalliabilities

..................................................................

1,220 853CommitmentsandContingencies(Notes4and5)Shareholders'Equity:Commonstock,$.01parvalue,400.0sharesauthorized-sharesoutstandingof242.6

...........

2 2Otherpaid-incapital,principallypremiumoncommonstock

................................

5,616 5,617Retainedearnings

.................................................................

1,331 1,103Accumulatedothercomprehensiveloss

................................................

(3)(9)Totalshareholders'equity

.........................................................

6,946 6,713 Totalliabilitiesandshareholders'equity

..................................................$8,166$7,566 142 SCHEDULEI-CONDENSEDFINANCIALINFORMATIONOFPARENTAMERENCORPORATIONCONDENSEDSTATEMENTOFCASHFLOWSFortheYearsEndedDecember31,2015,2014,and2013(Inmillions)201520142013Netcashflowsprovidedbyoperatingactivities

..............................................$537$514$453Cashflowsfrominvestingactivities:Moneypooladvances,net

............................................................

55279(371)Notesreceivable-affiliates,net

........................................................

(96)(134)(23)Investmentsinsubsidiaries

...........................................................

(509)(280)(50)Distributionsfromsubsidiaries

.........................................................

-2151Proceedsfromnotereceivable-MarketingCompany

.......................................

20956Contributionstonotereceivable-MarketingCompany

......................................

(8)(89)(5)Other.............................................................................

(24)(12)(3)Netcashflowsprovidedby(usedin)investingactivities

.......................................

(562)74(445)Cashflowsfromfinancingactivities:Dividendsoncommonstock

...........................................................

(402)(390)(388)Short-termdebt,net

.................................................................

(284)217368Moneypoolborrowings,net

...........................................................

14--Maturitiesoflong-termdebt

...........................................................

-(425)-Issuancesoflong-termdebt

...........................................................

700--Capitalissuancecosts

................................................................

(6)--Other.............................................................................

2--Netcashflowsprovidedby(usedin)financingactivities

.......................................

24(598)(20)Netchangeincashandcashequivalents

...................................................$(1)$(10)$(12)Cashandcashequivalentsatbeginningofyear

..............................................

11123Cashandcashequivalentsatendofyear

...................................................

$-$1$11Cashdividendsreceivedfromconsolidatedsubsidiaries

.......................................$575$340$570Noncashinvestingactivity-divestiture

....................................................

$-$-$494Noncashinvestingactivity-investmentsinsubsidiaries

.......................................

(38)(19)-AMERENCORPORATION(parentcompanyonly)NOTESTOCONDENSEDFINANCIALSTATEMENTSDecember31,2015NOTE1-BASISOFPRESENTATIONAmerenCorporation(parentcompanyonly)isapublicutilityholdingcompanythatconductssubstantiallyallofitsbusinessoperationsthroughitssubsidiaries.Inaccordancewithauthoritativeaccountingguidance,AmerenCorporation(parentcompanyonly)hasaccountedforwhollyownedsubsidiariesusingtheequitymethod.Thesefinancialstatementsarepresentedonacondensedbasis.SeeNote1-SummaryofSignificantAccountingPoliciesunderPartII,Item8,ofthisreportforadditionalinformation.AccountingChangesandOtherMattersPresentationofDebtIssuanceCostsDuring2015,theFASBissuedauthoritativeaccountingguidancerequiringdebtissuancecoststobepresentedasareductiontotheassociateddebtliability.Previously,debtissuancecostswerepresentedin"Otherassets"onAmerenCorporation's(parentcompanyonly)balancesheet.AmerenCorporation(parentcompanyonly)earlyadoptedthisstandardin 2015.RetrospectiveapplicationofthenewguidancehadnoimpactonAmerenCorporation's(parentcompanyonly)balance sheetatDecember31,2014.SeeNote5-Long-termDebtandEquityFinancingsunderPartII,Item8,ofthisreportfor additionalinformation.BalanceSheetClassificationofDeferredIncomeTaxesDuring2015,theFASBissuedauthoritativeaccountingguidancerequiringalldeferredtaxassetsandliabilities,alongwithanyrelatedvaluationallowances,tobeclassifiedasnoncurrentonthebalancesheet.Previously,thecurrentportionofdeferredtaxeswaspresentedas"Currentaccumulateddeferredincometaxes,net"andthenoncurrentportionofdeferred taxeswaspresentedas"Accumulateddeferredincometaxes,net"onAmerenCorporation's(parentcompanyonly)balance sheet.AmerenCorporation(parentcompanyonly)earlyadoptedthisstandardin2015andappliedtheguidance retrospectively.AtDecember31,2014,thecurrentportionofdeferredincometaxesof$143millionpreviouslypresentedas "Currentaccumulateddeferredincometaxes,net"onAmerenCorporation's(parentcompanyonly)balancesheetwas reclassifiedandpresentedin"Accumulateddeferredincometaxes,net"forcomparativepurposes.

143 AdditionaldisclosuresrelatingtotheparentcompanyfinancialstatementsareincludedwithinthecombinednotesunderPartII,Item8,ofthisreport.SeeNote1-SummaryofSignificantAccountingPoliciesandNote14-RelatedPartyTransactionsunderPartII,Item8,ofthisreportforinformationonthetaxallocationagreementbetweenAmerenCorporation (parentcompanyonly)anditssubsidiaries.NOTE2-SHORT-TERMDEBTANDLIQUIDITYAmeren,AmerenServices,andothernon-state-regulatedAmerensubsidiarieshavetheability,subjecttoAmerenparentcompanyandapplicableregulatoryshort-termborrowingauthorizations,toaccessfundingfromtheCreditAgreementsandthecommercialpaperprogramsthroughanon-state-regulatedsubsidiarymoneypoolagreement.Allparticipantsmayborrow fromorlendtothenon-state-regulatedmoneypool.Thetotalamountavailabletopoolparticipantsfromthenon-state-regulatedsubsidiarymoneypoolatanygiventimeisreducedbytheamountofborrowingsmadebyparticipants,butis increasedtotheextentthatthepoolparticipantsadvancesurplusfundstothenon-state-regulatedsubsidiarymoneypoolor remitfundsfromotherexternalsources.Thenon-state-regulatedsubsidiarymoneypoolwasestablishedtocoordinateandto provideshort-termcashandworkingcapitalfortheparticipants.Participantsreceivingaloanunderthenon-state-regulated subsidiarymoneypoolagreementmustrepaytheprincipalamountofsuchloan,togetherwithaccruedinterest.Therateof interestdependsonthecompositionofinternalandexternalfundsinthenon-state-regulatedsubsidiarymoneypool.Interest revenuesandinterestchargesrelatedtonon-state-regulatedmoneypooladvancesandborrowingswereimmaterialin2014 and2015.AmerenCorporation(parentcompanyonly)hadatotalof$36millioninguaranteesoutstandingprimarilyforATXIthatwerenotrecordedonitsDecember31,2015balancesheet.TheATXIguaranteeswereissuedtolocalgovernmentsas assuranceforpotentialremediationofdamagecausedbyATXIconstruction.SeeNote4-Short-termDebtandLiquidityunderPartII,Item8,ofthisreportforadescriptionanddetailsofshort-termdebtandliquidityneedsofAmerenCorporation(parentcompanyonly).NOTE3-LONG-TERMOBLIGATIONSInNovember2015,AmerenCorporation(parentcompanyonly)issued$350millionof2.70%seniorunsecurednotesdueNovember15,2020,withinterestpayablesemiannuallyonMay15andNovember15ofeachyear,beginningMay15,2016.Ameren(parent)receivedproceedsof$348million,whichwereusedtorepayaportionofshort-termdebt.InNovember2015,AmerenCorporation(parentcompanyonly)issued$350millionof3.65%seniorunsecurednotesdueFebruary15,2026,withinterestpayablesemiannuallyonFebruary15andAugust15ofeachyear,beginningFebruary15, 2016.Ameren(parent)receivedproceedsof$347million,whichwereusedtorepayaportionofshort-termdebt.InMay2014,AmerenCorporation(parentcompanyonly)repaidatmaturity$425millionofits8.875%seniorunsecurednotes,plusaccruedinterest.Thenoteswererepaidwithproceedsfromcommercialpaperissuances.SeeNote5-Long-termDebtandEquityFinancingsunderPartII,Item8,ofthisreportforadditionalinformationonAmerenCorporation's(parentcompanyonly)long-termdebt.NOTE4-COMMITMENTSANDCONTINGENCIESSeeNote15-CommitmentsandContingenciesunderPartII,Item8,ofthisreportforadescriptionofallmaterialcontingenciesofAmerenCorporation(parentcompanyonly).

NOTE5-DIVESTITURETRANSACTIONSANDDISCONTINUEDOPERATIONSOnDecember2,2013,AmerencompletedthedivestitureofNewAERtoIPHinaccordancewiththetransactionagreementbetweenAmerenandIPHdatedMarch14,2013,asamendedbyaletteragreementdatedDecember2,2013.Asaresultofthedivestiturein2013,AmerenCorporation(parentcompanyonly)recordedapretaxlossondisposalof

$201million.Thischargewasincludedwithin"NetLossAttributabletoAmerenCommonShareholders-Discontinued Operations"intheAmerenCorporation(parentcompanyonly)CondensedStatementofIncome(Loss)andComprehensive Income(Loss)fortheyearendedDecember31,2013.During2015,basedonthecompletionoftheIRSaudit,AmerenCorporation(parentcompanyonly)removeda$53millionreserveforunrecognizedtaxbenefitsrecordedin2013andrecognizedataxbenefitfromdiscontinuedoperations.

SeeNote13-IncomeTaxesunderPartII,Item8,ofthisreportforadditionalinformationregardingAmerenCorporation's (parentcompanyonly)uncertaintaxpositions.In2015,Amerenpaid$25millionrelatedtoapreviously-recordedliabilitypursuanttothetransactionagreementbetweenAmerenandIPHwithnoresultingadditionalimpacttoitsresultsofoperations.SeeNote16-DivestitureTransactionsandDiscontinuedOperationsunderPartII,Item8,ofthisreportforadditionalinformationregardingthedivestituretransactionsanddiscontinuedoperations.

144 SCHEDULEII-VALUATIONANDQUALIFYINGACCOUNTSFORTHEYEARSENDEDDECEMBER31,2015,2014,AND2013(inmillions)ColumnAColumnBColumnCColumnDColumnE DescriptionBalanceat BeginningofPeriod (1)ChargedtoCostsandExpenses (2)ChargedtoOther Accounts (a)Deductions (b)BalanceatEndofPeriod Ameren:Deductedfromassets-allowancefordoubtfulaccounts:

2015.......................................$21$33$5$40$19 2014.......................................183643721 2013.......................................173543818Deferredtaxvaluationallowance:

2015.......................................$10$4$(8)$-$6 2014.......................................73--10 2013.......................................25--7AmerenMissouri:Deductedfromassets-allowancefordoubtfulaccounts:

2015.......................................$8$13$-$14$7 2014.......................................516-138 2013.......................................516-165Deferredtaxvaluationallowance:

2015.......................................$1$-$(1)$-$-

2014.......................................1---1 2013.......................................1---1AmerenIllinois:Deductedfromassets-allowancefordoubtfulaccounts:

2015.......................................$13$20$5$26$12 2014.......................................132042413 2013.......................................121942213Deferredtaxvaluationallowance:

2015.......................................$1$-$(1)$-$-

2014.......................................1---1 2013.......................................1---1(a)AmountsassociatedwiththeallowancefordoubtfulaccountsrelatetotheuncollectibleaccountreserveassociatedwithreceivablespurchasedbyAmerenIllinoisfromalternativeretailelectricsuppliers,asrequiredbytheIllinoisPublicUtilitiesAct.Theamountsrelatingtothedeferredtaxvaluationallowanceareforitemsthathaveexpiredandwereremovedfromboththeunderlyingaccumulateddeferredincometaxaccount aswellastheoffsettingvaluationaccount.(b)Uncollectibleaccountschargedoff,lessrecoveries.

145 SIGNATURESPursuanttotherequirementsofSection13or15(d)oftheSecuritiesExchangeActof1934,eachregistranthasdulycausedthisreporttobesignedonitsbehalfbytheundersigned,thereuntodulyauthorized.Thesignaturesforeachundersignedcompanyshallbedeemedtorelateonlytomattershavingreferencetosuchcompanyoritssubsidiaries.AMERENCORPORATION (registrant)Date:February26,2016 By/s/WarnerL.BaxterWarnerL.Baxter Chairman,PresidentandChiefExecutiveOfficerPursuanttotherequirementsoftheSecuritiesExchangeActof1934,thisreporthasbeensignedbelowbythefollowingpersonsonbehalfoftheregistrantandinthecapacitiesandonthedateindicated./s/WarnerL.BaxterWarnerL.BaxterChairman,PresidentandChiefExecutiveOfficer,andDirector (PrincipalExecutiveOfficer)February26,2016/s/MartinJ.Lyons,Jr.MartinJ.Lyons,Jr.ExecutiveVicePresidentand ChiefFinancialOfficer (PrincipalFinancialOfficer)February26,2016/s/BruceA.SteinkeBruceA.SteinkeSeniorVicePresident,Finance,and ChiefAccountingOfficer (PrincipalAccountingOfficer)February26,2016

  • CatherineS.BruneDirectorFebruary26,2016
  • J.EdwardColemanDirectorFebruary26,2016
  • EllenM.FitzsimmonsDirectorFebruary26,2016
  • RafaelFloresDirectorFebruary26,2016
  • WalterJ.GalvinDirectorFebruary26,2016
  • RichardJ.HarshmanDirectorFebruary26,2016
  • GayleP.W.JacksonDirectorFebruary26,2016
  • JamesC.JohnsonDirectorFebruary26,2016
  • StevenH.LipsteinDirectorFebruary26,2016
  • StephenR.WilsonDirectorFebruary26,2016
  • JackD.WoodardDirectorFebruary26,2016*By/s/MartinJ.Lyons,Jr.MartinJ.Lyons,Jr.

Attorney-in-FactFebruary26,2016 146 UNIONELECTRICCOMPANY (registrant)Date:February26,2016 By/s/MichaelL.MoehnMichaelL.MoehnChairmanandPresidentPursuanttotherequirementsoftheSecuritiesExchangeActof1934,thisreporthasbeensignedbelowbythefollowingpersonsonbehalfoftheregistrantandinthecapacitiesandonthedateindicated./s/MichaelL.MoehnMichaelL.MoehnChairmanandPresident,andDirector(PrincipalExecutiveOfficer)February26,2016/s/MartinJ.Lyons,Jr.MartinJ.Lyons,Jr.ExecutiveVicePresidentand ChiefFinancialOfficer,andDirector (PrincipalFinancialOfficer)February26,2016/s/BruceA.SteinkeBruceA.SteinkeSeniorVicePresident,Financeand ChiefAccountingOfficer (PrincipalAccountingOfficer)February26,2016

  • DanielF.Cole DirectorFebruary26,2016
  • FadiM.Diya DirectorFebruary26,2016
  • GregoryL.Nelson DirectorFebruary26,2016*By/s/MartinJ.Lyons,Jr.MartinJ.Lyons,Jr.

Attorney-in-FactFebruary26,2016 147 AMERENILLINOISCOMPANY (registrant)Date:February26,2016 By/s/RichardJ.MarkRichardJ.MarkChairmanandPresidentPursuanttotherequirementsoftheSecuritiesExchangeActof1934,thisreporthasbeensignedbelowbythefollowingpersonsonbehalfoftheregistrantandinthecapacitiesandonthedateindicated./s/RichardJ.MarkRichardJ.MarkChairmanandPresident,andDirector(PrincipalExecutiveOfficer)February26,2016/s/MartinJ.Lyons,Jr.MartinJ.Lyons,Jr.ExecutiveVicePresidentand ChiefFinancialOfficer,andDirector (PrincipalFinancialOfficer)February26,2016/s/BruceA.SteinkeBruceA.SteinkeSeniorVicePresident,Financeand ChiefAccountingOfficer (PrincipalAccountingOfficer)February26,2016

  • DanielF.ColeDirectorFebruary26,2016
  • CraigD.NelsonDirectorFebruary26,2016
  • GregoryL.NelsonDirectorFebruary26,2016*By/s/MartinJ.Lyons,Jr.MartinJ.Lyons,Jr.

Attorney-in-FactFebruary26,2016 148 EXHIBITINDEXThedocumentslistedbelowarebeingfiledorhavepreviouslybeenfiledonbehalfoftheAmerenCompaniesandareincorporatedhereinbyreferencefromthedocumentsindicatedandmadeaparthereof.Exhibitsnotidentifiedaspreviouslyfiledarefiledherewith:ExhibitDesignationRegistrant(s)NatureofExhibitPreviouslyFiledasExhibitto:PlanofAcquisition,Reorganization,Arrangement,LiquidationorSuccession 2.1 AmerenTransactionAgreement,datedasofMarch14,2013,betweenAmeren CorporationandIllinoisPowerHoldings,LLCMarch19,2013Form8-K,Exhibit2.1, FileNo.1-147562.2AmerenLetterAgreement,datedDecember2,2013,betweenAmerenCorporationandIllinois PowerHoldings,LLC,amendingthe TransactionAgreement,datedasof March14,2013December4,2013Form8-K,Exhibit2.2, FileNo.1-14756ArticlesofIncorporation/By-Laws 3.1(i)AmerenRestatedArticlesofIncorporationof

AmerenAnnexFtoPartIoftheRegistration StatementonFormS-4,FileNo.33-64165 3.2(i)AmerenCertificateofAmendmenttoAmeren's RestatedArticlesofIncorporationfiled December14,19981998Form10-K,Exhibit3(i),

FileNo.1-14756 3.3(i)AmerenCertificateofAmendmenttoAmeren's RestatedArticlesofIncorporationfiled April21,2011April21,2011Form8-K,Exhibit3(i),

FileNo.1-14756 3.4(i)AmerenCertificateofAmendmenttoAmeren's RestatedArticlesofIncorporationfiled December18,2012December18,2012Form8-K, Exhibit3.1(i),FileNo.1-14756 3.5(i)AmerenMissouriRestatedArticlesofIncorporationofAmerenMissouri1993Form10-K,Exhibit3(i),

FileNo.1-2967 3.6(i)AmerenIllinoisRestatedArticlesofIncorporationof AmerenIllinois2010Form10-K,Exhibit3.4(i),

FileNo.1-36723.7(ii)AmerenBy-LawsofAmeren,asamended December11,2015December11,2015Form8-K,Exhibit3.1, FileNo.1-147563.8(ii)AmerenMissouriBylawsofAmerenMissouri,asamendedDecember12,2014December18,2014Form8-K, Exhibit3.1,FileNo.1-29673.9(ii)AmerenIllinoisBylawsofAmerenIllinois,asamended December12,2014December18,2014Form8-K, Exhibit3.2,FileNo.1-3672InstrumentsDefiningRightsofSecurityHolders,IncludingIndentures 4.1 AmerenIndenture,datedasofDecember1,2001 fromAmerentoTheBankofNewYork MellonTrustCompany,N.A.,assuccessor trustee,relatingtoseniordebtsecurities (AmerenIndenture)Exhibit4.5,FileNo.333-81774

4.2 AmerenFirstSupplementalIndenturetoAmeren

SeniorIndenturedatedasofMay19,2008June30,2008Form10-Q,Exhibit4.1, FileNo.1-14756 4.3 AmerenAmerenIndentureCompanyOrder,dated November24,2015,establishingthe2.70%

SeniorNotesdue2020andthe3.65%

SeniorNotesdue2026(includingtheglobal

notes)November24,2015Form8-K,Exhibits4.3, 4.4and4.5,FileNo.1-14756

4.4 Ameren

AmerenMissouriIndentureofMortgageandDeedofTrust, datedJune15,1937(AmerenMissouri Mortgage),fromAmerenMissouritoThe BankofNewYorkMellon,assuccessor trustee,asamendedMay1,1941,and SecondSupplementalIndenturedated May1,1941ExhibitB-1,FileNo.2-4940 149 ExhibitDesignationRegistrant(s)NatureofExhibitPreviouslyFiledasExhibitto:

4.5 AmerenAmerenMissouriSupplementalIndenturetotheAmeren MissouriMortgagedatedasofJuly1,1956August2,1956Form8-K,Exhibit2, FileNo.1-2967

4.6 Ameren

AmerenMissouriSupplementalIndenturetotheAmeren MissouriMortgagedatedasofApril1, 1971April1971Form8-K,Exhibit6, FileNo.1-2967

4.7 Ameren

AmerenMissouriSupplementalIndenturetotheAmeren MissouriMortgagedatedasofFebruary1, 1974February1974Form8-K,Exhibit3, FileNo.1-2967

4.8 Ameren

AmerenMissouriSupplementalIndenturetotheAmeren MissouriMortgagedatedasofJuly7,1980Exhibit4.6,FileNo.2-69821

4.9 Ameren

AmerenMissouriSupplementalIndenturetotheAmeren MissouriMortgagedatedasofOctober1, 1993,relativetoSeries20281993Form10-K,Exhibit4.8, FileNo.1-2967 4.10 Ameren AmerenMissouriSupplementalIndenturetotheAmeren MissouriMortgagedatedasofFebruary1, 20002000Form10-K,Exhibit4.1, FileNo.1-2967 4.11 Ameren AmerenMissouriSupplementalIndenturetotheAmeren MissouriMortgagedatedAugust15,2002August23,2002Form8-K,Exhibit4.3, FileNo.1-2967 4.12 Ameren AmerenMissouriSupplementalIndenturetotheAmeren MissouriMortgagedatedMarch5,2003, relativetoSeriesBBMarch11,2003Form8-K,Exhibit4.4, FileNo.1-2967 4.13 Ameren AmerenMissouriSupplementalIndenturetotheAmeren MissouriMortgagedatedJuly15,2003, relativetoSeriesDDAugust4,2003Form8-K,Exhibit4.4, FileNo.1-2967 4.14 Ameren AmerenMissouriSupplementalIndenturetotheAmeren MissouriMortgagedatedOctober1,2003, relativetoSeriesEEOctober8,2003Form8-K,Exhibit4.4, FileNo.1-2967 4.15 Ameren AmerenMissouriSupplementalIndenturetotheAmeren MissouriMortgagedatedFebruary1,2004, relativetoSeries2004A(1998A)March31,2004Form10-Q,Exhibit4.1, FileNo.1-2967 4.16 Ameren AmerenMissouriSupplementalIndenturetotheAmeren MissouriMortgagedatedFebruary1,2004, relativetoSeries2004B(1998B)March31,2004Form10-Q,Exhibit4.2, FileNo.1-2967 4.17 Ameren AmerenMissouriSupplementalIndenturetotheAmeren MissouriMortgagedatedFebruary1,2004, relativetoSeries2004C(1998C)March31,2004Form10-Q,Exhibit4.3, FileNo.1-2967 4.18 Ameren AmerenMissouriSupplementalIndenturetotheAmeren MissouriMortgagedatedFebruary1,2004, relativetoSeries2004H(1992)March31,2004Form10-Q,Exhibit4.8, FileNo.1-2967 4.19 Ameren AmerenMissouriSupplementalIndenturetotheAmeren MissouriMortgagedatedMay1,2004 relativetoSeriesFFMay18,2004Form8-K,Exhibit4.4, FileNo.1-2967 4.20 Ameren AmerenMissouriSupplementalIndenturetotheAmeren MissouriMortgagedatedSeptember1, 2004relativetoSeriesGGSeptember23,2004Form8-K,Exhibit4.4, FileNo.1-2967 4.21 Ameren AmerenMissouriSupplementalIndenturetotheAmeren MissouriMortgagedatedJanuary1,2005 relativetoSeriesHHJanuary27,2005Form8-K,Exhibit4.4, FileNo.1-2967 4.22 Ameren Ameren MissouriSupplementalIndenturetotheAmeren

Missouri MortgagedatedJuly1,2005relativetoSeriesIIJuly21,2005Form8-K,Exhibit4.4, FileNo.1-2967 4.23 Ameren AmerenMissouriSupplementalIndenturetotheAmeren MissouriMortgagedatedDecember1, 2005relativetoSeriesJJDecember9,2005Form8-K,Exhibit4.4, FileNo.1-2967 150 ExhibitDesignationRegistrant(s)NatureofExhibitPreviouslyFiledasExhibitto:

4.24 AmerenAmerenMissouriSupplementalIndenturetotheAmeren MissouriMortgagedatedJune1,2007 relativetoSeriesKKJune15,2007Form8-K,Exhibit4.5, FileNo.1-2967 4.25 Ameren AmerenMissouriSupplementalIndenturetotheAmeren MissouriMortgagedatedApril1,2008 relativetoSeriesLLApril8,2008Form8-K,Exhibit4.7, FileNo.1-2967 4.26 Ameren AmerenMissouriSupplementalIndenturetotheAmeren MissouriMortgagedatedJune1,2008 relativetoSeriesMMJune19,2008Form8-K,Exhibit4.5, FileNo.1-2967 4.27 Ameren AmerenMissouriSupplementalIndenturetotheAmeren MissouriMortgagedatedMarch1,2009 relativetoSeriesNNMarch23,2009Form8-K,Exhibit4.5, FileNo.1-2967 4.28 Ameren AmerenMissouriSupplementalIndenturetotheAmeren MissouriMortgagedatedMay15,2012Exhibit4.45,FileNo.333-182258 4.29 Ameren AmerenMissouriSupplementalIndenturetotheAmeren MissouriMortgagedatedSeptember1, 2012relativetoSeriesOOSeptember11,2012Form8-K,Exhibit4.4, FileNo.1-2967 4.30 Ameren AmerenMissouriSupplementalIndenturetotheAmeren MissouriMortgagedatedApril1,2014 relativetoSeriesPPApril4,2014Form8-K,Exhibit4.5, FileNo.1-2967 4.31 Ameren AmerenMissouriSupplementalIndenturetotheAmeren MissouriMortgagedatedMarch15,2015 relativetoSeriesQQApril6,2015Form8-K,Exhibit4.5, FileNo.1-2967 4.32 Ameren AmerenMissouriLoanAgreement,datedasofDecember1, 1992,betweentheMissouriEnvironmental AuthorityandAmerenMissouri,together withIndentureofTrustdatedasof December1,1992,betweentheMissouri EnvironmentalAuthorityandUMBBank, N.A.assuccessortrusteetoMercantile BankofSt.Louis,N.A.1992Form10-K,Exhibit4.38, FileNo.1-2967 4.33 Ameren AmerenMissouriFirstAmendment,datedasofFebruary1, 2004,toLoanAgreementdatedasof December1,1992,betweentheMissouri EnvironmentalAuthorityandAmeren

MissouriMarch31,2004Form10-Q,Exhibit4.10, FileNo.1-2967 4.34 Ameren AmerenMissouriSeries1998ALoanAgreement,datedasof September1,1998,betweentheMissouri EnvironmentalAuthorityandAmeren

MissouriSeptember30,1998Form10-Q, Exhibit4.28,FileNo.1-2967 4.35 Ameren AmerenMissouriFirstAmendment,datedasofFebruary1, 2004,toSeries1998ALoanAgreement datedasofSeptember1,1998,between theMissouriEnvironmentalAuthorityand AmerenMissouriMarch31,2004Form10-Q,Exhibit4.11, FileNo.1-2967 4.36 Ameren AmerenMissouriSeries1998BLoanAgreement,datedasof September1,1998,betweentheMissouri EnvironmentalAuthorityandAmeren

MissouriSeptember30,1998Form10-Q, Exhibit4.29,FileNo.1-2967 4.37 Ameren AmerenMissouriFirstAmendment,datedasofFebruary1, 2004,toSeries1998BLoanAgreement datedasofSeptember1,1998,between theMissouriEnvironmentalAuthorityand AmerenMissouriMarch31,2004Form10-Q,Exhibit4.12, FileNo.1-2967 4.38 Ameren AmerenMissouriSeries1998CLoanAgreement,datedasof September1,1998,betweentheMissouri EnvironmentalAuthorityandAmeren

MissouriSeptember30,1998Form10-Q, Exhibit4.30,FileNo.1-2967 151 ExhibitDesignationRegistrant(s)NatureofExhibitPreviouslyFiledasExhibitto:

4.39 AmerenAmerenMissouriFirstAmendment,datedasofFebruary1, 2004,toSeries1998CLoanAgreement datedasofSeptember1,1998,between theMissouriEnvironmentalAuthorityand AmerenMissouriMarch31,2004Form10-Q,Exhibit4.13, FileNo.1-2967 4.40 Ameren AmerenMissouriIndenture,datedasofAugust15,2002, fromAmerenMissouritoTheBankofNew YorkMellon,assuccessortrustee(relating toseniorsecureddebtsecurities)(Ameren MissouriIndenture)August23,2002Form8-K,Exhibit4.1, FileNo.1-2967 4.41 Ameren AmerenMissouriFirstSupplementalIndenturetotheAmeren MissouriIndenture,datedasofMay15, 2012Exhibit4.48,FileNo.333-182258 4.42 Ameren AmerenMissouriAmerenMissouriIndentureCompany Order,datedMarch10,2003,establishing the5.50%SeniorSecuredNotesdue2034 (includingtheglobalnote)March11,2003Form8-K,Exhibits4.2and 4.3,FileNo.1-2967 4.43 Ameren AmerenMissouriAmerenMissouriIndentureCompany Order,datedJuly28,2003,establishingthe 5.10%SeniorSecuredNotesdue2018 (includingtheglobalnote)August4,2003Form8-K,Exhibits4.2and 4.3,FileNo.1-2967 4.44 Ameren AmerenMissouriAmerenMissouriIndentureCompany Order,datedSeptember1,2004, establishingthe5.10%SeniorSecured Notesdue2019(includingtheglobalnote)September23,2004Form8-K,Exhibits4.2 and4.3,FileNo.1-2967 4.45 Ameren AmerenMissouriAmerenMissouriIndentureCompany Order,datedJanuary27,2005,establishing the5.00%SeniorSecuredNotesdue2020 (includingtheglobalnote)January27,2005Form8-K,Exhibits4.2 and4.3,FileNo.1-2967 4.46 Ameren AmerenMissouriAmerenMissouriIndentureCompany Order,datedJuly21,2005,establishingthe 5.30%SeniorSecuredNotesdue2037 (includingtheglobalnote)July21,2005Form8-K,Exhibits4.2and 4.3,FileNo.1-2967 4.47 Ameren AmerenMissouriAmerenMissouriIndentureCompany Order,datedDecember8,2005, establishingthe5.40%SeniorSecured Notesdue2016(includingtheglobalnote)December9,2005Form8-K,Exhibits4.2 and4.3,FileNo.1-2967 4.48 Ameren AmerenMissouriAmerenMissouriIndentureCompany Order,datedJune15,2007,establishing the6.40%SeniorSecuredNotesdue2017 (includingtheglobalnote)June15,2007Form8-K,Exhibits4.2and 4.3,FileNo.1-2967 4.49 Ameren AmerenMissouriAmerenMissouriIndentureCompany Order,datedApril8,2008,establishingthe 6.00%SeniorSecuredNotesdue2018 (includingtheglobalnote)April8,2008Form8-K,Exhibits4.3and 4.5,FileNo.1-2967 4.50 Ameren AmerenMissouriAmerenMissouriIndentureCompany Order,datedJune19,2008,establishing the6.70%SeniorSecuredNotesdue2019 (includingtheglobalnote)June19,2008Form8-K,Exhibits4.2and 4.3,FileNo.1-2967 4.51 Ameren AmerenMissouriAmerenMissouriIndentureCompany Order,datedMarch20,2009,establishing the8.45%SeniorSecuredNotesdue2039 (includingtheglobalnote)March23,2009Form8-K,Exhibits4.2and 4.3,FileNo.1-2967 4.52 Ameren AmerenMissouriAmerenMissouriIndentureCompany Order,datedSeptember11,2012, establishingthe3.90%SeniorSecured Notesdue2042(includingtheglobalnote)September30,2012Form10-Q,Exhibit4.1 andSeptember11,2012Form8-K, Exhibit4.2,FileNo.1-2967 152 ExhibitDesignationRegistrant(s)NatureofExhibitPreviouslyFiledasExhibitto:

4.53 AmerenAmerenMissouriAmerenMissouriIndentureCompany Order,datedApril4,2014,establishingthe 3.50%SeniorSecuredNotesdue2024 (includingtheglobalnote)April4,2014Form8-K,Exhibits4.2and 4.3,FileNo.1-2967 4.54 Ameren AmerenMissouriAmerenMissouriIndentureCompany Order,datedApril6,2015,establishingthe 3.65%SeniorSecuredNotesdue2045 (includingtheglobalnote)April6,2015Form8-K,Exhibits4.2and 4.3,FileNo.1-2967 4.55 Ameren AmerenIllinoisIndenture,datedasofDecember1,1998, fromCentralIllinoisPublicService Company(nowknownasAmerenIllinois) toTheBankofNewYorkMellonTrust Company,N.A.,assuccessortrustee(CIPS

Indenture)Exhibit4.4,FileNo.333-59438 4.56 Ameren AmerenIllinoisFirstSupplementalIndenturetotheCIPS Indenture,datedasofJune14,2006June19,2006Form8-K,Exhibit4.2, FileNo.1-3672 4.57 Ameren AmerenIllinoisSecondSupplementalIndenturetotheCIPS Indenture,datedasofMarch1,2010Exhibit4.17,FileNo.333-166095 4.58 Ameren AmerenIllinoisThirdSupplementalIndenturetotheCIPS Indenture,datedasofOctober1,20102010Form10-K,Exhibit4.59, FileNo.1-3672 4.59 Ameren AmerenIllinoisAmerenIllinoisGlobalNote,dated October1,2010,representingCIPS IndentureSeniorNotes,6.125%due20282010Form10-K,Exhibit4.60, FileNo.1-3672 4.60 Ameren AmerenIllinoisAmerenIllinoisGlobalNote,dated October1,2010,representingCIPS IndentureSeniorNotes,6.70%Series SecuredNotesdue20362010Form10-K,Exhibit4.62, FileNo.1-3672 4.61 Ameren AmerenIllinoisIndentureofMortgageandDeedofTrust betweenIllinoisPowerCompany (predecessorininteresttoCILCOand AmerenIllinois)andBankersTrust Company(nowknownasDeutscheBank TrustCompanyAmericas),astrustee,dated asofApril1,1933(CILCOMortgage),

SupplementalIndenturebetweenthesame partiesdatedasofJune30,1933, SupplementalIndenturebetweenCILCO (predecessorininteresttoAmerenIllinois) andthetrustee,datedasofJuly1,1933, SupplementalIndenturebetweenthesame partiesdatedasofJanuary1,1935,and SupplementalIndenturebetweenthesame partiesdatedasofApril1,1940ExhibitB-1,RegistrationNo.2-1937; ExhibitB-1(a),RegistrationNo.2-2093;and ExhibitA,April1940Form8-K, FileNo.1-2732 4.62 Ameren AmerenIllinoisSupplementalIndenturetotheCILCO Mortgage,datedDecember1,1949December1949Form8-K,ExhibitA, FileNo.1-2732 4.63 Ameren AmerenIllinoisSupplementalIndenturetotheCILCO Mortgage,datedJuly1,1957July1957Form8-K,ExhibitA, FileNo.1-2732 4.64 Ameren AmerenIllinoisSupplementalIndenturetotheCILCO Mortgage,datedFebruary1,1966February1966Form8-K,ExhibitA, FileNo.1-2732 4.65 Ameren AmerenIllinoisSupplementalIndenturetotheCILCO Mortgage,datedJanuary15,1992January30,1992Form8-K,Exhibit4(b),

FileNo.1-2732 4.66 Ameren AmerenIllinoisSupplementalIndenturetotheCILCO Mortgage,datedJune1,2006forthe SeriesAAandBBJune19,2006Form8-K,Exhibit4.11, FileNo.1-2732 4.67 Ameren AmerenIllinoisSupplementalIndenturetotheCILCO Mortgage,datedasofOctober1,2010October7,2010Form8K,Exhibit4.4, FileNo.1-14756 153 ExhibitDesignationRegistrant(s)NatureofExhibitPreviouslyFiledasExhibitto:

4.68 AmerenAmerenIllinoisIndenture,datedasofJune1,2006,from CILCO(predecessorininteresttoAmeren Illinois)toTheBankofNewYorkMellon TrustCompany,N.A.,assuccessortrustee (CILCOIndenture)June19,2006Form8-K,Exhibit4.3, FileNo.1-2732 4.69 Ameren AmerenIllinoisFirstSupplementalIndenturetotheCILCO Indenture,datedOctober1,2010October7,2010Form8K,Exhibit4.1, FileNo.1-3672 4.70 Ameren AmerenIllinoisSecondSupplementalIndenturetothe CILCOIndenturedatedasofJuly21,2011September30,2011Form10-Q, Exhibit4.1,FileNo.1-3672 4.71 Ameren AmerenIllinoisCILCOIndentureCompanyOrder,dated June14,2006,establishingthe6.20%

SeniorSecuredNotesdue2016(including theglobalnote)andthe6.70%Senior SecuredNotesdue2036(includingthe globalnote)June19,2006Form8-K,Exhibit4.6, FileNo.1-2732 4.72 Ameren AmerenIllinoisGeneralMortgageIndentureandDeedof Trust,datedasofNovember1,1992 betweenIllinoisPowerCompany (predecessorininteresttoAmerenIllinois) andTheBankofNewYorkMellonTrust Company,N.A.,assuccessortrustee (AmerenIllinoisMortgage)1992Form10-K,Exhibit4(cc),

FileNo.1-3004 4.73 Ameren AmerenIllinoisSupplementalIndenture,datedasof March1,1998,toAmerenIllinoisMortgage forSeriesSExhibit4.41,FileNo.333-71061 4.74 Ameren AmerenIllinoisSupplementalIndenture,datedasof March1,1998,toAmerenIllinoisMortgage forSeriesTExhibit4.42,FileNo.333-71061 4.75 Ameren AmerenIllinoisSupplementalIndentureamendingthe AmerenIllinoisMortgagedatedasof June15,1999June30,1999Form10-Q,Exhibit4.2, FileNo.1-3004 4.76 Ameren AmerenIllinoisSupplementalIndenture,datedasof July15,1999,toAmerenIllinoisMortgage forSeriesUJune30,1999Form10-Q,Exhibit4.4, FileNo.1-3004 4.77 Ameren AmerenIllinoisSupplementalIndentureamendingthe AmerenIllinoisMortgagedatedasof December15,2002December23,2002Form8-K,Exhibit4.1, FileNo.1-3004 4.78 Ameren AmerenIllinoisSupplementalIndenture,datedasof June1,2006,toAmerenIllinoisMortgage forSeriesAAJune19,2006Form8-K,Exhibit4.13, FileNo.1-3004 4.79 Ameren AmerenIllinoisSupplementalIndenture,datedasof November15,2007,toAmerenIllinois MortgageforSeriesBBNovember20,2007Form8-K,Exhibit4.4, FileNo.1-3004 4.80 Ameren AmerenIllinoisSupplementalIndenture,datedasofApril1, 2008,toAmerenIllinoisMortgagefor SeriesCCApril8,2008Form8-K,Exhibit4.9, FileNo.1-3004 4.81 Ameren AmerenIllinoisSupplementalIndenture,datedasof October1,2008,toAmerenIllinois MortgageforSeriesDDOctober23,2008Form8-K,Exhibit4.4, FileNo.1-3004 4.82 Ameren AmerenIllinoisSupplementalIndenture,datedasof October1,2010,toAmerenIllinois MortgageforSeriesCIPS-AA,CIPS-BBand

CIPS-CCOctober7,2010Form8K,Exhibit4.9, FileNo.1-3672 4.83 Ameren AmerenIllinoisSupplementalIndenture,datedasof January15,2011,toAmerenIllinois

MortgageExhibit4.78,FileNo.333-182258 154 ExhibitDesignationRegistrant(s)NatureofExhibitPreviouslyFiledasExhibitto:

4.84 AmerenAmerenIllinoisSupplementalIndenture,datedasof August1,2012,toAmerenIllinois MortgageforSeriesEEAugust20,2012Form8-K,Exhibit4.4, FileNo.1-3672 4.85 Ameren AmerenIllinoisSupplementalIndenture,datedasof December1,2013,toAmerenIllinois MortgageforSeriesFFDecember10,2013Form8-K,Exhibit4.5, FileNo.1-3672 4.86 Ameren AmerenIllinoisSupplementalIndenture,datedasof June1,2014,toAmerenIllinoisMortgage forSeriesGGJune30,2014Form8-K,Exhibit4.5, FileNo.1-3672 4.87 Ameren AmerenIllinoisSupplementalIndenture,datedasof December1,2014,toAmerenIllinois MortgageforSeriesHHDecember10,2014Form8-K,Exhibit4.5, FileNo.1-3672 4.88 Ameren AmerenIllinoisSupplementalIndenture,datedasof December1,2015,toAmerenIllinois MortgageforSeriesIIDecember14,2015Form8-K,Exhibit4.5, FileNo.1-3672 4.89 Ameren AmerenIllinoisIndenture,datedasofJune1,2006,from IP(predecessorininteresttoAmeren Illinois)toTheBankofNewYorkMellon TrustCompany,N.A.,assuccessortrustee (AmerenIllinoisIndenture)June19,2006Form8-K,Exhibit4.4, FileNo.1-3004 4.90 Ameren AmerenIllinoisFirstSupplementalIndenture,datedasof October1,2010,totheAmerenIllinois IndentureforSeriesCIPS-AA,CIPS-BBand

CIPS-CCOctober7,2010Form8K,Exhibit4.5, FileNo.1-14756 4.91 Ameren AmerenIllinoisSecondSupplementalIndenturetothe AmerenIllinoisIndenturedatedasof July21,2011September30,2011Form10-Q, Exhibit4.2,FileNo.1-3672 4.92 Ameren AmerenIllinoisThirdSupplementalIndenturetothe AmerenIllinoisIndenturedatedasof May15,2012Exhibit4.83,FileNo.333-182258 4.93 Ameren AmerenIllinoisAmerenIllinoisIndentureCompanyOrder, datedJune14,2006,establishingthe 6.25%SeniorSecuredNotesdue2016 (includingtheglobalnote)June19,2006Form8-K,Exhibit4.7, FileNo.1-3004 4.94 Ameren AmerenIllinoisAmerenIllinoisIndentureCompanyOrder, datedNovember15,2007,establishingthe 6.125%SeniorSecuredNotesdue2017 (includingtheglobalnote)November20,2007Form8-K,Exhibit4.2, FileNo.1-3004 4.95 Ameren AmerenIllinoisAmerenIllinoisIndentureCompanyOrder, datedApril8,2008,establishingthe6.25%

SeniorSecuredNotesdue2018(including theglobalnote)April8,2008Form8-K,Exhibit4.4, FileNo.1-3004 4.96 Ameren AmerenIllinoisAmerenIllinoisIndentureCompanyOrder datedOctober23,2008,establishingthe 9.75%SeniorSecuredNotesdue2018 (includingtheglobalnote)October23,2008Form8-K,Exhibit4.2, FileNo.1-3004 4.97 Ameren AmerenIllinoisAmerenIllinoisIndentureCompanyOrder datedAugust20,2012,establishingthe 2.70%SeniorSecuredNotesdue2022 (includingtheglobalnote)August20,2012Form8-K,Exhibits4.2and 4.3,FileNo.1-3004 4.98 Ameren AmerenIllinoisAmerenIllinoisIndentureCompanyOrder datedDecember10,2013,establishingthe 4.80%SeniorSecuredNotesdue2043 (includingtheglobalnote)December10,2013Form8-K,Exhibits4.2 and4.3,FileNo.1-3672 4.99 Ameren AmerenIllinoisAmerenIllinoisIndentureCompanyOrder datedJune30,2014,establishingthe 4.30%SeniorSecuredNotesdue2044 (includingtheglobalnote)June30,2014Form8-K,Exhibits4.2and 4.3,FileNo.1-3672 155 ExhibitDesignationRegistrant(s)NatureofExhibitPreviouslyFiledasExhibitto:4.100AmerenAmerenIllinoisAmerenIllinoisIndentureCompanyOrderdatedDecember10,2014,establishingthe 3.25%SeniorSecuredNotesdue2025 (includingtheglobalnote)December10,2014Form8-K,Exhibits4.2 and4.3,FileNo.1-36724.101AmerenAmerenIllinoisAmerenIllinoisIndentureCompanyOrder datedDecember14,2015,establishingthe 4.15%SeniorSecuredNotesdue2046 (includingtheglobalnote)December14,2015Form8-K,Exhibits4.2 and4.3,FileNo.1-3672MaterialContracts 10.1AmerenCompaniesFourthAmendedAmerenCorporationSystemUtilityMoneyPoolAgreement,as amendedJanuary30,2014June30,2015Form10-Q,Exhibit10.1, FileNo.1-14756 10.2 Ameren AmerenMissouriAmendedandRestatedCreditAgreement, datedasofDecember11,2014,byand amongAmeren,AmerenMissouriand JPMorganChaseBank,N.A.,asagent,and thelenderspartythereto.December11,2014Form8-K,Exhibit10.1, FileNo.1-14756 10.3 Ameren AmerenIllinoisAmendedandRestatedCreditAgreement, datedasofDecember11,2014,byand amongAmeren,AmerenIllinoisand JPMorganChaseBank,N.A.,asagent,and thelenderspartythereto.December11,2014Form8-K,Exhibit10.2, FileNo.1-14756 10.4 Ameren*SummarySheetofAmerenCorporation Non-ManagementDirectorCompensation revisedonOctober9,2015andeffectiveas ofJanuary1,2016 10.5 Ameren*Ameren'sDeferredCompensationPlanfor MembersoftheBoardofDirectors amendedandrestatedeffectiveJanuary1, 2009,datedJune13,2008June30,2008Form10-Q,Exhibit10.3, FileNo.1-14756 10.6AmerenCompanies*AmendmentdatedOctober12,2009,toAmeren'sDeferredCompensationPlanfor MembersoftheBoardofDirectors, effectiveJanuary1,20102009Form10-K,Exhibit10.15, FileNo.1-14756 10.7AmerenCompanies*AmendmentdatedOctober14,2010,toAmeren'sDeferredCompensationPlanfor MembersoftheBoardofDirectors2010Form10-K,Exhibit10.15, FileNo.1-14756 10.8AmerenCompanies*Ameren'sDeferredCompensationPlanasamendedandrestatedeffectiveJanuary1, 2010October14,2009Form8-K,Exhibit10.1, FileNo.1-14756 10.9AmerenCompanies*AmendmentdatedOctober14,2010toAmeren'sDeferredCompensationPlan2010Form10-K,Exhibit10.17, FileNo.1-1475610.10AmerenCompanies*2013AmerenExecutiveIncentivePlanDecember18,2012Form8-K,Exhibit10.1,FileNo.1-1475610.11AmerenCompanies*2014AmerenExecutiveIncentivePlanMarch31,2014Form10-Q,Exhibit10.1,FileNo.1-1475610.12AmerenCompanies*2015AmerenExecutiveIncentivePlan2014Form10-K,Exhibit10.13,FileNo.1-1475610.13AmerenCompanies*2016AmerenExecutiveIncentivePlan10.14AmerenCompanies*2013BaseSalaryTableforNamedExecutiveOfficers2012Form10-K,Exhibit10.17,FileNo.1-1475610.15AmerenCompanies*2014BaseSalaryTableforNamedExecutiveOfficers2013Form10-K,Exhibit10.15, FileNo.1-1475610.16AmerenCompanies*2015BaseSalaryTableforNamedExecutiveOfficers2014Form10-K,Exhibit10.17, FileNo.1-14756 156 ExhibitDesignationRegistrant(s)NatureofExhibitPreviouslyFiledasExhibitto:10.17AmerenCompanies*2016BaseSalaryTableforNamedExecutiveOfficers10.18AmerenCompanies*SecondAmendedandRestatedAmerenCorporationChangeofControlSeverance Plan2008Form10-K,Exhibit10.37, FileNo.1-1475610.19AmerenCompanies*FirstAmendmentdatedOctober12,2009,totheSecondAmendedandRestated AmerenChangeofControlSeverancePlanOctober14,2009Form8-K,Exhibit10.2, FileNo.1-1475610.20AmerenCompanies*RevisedScheduleItoSecondAmendedandRestatedAmerenChangeofControl SeverancePlan,asamended10.21AmerenCompanies*FormulaforDetermining2013TargetPerformanceShareUnitAwardstobe IssuedtoNamedExecutiveOfficersDecember18,2012Form8-K,Exhibit99.1, FileNo.1-1475610.22AmerenCompanies*FormulaforDetermining2014TargetPerformanceShareUnitAwardstobe IssuedtoNamedExecutiveOfficersMarch31,2014Form10-Q,Exhibit10.2, FileNo.1-1475610.23AmerenCompanies*FormulaforDetermining2015TargetPerformanceShareUnitAwardstobe IssuedtoNamedExecutiveOfficers2014Form10-K,Exhibit10.17, FileNo.1-1475610.24AmerenCompanies*FormulaforDetermining2016TargetPerformanceShareUnitAwardstobe IssuedtoNamedExecutiveOfficers10.25AmerenCompanies*AmerenCorporation2006OmnibusIncentiveCompensationPlanFebruary16,2006Form8-K,Exhibit10.3, FileNo.1-1475610.26AmerenCompanies*FormofPerformanceShareUnitAwardAgreementforAwardsIssuedin2013 pursuantto2006OmnibusIncentive CompensationPlanDecember18,2012Form8-K,Exhibit10.2, FileNo.1-1475610.27AmerenCompanies*FormofPerformanceShareUnitAwardAgreementforAwardsIssuedin2014 pursuantto2006OmnibusIncentive CompensationPlanMarch31,2014Form10-Q,Exhibit10.3, FileNo.1-1475610.28AmerenCompanies*AmerenCorporation2014OmnibusIncentiveCompensationPlanExhibit99,FileNo.333-19651510.29AmerenCompanies*FormofPerformanceShareUnitAwardAgreementforAwardsIssuedin2014 pursuantto2014OmnibusIncentive CompensationPlan2014Form10-K,Exhibit10.30, FileNo.1-1475610.30AmerenCompanies*FormofPerformanceShareUnitAwardAgreementforAwardsIssuedin2015 pursuantto2014OmnibusIncentive CompensationPlan2014Form10-K,Exhibit10.31, FileNo.1-1475610.31AmerenCompanies*FormofPerformanceShareUnitAwardAgreementforAwardsIssuedin2016 pursuantto2014OmnibusIncentive CompensationPlan10.32AmerenCompanies*AmerenSupplementalRetirementPlanamendedandrestatedeffectiveJanuary1, 2008,datedJune13,2008June30,2008Form10-Q,Exhibit10.1, FileNo.1-1475610.33AmerenCompanies*FirstAmendmenttoamendedandrestatedAmerenSupplementalRetirementPlan, datedOctober24,20082008Form10-K,Exhibit10.44, FileNo.1-1475610.34AmerenAmerenIllinois*CILCOExecutiveDeferralPlanasamended effectiveAugust15,19991999Form10-K,Exhibit10, FileNo.1-2732 157 ExhibitDesignationRegistrant(s)NatureofExhibitPreviouslyFiledasExhibitto:10.35AmerenAmerenIllinois*CILCOExecutiveDeferralPlanIIasamendedeffectiveApril1,19991999Form10-K,Exhibit10(a),

FileNo.1-273210.36AmerenAmerenIllinois*CILCORestructuredExecutiveDeferral Plan(approvedAugust15,1999)1999Form10-K,Exhibit10(e),

FileNo.1-273210.37Ameren*EmploymentandChangeofControl Agreement,datedMarch13,2013,between StevenR.Sullivan,AERandAmerenMarch19,2013Form8-K,Exhibit10.4, FileNo.1-1475610.38Ameren*ConsultingAgreementbetweenCharlesD.

NaslundandAmerenServices,dated March2,2015March31,2015Form10-Q,Exhibit10.1, FileNo.1-14756Statementre:ComputationofRatios 12.1 AmerenAmeren'sStatementofComputationof RatioofEarningstoFixedCharges 12.2AmerenMissouriAmerenMissouri'sStatementofComputationofRatioofEarningstoFixed ChargesandCombinedFixedChargesand PreferredStockDividendRequirements 12.3AmerenIllinoisAmerenIllinois'StatementofComputation ofRatioofEarningstoFixedChargesand CombinedFixedChargesandPreferred StockDividendRequirementsSubsidiariesoftheRegistrant 21.1AmerenCompaniesSubsidiariesofAmerenConsentofExpertsandCounsel 23.1 AmerenConsentofIndependentRegisteredPublic AccountingFirmwithrespecttoAmeren 23.2AmerenMissouriConsentofIndependentRegisteredPublicAccountingFirmwithrespecttoAmeren

Missouri 23.3AmerenIllinoisConsentofIndependentRegisteredPublic AccountingFirmwithrespecttoAmeren

IllinoisPowerofAttorney 24.1 AmerenPowersofAttorneywithrespecttoAmeren 24.2AmerenMissouriPowersofAttorneywithrespecttoAmeren Missouri 24.3AmerenIllinoisPowersofAttorneywithrespecttoAmeren

IllinoisRule13a-14(a)/15d-14(a)Certifications 31.1 AmerenRule13a-14(a)/15d-14(a)Certificationof PrincipalExecutiveOfficerofAmeren 31.2 AmerenRule13a-14(a)/15d-14(a)Certificationof PrincipalFinancialOfficerofAmeren 31.3AmerenMissouriRule13a-14(a)/15d-14(a)CertificationofPrincipalExecutiveOfficerofAmeren

Missouri 31.4AmerenMissouriRule13a-14(a)/15d-14(a)CertificationofPrincipalFinancialOfficerofAmeren

Missouri 31.5AmerenIllinoisRule13a-14(a)/15d-14(a)Certificationof PrincipalExecutiveOfficerofAmeren

Illinois 31.6AmerenIllinoisRule13a-14(a)/15d-14(a)Certificationof PrincipalFinancialOfficerofAmerenIllinois 158 ExhibitDesignationRegistrant(s)NatureofExhibitPreviouslyFiledasExhibitto:Section1350Certifications 32.1 AmerenSection1350CertificationofPrincipalExecutiveOfficerandPrincipalFinancial OfficerofAmeren 32.2AmerenMissouriSection1350CertificationofPrincipalExecutiveOfficerandPrincipalFinancial OfficerofAmerenMissouri 32.3AmerenIllinoisSection1350CertificationofPrincipal ExecutiveOfficerandPrincipalFinancial OfficerofAmerenIllinoisAdditionalExhibits 99.1AmerenCompaniesAmendedandRestatedTaxAllocationAgreement,datedasofNovember21,20132013Form10-K,Exhibit99.1, FileNo.1-14756InteractiveDataFile101.INSAmerenCompaniesXBRLInstanceDocument101.SCHAmerenCompaniesXBRLTaxonomyExtensionSchema Document101.CALAmerenCompaniesXBRLTaxonomyExtensionCalculationLinkbaseDocument101.LABAmerenCompaniesXBRLTaxonomyExtensionLabelLinkbase Document101.PREAmerenCompaniesXBRLTaxonomyExtensionPresentationLinkbaseDocument101.DEFAmerenCompaniesXBRLTaxonomyExtensionDefinition DocumentThefilenumberreferencesfortheAmerenCompanies'filingswiththeSECare:Ameren,1-14756;AmerenMissouri,1-2967;andAmerenIllinois,1-3672.*Compensatoryplanorarrangement.EachregistrantherebyundertakestofurnishtotheSECuponrequestacopyofanylong-termdebtinstrumentnotlistedabovethatsuchregistranthasnotfiledasanexhibitpursuanttotheexemptionprovidedbyItem601(b)(4)(iii)(A)ofRegulationS-K.

159 Exhibit31.1RULE13a-14(a)/15d-14(a)CERTIFICATIONOFPRINCIPALEXECUTIVEOFFICEROFAMERENCORPORATION(requiredbySection302oftheSarbanes-OxleyActof2002)I,WarnerL.Baxter,certifythat:1.IhavereviewedthisreportonForm10-KforthefiscalyearendedDecember31,2015,ofAmerenCorporation; 2.Basedonmyknowledge,thisreportdoesnotcontainanyuntruestatementofamaterialfactoromittostateamaterialfactnecessarytomakethestatementsmade,inlightofthecircumstancesunderwhichsuchstatementsweremade,notmisleadingwithrespecttotheperiodcoveredbythisreport;3.Basedonmyknowledge,thefinancialstatements,andotherfinancialinformationincludedinthisreport,fairlypresentinallmaterialrespectsthefinancialcondition,resultsofoperationsandcashflowsoftheregistrantasof,andfor,the periodspresentedinthisreport;4.Theregistrant'sothercertifyingofficerandIareresponsibleforestablishingandmaintainingdisclosurecontrolsandprocedures(asdefinedinExchangeActRules13a-15(e)and15d-15(e))andinternalcontroloverfinancialreporting(as definedinExchangeActRules13a-15(f)and15d-15(f))fortheregistrantandhave:a)Designedsuchdisclosurecontrolsandprocedures,orcausedsuchdisclosurecontrolsandprocedurestobedesignedunderoursupervision,toensurethatmaterialinformationrelatingtotheregistrant,includingitsconsolidatedsubsidiaries,ismadeknowntousbyotherswithinthoseentities,particularlyduringthe periodinwhichthisreportisbeingprepared;b)Designedsuchinternalcontroloverfinancialreporting,orcausedsuchinternalcontroloverfinancialreportingtobedesignedunderoursupervision,toprovidereasonableassuranceregardingthereliability offinancialreportingandthepreparationoffinancialstatementsforexternalpurposesinaccordancewith generallyacceptedaccountingprinciples;c)Evaluatedtheeffectivenessoftheregistrant'sdisclosurecontrolsandproceduresandpresentedinthisreportourconclusionsabouttheeffectivenessofthedisclosurecontrolsandprocedures,asoftheendof theperiodcoveredbythisreportbasedonsuchevaluation;andd)Disclosedinthisreportanychangeintheregistrant'sinternalcontroloverfinancialreportingthatoccurredduringtheregistrant'smostrecentfiscalquarter(theregistrant'sfourthfiscalquarterinthecase ofanannualreport)thathasmateriallyaffected,orisreasonablylikelytomateriallyaffect,theregistrant'sinternalcontroloverfinancialreporting;and5.Theregistrant'sothercertifyingofficerandIhavedisclosed,basedonourmostrecentevaluationofinternalcontroloverfinancialreporting,totheregistrant'sauditorsandtheauditcommitteeoftheregistrant'sboardofdirectors(orpersonsperformingtheequivalentfunctions):a)Allsignificantdeficienciesandmaterialweaknessesinthedesignoroperationofinternalcontroloverfinancialreportingwhicharereasonablylikelytoadverselyaffecttheregistrant'sabilitytorecord,process,summarizeandreportfinancialinformation;andb)Anyfraud,whetherornotmaterial,thatinvolvesmanagementorotheremployeeswhohaveasignificantroleintheregistrant'sinternalcontroloverfinancialreporting.Date:February26,2016/s/WarnerL.BaxterWarnerL.BaxterChairman,PresidentandChiefExecutiveOfficer (PrincipalExecutiveOfficer)

Exhibit31.2RULE13a-14(a)/15d-14(a)CERTIFICATIONOFPRINCIPALFINANCIALOFFICEROFAMERENCORPORATION(requiredbySection302oftheSarbanes-OxleyActof2002)I,MartinJ.Lyons,Jr.,certifythat:1.IhavereviewedthisreportonForm10-KforthefiscalyearendedDecember31,2015,ofAmerenCorporation; 2.Basedonmyknowledge,thisreportdoesnotcontainanyuntruestatementofamaterialfactoromittostateamaterialfactnecessarytomakethestatementsmade,inlightofthecircumstancesunderwhichsuchstatementsweremade,notmisleadingwithrespecttotheperiodcoveredbythisreport;3.Basedonmyknowledge,thefinancialstatements,andotherfinancialinformationincludedinthisreport,fairlypresentinallmaterialrespectsthefinancialcondition,resultsofoperationsandcashflowsoftheregistrantasof,andfor,the periodspresentedinthisreport;4.Theregistrant'sothercertifyingofficerandIareresponsibleforestablishingandmaintainingdisclosurecontrolsandprocedures(asdefinedinExchangeActRules13a-15(e)and15d-15(e))andinternalcontroloverfinancialreporting(as definedinExchangeActRules13a-15(f)and15d-15(f))fortheregistrantandhave:a)Designedsuchdisclosurecontrolsandprocedures,orcausedsuchdisclosurecontrolsandprocedurestobedesignedunderoursupervision,toensurethatmaterialinformationrelatingtotheregistrant,includingitsconsolidatedsubsidiaries,ismadeknowntousbyotherswithinthoseentities,particularlyduringthe periodinwhichthisreportisbeingprepared;b)Designedsuchinternalcontroloverfinancialreporting,orcausedsuchinternalcontroloverfinancialreportingtobedesignedunderoursupervision,toprovidereasonableassuranceregardingthereliability offinancialreportingandthepreparationoffinancialstatementsforexternalpurposesinaccordancewith generallyacceptedaccountingprinciples;c)Evaluatedtheeffectivenessoftheregistrant'sdisclosurecontrolsandproceduresandpresentedinthisreportourconclusionsabouttheeffectivenessofthedisclosurecontrolsandprocedures,asoftheendof theperiodcoveredbythisreportbasedonsuchevaluation;andd)Disclosedinthisreportanychangeintheregistrant'sinternalcontroloverfinancialreportingthatoccurredduringtheregistrant'smostrecentfiscalquarter(theregistrant'sfourthfiscalquarterinthecase ofanannualreport)thathasmateriallyaffected,orisreasonablylikelytomateriallyaffect,theregistrant'sinternalcontroloverfinancialreporting;and5.Theregistrant'sothercertifyingofficerandIhavedisclosed,basedonourmostrecentevaluationofinternalcontroloverfinancialreporting,totheregistrant'sauditorsandtheauditcommitteeoftheregistrant'sboardofdirectors(orpersonsperformingtheequivalentfunctions):a)Allsignificantdeficienciesandmaterialweaknessesinthedesignoroperationofinternalcontroloverfinancialreportingwhicharereasonablylikelytoadverselyaffecttheregistrant'sabilitytorecord,process,summarizeandreportfinancialinformation;andb)Anyfraud,whetherornotmaterial,thatinvolvesmanagementorotheremployeeswhohaveasignificantroleintheregistrant'sinternalcontroloverfinancialreporting.Date:February26,2016/s/MartinJ.Lyons,Jr.MartinJ.Lyons,Jr.ExecutiveVicePresidentandChiefFinancialOfficer (PrincipalFinancialOfficer)

Exhibit31.3RULE13a-14(a)/15d-14(a)CERTIFICATIONOFPRINCIPALEXECUTIVEOFFICEROFUNIONELECTRICCOMPANY(requiredbySection302oftheSarbanes-OxleyActof2002)I,MichaelL.Moehn,certifythat:1.IhavereviewedthisreportonForm10-KforthefiscalyearendedDecember31,2015,ofUnionElectricCompany; 2.Basedonmyknowledge,thisreportdoesnotcontainanyuntruestatementofamaterialfactoromittostateamaterialfactnecessarytomakethestatementsmade,inlightofthecircumstancesunderwhichsuchstatementsweremade,notmisleadingwithrespecttotheperiodcoveredbythisreport;3.Basedonmyknowledge,thefinancialstatements,andotherfinancialinformationincludedinthisreport,fairlypresentinallmaterialrespectsthefinancialcondition,resultsofoperationsandcashflowsoftheregistrantasof,andfor,the periodspresentedinthisreport;4.Theregistrant'sothercertifyingofficerandIareresponsibleforestablishingandmaintainingdisclosurecontrolsandprocedures(asdefinedinExchangeActRules13a-15(e)and15d-15(e))andinternalcontroloverfinancialreporting(as definedinExchangeActRules13a-15(f)and15d-15(f))fortheregistrantandhave:a)Designedsuchdisclosurecontrolsandprocedures,orcausedsuchdisclosurecontrolsandprocedurestobedesignedunderoursupervision,toensurethatmaterialinformationrelatingtotheregistrant,includingitsconsolidatedsubsidiaries,ismadeknowntousbyotherswithinthoseentities,particularlyduringthe periodinwhichthisreportisbeingprepared;b)Designedsuchinternalcontroloverfinancialreporting,orcausedsuchinternalcontroloverfinancialreportingtobedesignedunderoursupervision,toprovidereasonableassuranceregardingthereliability offinancialreportingandthepreparationoffinancialstatementsforexternalpurposesinaccordancewith generallyacceptedaccountingprinciples;c)Evaluatedtheeffectivenessoftheregistrant'sdisclosurecontrolsandproceduresandpresentedinthisreportourconclusionsabouttheeffectivenessofthedisclosurecontrolsandprocedures,asoftheendof theperiodcoveredbythisreportbasedonsuchevaluation;andd)Disclosedinthisreportanychangeintheregistrant'sinternalcontroloverfinancialreportingthatoccurredduringtheregistrant'smostrecentfiscalquarter(theregistrant'sfourthfiscalquarterinthecase ofanannualreport)thathasmateriallyaffected,orisreasonablylikelytomateriallyaffect,theregistrant'sinternalcontroloverfinancialreporting;and5.Theregistrant'sothercertifyingofficerandIhavedisclosed,basedonourmostrecentevaluationofinternalcontroloverfinancialreporting,totheregistrant'sauditorsandtheauditcommitteeoftheregistrant'sboardofdirectors(orpersonsperformingtheequivalentfunctions):a)Allsignificantdeficienciesandmaterialweaknessesinthedesignoroperationofinternalcontroloverfinancialreportingwhicharereasonablylikelytoadverselyaffecttheregistrant'sabilitytorecord,process,summarizeandreportfinancialinformation;andb)Anyfraud,whetherornotmaterial,thatinvolvesmanagementorotheremployeeswhohaveasignificantroleintheregistrant'sinternalcontroloverfinancialreporting.Date:February26,2016/s/MichaelL.MoehnMichaelL.MoehnChairmanandPresident (PrincipalExecutiveOfficer)

Exhibit31.4RULE13a-14(a)/15d-14(a)CERTIFICATIONOFPRINCIPALFINANCIALOFFICEROFUNIONELECTRICCOMPANY(requiredbySection302oftheSarbanes-OxleyActof2002)I,MartinJ.Lyons,Jr.,certifythat:1.IhavereviewedthisreportonForm10-KforthefiscalyearendedDecember31,2015,ofUnionElectricCompany; 2.Basedonmyknowledge,thisreportdoesnotcontainanyuntruestatementofamaterialfactoromittostateamaterialfactnecessarytomakethestatementsmade,inlightofthecircumstancesunderwhichsuchstatementsweremade,notmisleadingwithrespecttotheperiodcoveredbythisreport;3.Basedonmyknowledge,thefinancialstatements,andotherfinancialinformationincludedinthisreport,fairlypresentinallmaterialrespectsthefinancialcondition,resultsofoperationsandcashflowsoftheregistrantasof,andfor,the periodspresentedinthisreport;4.Theregistrant'sothercertifyingofficerandIareresponsibleforestablishingandmaintainingdisclosurecontrolsandprocedures(asdefinedinExchangeActRules13a-15(e)and15d-15(e))andinternalcontroloverfinancialreporting(as definedinExchangeActRules13a-15(f)and15d-15(f))fortheregistrantandhave:a)Designedsuchdisclosurecontrolsandprocedures,orcausedsuchdisclosurecontrolsandprocedurestobedesignedunderoursupervision,toensurethatmaterialinformationrelatingtotheregistrant,includingitsconsolidatedsubsidiaries,ismadeknowntousbyotherswithinthoseentities,particularlyduringthe periodinwhichthisreportisbeingprepared;b)Designedsuchinternalcontroloverfinancialreporting,orcausedsuchinternalcontroloverfinancialreportingtobedesignedunderoursupervision,toprovidereasonableassuranceregardingthereliability offinancialreportingandthepreparationoffinancialstatementsforexternalpurposesinaccordancewith generallyacceptedaccountingprinciples;c)Evaluatedtheeffectivenessoftheregistrant'sdisclosurecontrolsandproceduresandpresentedinthisreportourconclusionsabouttheeffectivenessofthedisclosurecontrolsandprocedures,asoftheendof theperiodcoveredbythisreportbasedonsuchevaluation;andd)Disclosedinthisreportanychangeintheregistrant'sinternalcontroloverfinancialreportingthatoccurredduringtheregistrant'smostrecentfiscalquarter(theregistrant'sfourthfiscalquarterinthecase ofanannualreport)thathasmateriallyaffected,orisreasonablylikelytomateriallyaffect,theregistrant'sinternalcontroloverfinancialreporting;and5.Theregistrant'sothercertifyingofficerandIhavedisclosed,basedonourmostrecentevaluationofinternalcontroloverfinancialreporting,totheregistrant'sauditorsandtheauditcommitteeoftheregistrant'sboardofdirectors(orpersonsperformingtheequivalentfunctions):a)Allsignificantdeficienciesandmaterialweaknessesinthedesignoroperationofinternalcontroloverfinancialreportingwhicharereasonablylikelytoadverselyaffecttheregistrant'sabilitytorecord,process,summarizeandreportfinancialinformation;andb)Anyfraud,whetherornotmaterial,thatinvolvesmanagementorotheremployeeswhohaveasignificantroleintheregistrant'sinternalcontroloverfinancialreporting.Date:February26,2016/s/MartinJ.Lyons,Jr.MartinJ.Lyons,Jr.ExecutiveVicePresidentandChiefFinancialOfficer (PrincipalFinancialOfficer)

Exhibit31.5RULE13a-14(a)/15d-14(a)CERTIFICATIONOFPRINCIPALEXECUTIVEOFFICEROFAMERENILLINOISCOMPANY(requiredbySection302oftheSarbanes-OxleyActof2002)I,RichardJ.Mark,certifythat:1.IhavereviewedthisreportonForm10-KforthefiscalyearendedDecember31,2015,ofAmerenIllinoisCompany; 2.Basedonmyknowledge,thisreportdoesnotcontainanyuntruestatementofamaterialfactoromittostateamaterialfactnecessarytomakethestatementsmade,inlightofthecircumstancesunderwhichsuchstatementsweremade,notmisleadingwithrespecttotheperiodcoveredbythisreport;3.Basedonmyknowledge,thefinancialstatements,andotherfinancialinformationincludedinthisreport,fairlypresentinallmaterialrespectsthefinancialcondition,resultsofoperationsandcashflowsoftheregistrantasof,andfor,the periodspresentedinthisreport;4.Theregistrant'sothercertifyingofficerandIareresponsibleforestablishingandmaintainingdisclosurecontrolsandprocedures(asdefinedinExchangeActRules13a-15(e)and15d-15(e))andinternalcontroloverfinancialreporting(as definedinExchangeActRules13a-15(f)and15d-15(f))fortheregistrantandhave:a)Designedsuchdisclosurecontrolsandprocedures,orcausedsuchdisclosurecontrolsandprocedurestobedesignedunderoursupervision,toensurethatmaterialinformationrelatingtotheregistrant,includingitsconsolidatedsubsidiaries,ismadeknowntousbyotherswithinthoseentities,particularlyduringthe periodinwhichthisreportisbeingprepared;b)Designedsuchinternalcontroloverfinancialreporting,orcausedsuchinternalcontroloverfinancialreportingtobedesignedunderoursupervision,toprovidereasonableassuranceregardingthereliability offinancialreportingandthepreparationoffinancialstatementsforexternalpurposesinaccordancewith generallyacceptedaccountingprinciples;c)Evaluatedtheeffectivenessoftheregistrant'sdisclosurecontrolsandproceduresandpresentedinthisreportourconclusionsabouttheeffectivenessofthedisclosurecontrolsandprocedures,asoftheendof theperiodcoveredbythisreportbasedonsuchevaluation;andd)Disclosedinthisreportanychangeintheregistrant'sinternalcontroloverfinancialreportingthatoccurredduringtheregistrant'smostrecentfiscalquarter(theregistrant'sfourthfiscalquarterinthecase ofanannualreport)thathasmateriallyaffected,orisreasonablylikelytomateriallyaffect,theregistrant'sinternalcontroloverfinancialreporting;and5.Theregistrant'sothercertifyingofficerandIhavedisclosed,basedonourmostrecentevaluationofinternalcontroloverfinancialreporting,totheregistrant'sauditorsandtheauditcommitteeoftheregistrant'sboardofdirectors(orpersonsperformingtheequivalentfunctions):a)Allsignificantdeficienciesandmaterialweaknessesinthedesignoroperationofinternalcontroloverfinancialreportingwhicharereasonablylikelytoadverselyaffecttheregistrant'sabilitytorecord,process,summarizeandreportfinancialinformation;andb)Anyfraud,whetherornotmaterial,thatinvolvesmanagementorotheremployeeswhohaveasignificantroleintheregistrant'sinternalcontroloverfinancialreporting.Date:February26,2016/s/RichardJ.MarkRichardJ.MarkChairmanandPresident (PrincipalExecutiveOfficer)

Exhibit31.6RULE13a-14(a)/15d-14(a)CERTIFICATIONOFPRINCIPALFINANCIALOFFICEROFAMERENILLINOISCOMPANY(requiredbySection302oftheSarbanes-OxleyActof2002)I,MartinJ.Lyons,Jr.,certifythat:1.IhavereviewedthisreportonForm10-KforthefiscalyearendedDecember31,2015,ofAmerenIllinoisCompany; 2.Basedonmyknowledge,thisreportdoesnotcontainanyuntruestatementofamaterialfactoromittostateamaterialfactnecessarytomakethestatementsmade,inlightofthecircumstancesunderwhichsuchstatementsweremade,notmisleadingwithrespecttotheperiodcoveredbythisreport;3.Basedonmyknowledge,thefinancialstatements,andotherfinancialinformationincludedinthisreport,fairlypresentinallmaterialrespectsthefinancialcondition,resultsofoperationsandcashflowsoftheregistrantasof,andfor,the periodspresentedinthisreport;4.Theregistrant'sothercertifyingofficerandIareresponsibleforestablishingandmaintainingdisclosurecontrolsandprocedures(asdefinedinExchangeActRules13a-15(e)and15d-15(e))andinternalcontroloverfinancialreporting(as definedinExchangeActRules13a-15(f)and15d-15(f))fortheregistrantandhave:a)Designedsuchdisclosurecontrolsandprocedures,orcausedsuchdisclosurecontrolsandprocedurestobedesignedunderoursupervision,toensurethatmaterialinformationrelatingtotheregistrant,includingitsconsolidatedsubsidiaries,ismadeknowntousbyotherswithinthoseentities,particularlyduringthe periodinwhichthisreportisbeingprepared;b)Designedsuchinternalcontroloverfinancialreporting,orcausedsuchinternalcontroloverfinancialreportingtobedesignedunderoursupervision,toprovidereasonableassuranceregardingthereliability offinancialreportingandthepreparationoffinancialstatementsforexternalpurposesinaccordancewith generallyacceptedaccountingprinciples;c)Evaluatedtheeffectivenessoftheregistrant'sdisclosurecontrolsandproceduresandpresentedinthisreportourconclusionsabouttheeffectivenessofthedisclosurecontrolsandprocedures,asoftheendof theperiodcoveredbythisreportbasedonsuchevaluation;andd)Disclosedinthisreportanychangeintheregistrant'sinternalcontroloverfinancialreportingthatoccurredduringtheregistrant'smostrecentfiscalquarter(theregistrant'sfourthfiscalquarterinthecase ofanannualreport)thathasmateriallyaffected,orisreasonablylikelytomateriallyaffect,theregistrant'sinternalcontroloverfinancialreporting;and5.Theregistrant'sothercertifyingofficerandIhavedisclosed,basedonourmostrecentevaluationofinternalcontroloverfinancialreporting,totheregistrant'sauditorsandtheauditcommitteeoftheregistrant'sboardofdirectors(orpersonsperformingtheequivalentfunctions):a)Allsignificantdeficienciesandmaterialweaknessesinthedesignoroperationofinternalcontroloverfinancialreportingwhicharereasonablylikelytoadverselyaffecttheregistrant'sabilitytorecord,process,summarizeandreportfinancialinformation;andb)Anyfraud,whetherornotmaterial,thatinvolvesmanagementorotheremployeeswhohaveasignificantroleintheregistrant'sinternalcontroloverfinancialreporting.Date:February26,2016/s/MartinJ.Lyons,Jr.MartinJ.Lyons,Jr.ExecutiveVicePresidentandChiefFinancialOfficer (PrincipalFinancialOfficer)

Exhibit32.1SECTION1350CERTIFICATIONOFAMERENCORPORATION(requiredbySection906oftheSarbanes-OxleyActof2002)InconnectionwiththereportonForm10-KforthefiscalyearendedDecember31,2015,ofAmerenCorporation(the"Registrant")asfiledbytheRegistrantwiththeSecuritiesandExchangeCommissiononthedatehereof(the"Form10-K"),eachundersignedofficeroftheRegistrantdoesherebycertify,pursuantto18U.S.C.§1350,asadoptedpursuantto§906of theSarbanes-OxleyActof2002,that:(1)TheForm10-KfullycomplieswiththerequirementsofSection13(a)or15(d)oftheSecuritiesExchangeActof1934(15U.S.C.78mor78o(d));and(2)TheinformationcontainedintheForm10-Kfairlypresents,inallmaterialrespects,thefinancialconditionandresultsofoperationsoftheRegistrant.Date:February26,2016/s/WarnerL.BaxterWarnerL.BaxterChairman,PresidentandChiefExecutiveOfficer (PrincipalExecutiveOfficer)/s/MartinJ.Lyons,Jr.MartinJ.Lyons,Jr.ExecutiveVicePresidentandChiefFinancialOfficer (PrincipalFinancialOfficer)

Exhibit32.2SECTION1350CERTIFICATIONOFUNIONELECTRICCOMPANY(requiredbySection906oftheSarbanes-OxleyActof2002)InconnectionwiththereportonForm10-KforthefiscalyearendedDecember31,2015,ofUnionElectricCompany(the"Registrant")asfiledbytheRegistrantwiththeSecuritiesandExchangeCommissiononthedatehereof(the"Form10-K"),eachundersignedofficeroftheRegistrantdoesherebycertify,pursuantto18U.S.C.§1350,asadoptedpursuantto§906of theSarbanes-OxleyActof2002,that:(1)TheForm10-KfullycomplieswiththerequirementsofSection13(a)or15(d)oftheSecuritiesExchangeActof1934(15U.S.C.78mor78o(d));and(2)TheinformationcontainedintheForm10-Kfairlypresents,inallmaterialrespects,thefinancialconditionandresultsofoperationsoftheRegistrant.Date:February26,2016/s/MichaelL.MoehnMichaelL.MoehnChairmanandPresident (PrincipalExecutiveOfficer)/s/MartinJ.Lyons,Jr.MartinJ.Lyons,Jr.ExecutiveVicePresidentandChiefFinancialOfficer (PrincipalFinancialOfficer)

Exhibit32.3SECTION1350CERTIFICATIONOFAMERENILLINOISCOMPANY(requiredbySection906oftheSarbanes-OxleyActof2002)InconnectionwiththereportonForm10-KforthefiscalyearendedDecember31,2015,ofAmerenIllinoisCompany(the"Registrant")asfiledbytheRegistrantwiththeSecuritiesandExchangeCommissiononthedatehereof(the"Form10-K"),eachundersignedofficeroftheRegistrantdoesherebycertify,pursuantto18U.S.C.§1350,asadopted pursuantto§906oftheSarbanes-OxleyActof2002,that:(1)TheForm10-KfullycomplieswiththerequirementsofSection13(a)or15(d)oftheSecuritiesExchangeActof1934(15U.S.C.78mor78o(d));and(2)TheinformationcontainedintheForm10-Kfairlypresents,inallmaterialrespects,thefinancialconditionandresultsofoperationsoftheRegistrant.Date:February26,2016/s/RichardJ.MarkRichardJ.MarkChairmanandPresident (PrincipalExecutiveOfficer)/s/MartinJ.Lyons,Jr.MartinJ.Lyons,Jr.ExecutiveVicePresidentandChiefFinancialOfficer (PrincipalFinancialOfficer) nancial highlights Ameren Consolidated In millions, except per share amounts and as notedYears ended Dec. 31 Results of Operations Operating revenues$6,098$6,053$5,838 Operating expenses$4,839$4,799$4,654 Operating income$1,259$1,254$1,184 Net income attributable to common shareholders from continuing operations

$579$587$512 Common Stock Data Continuing operations earnings per diluted share$2.38$2.40$2.10 Dividends per common share$1.655$1.61$1.60 Dividend yield (year-end) 3.9%3.6%4.4%Market price per common share (year-end closing)$43.23$46.13$36.16 Shares outstanding

- basic (weighted average)242.6 242.6 242.6Total market value of common shares (year-end)

$10,488$11,191$8,772 Book value per common share$28.63$27.67$26.97 Balance Sheet Data Property and plant, net$18,799$17,424$16,205Total assets$23,640$22,289$20,907 Long-term debt obligations, excluding current maturities

$6,880$6,085$5,475 Capitalization Ratios Common equity 48.3%48.8%50.2%Preferred stock 1.0%1.0%1.1%Debt, net of cash 50.7%50.2%48.7%Operating Data (Continuing)

Electric sales (kilowatt-hours) 79,092 79,955 80,003 Natural gas sales (decatherms in thousands) 182,927 202,810 195,266 Generation output (kilowatt-hours) 42,424 43,474 43,213 Electric customers 2.4 2.4 2.4 Natural gas customers 0.9 0.9 0.9 2015 2014 2013 GAAP to Core Earnings Reconciliation GAAP earnings per diluted share$2.59$2.40$1.18 Exclude results from discontinued operations (0.21)-0.92 Exclude provision for discontinuing pursuit of a license for a second nuclear unit at the Callaway Energy Center (included in continuing operations) 0.18--Core earnings per diluted share$2.56$2.40$2.10 COMMON STOCK AND DIVIDEND INFORMATIONAmeren's common stock is listed on the New York Stock Exchange (ticker symbol: AEE). Ameren began trading on Jan. 2, 1998, following the merger of Union Electric Company and CIPSCO Inc. on Dec. 31, 1997. Ameren common shareholders of record totaled 52,277 on Jan. 29, 2016. The following table provides the price ranges, closing prices and dividends declared per Ameren common share for each quarter of 2015 and 2014.ANNUAL MEETING The annual meeting of Ameren Corporation shareholders will convene at 10:30 a.m. (CDT) Thursday, April 28, 2016, at the Peoria Civic Center, 201 SW Jefferson Avenue, Peoria, Illinois 61602. The annual shareholder meetings of Ameren Illinois Company and Union Electric Company will be held at the same time.DRPLUS Any person of legal age or entity, whether or not an Ameren shareholder, is eligible to participate in DRPlus, Ameren's dividend reinvestment and stock purchase plan.Participants may:ł Make cash investments by check or automatic direct debit from their bank accounts to purchase Ameren common stock, up to a maximum of $360,000 annually;ł Reinvest their dividends in Ameren common stock (the minimum dividend reinvestment requirement is 10% per share); and ł Place Ameren common stock certificates in safekeeping and receive regular account statements.

For more information about DRPlus, you may obtain a prospectus from Ameren's Investor Services representatives.

DIRECT DEPOSIT OF DIVIDENDS All registered Ameren common and Ameren Illinois Company and Union Electric Company preferred shareholders may have their cash dividends automatically deposited to their bank accounts.

This service gives shareholders immediate access to their dividend on the dividend payment date and eliminates the possibility of lost or stolen dividend checks.CORPORATE GOVERNANCE DOCUMENTS Ameren makes available, free of charge through its website (Ameren.com), the charters of the Board of Directors' Audit and Risk Committee, Finance Committee, Human Resources Committee, Nominating and Corporate Governance Committee and Nuclear Oversight and Environmental Committee.

Also available on Ameren's website are its corporate governance guidelines, policy regarding nominations of directors, policy regarding communications to the Board of Directors, policy and procedures with respect to related person transactions, code of business conduct (referred to as the "Principles of Business Conduct")

and code of ethics for principal executive and senior nancial ofcers. These documents are also available in print, free of charge upon written request, from the Ofce of the Secretary, Ameren Corporation, P.O. Box 66149, Mail Code 1370, St. Louis, Missouri 63166-6149.

Ameren also makes available, free of charge through its website, the company's annual reports on SEC Form 10-K, quarterly reports on SEC Form 10-Q and its current reports on SEC Form 8-K, including any chief executive ofcer and chief nancial ofcer certications required to be led with the Securities and Exchange Commission.

ONLINE STOCK ACCOUNT ACCESSAmeren's website (Ameren.com) allows registered shareholders to access their account information online. Shareholders may securely change their reinvestment options, view account summaries, receive DRPlus statements and more through the website. This is a free service.INVESTOR SERVICESAmeren's Investor Services representatives are available to help you each business day from 8 a.m. to 4 p.m. (Central Time). Please write or call: Ameren Services Company, Investor ServicesP.O. Box 66887 St. Louis, Missouri 63166-6887

314.554.3502 or 800.255.2237

invest@ameren.com TRANSFER AGENT, REGISTRAR AND PAYING AGENT The Transfer Agent, Registrar and Paying Agent for Ameren common stock and Ameren Illinois Company and Union Electric Company preferred stock is Ameren Services Company.investor information Ameren Corporation One Ameren Plaza l 1901 Chouteau Avenue l St. Louis, Missouri 63103 l 314.621.3222 AEE 2015 Quarter Ended March 31 June 30 Sept.30 Dec.31 High$46.81$43.00$43.85$44.71 Low$40.51$37.26$37.55$41.33 Close$42.20$37.68$42.27$43.23 Dividends Declared 41 ¢41 ¢41 ¢42.5 ¢AEE 2014 Quarter Ended March 31 June 30 Sept.30 Dec.31 High$42.24$41.92$40.96$48.14 Low$35.22 $37.67 $36.65$38.25 Close$41.20$40.88$38.33$46.13 Dividends Declared 40 ¢40 ¢40 ¢41 ¢SI1506_AmerenAR_COVER.indd D-F SI1506_AmerenAR_COVER.indd D-F 3/1/16 9:42 AM 3/1/16 9:42 AM AMEREN l 2015 Annual Report and Form 10-K2015 ANNUAL REPORTP.O. Box 66149 l St. Louis, Missouri 63166-6149 AMEREN.COM On the cover: This portion of the $1.4 billion Illinois Rivers Transmission Project near Champaign, Illinois, is expected to enter service in the fall of 2016. On the back cover: The natural gas storage eld in Lincoln, Illinois, ensures that natural gas is safely and reliably delivered to customers.

SI1506_AmerenAR_COVER.indd A-C SI1506_AmerenAR_COVER.indd A-C 2/26/16 9:01 AM 2/26/16 9:01 AM