Shareholder Vote

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549   FORM  8-K   CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934   Date of report (Date of earliest event reported): May 14, 2026   Commission File Number   Exact Name of Registrant as Specified in Charter; State of Incorporation; Address and Telephone Number   IRS Employer Identification Number   1-14756     Ameren Corporation ( Missouri Corporation) 1901 Chouteau Avenue St. Louis , Missouri 63103 ( 314 ) 621-3222       43-1723446   1-2967   Union Electric Company ( Missouri Corporation) 1901 Chouteau Avenue St. Louis , Missouri 63103 ( 314 ) 621-3222   43-0559760   1-3672   Ameren Illinois Company ( Illinois Corporation) 10 Richard Mark Way Collinsville , Illinois 62234 ( 618 ) 343-8150   37-0211380   Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrants under any of the following provisions: ¨ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ¨ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ¨ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ¨ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))   Securities registered pursuant to Section 12(b) of the Act:   Title of each class   Trading Symbol(s)   Name of each exchange on which registered Common Stock, $0.01 par value per share   AEE   New York Stock Exchange   Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).     Emerging Growth Company   Ameren Corporation ¨   Union Electric Company ¨   Ameren Illinois Company ¨     If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.   Ameren Corporation ¨   Union Electric Company ¨   Ameren Illinois Company ¨       Co-Registrant CIK 0000100826 Co-Registrant Amendment Flag false Co-Registrant Form Type 8-K Co-Registrant DocumentperiodEndDate 2026-05-14 Co-Registrant Written Commuunications false Co-Registrant Solicitating Materials false Co-Registrant PreCommencement Tender Offer false Co-Registrant PreCommencement Tender Offer false Co-Registrant Entity PreCommencement Issuer Tender Offer false Co-Registrant CIK 0000018654 Co-Registrant Amendment Flag false Co-Registrant Form Type 8-K Co-Registrant DocumentperiodEndDate 2026-05-14 Co-Registrant Written Commuunications false Co-Registrant Solicitating Materials false Co-Registrant PreCommencement Tender Offer false Co-Registrant PreCommencement Tender Offer false Co-Registrant Entity PreCommencement Issuer Tender Offer false     ITEM 5.07 Submission of Matters to a Vote of Security Holders.   At the annual meeting of shareholders of each of Ameren Corporation (“Ameren”), Union Electric Company, doing business as Ameren Missouri (“Ameren Missouri”), and Ameren Illinois Company, doing business as Ameren Illinois (“Ameren Illinois”), held on May 14, 2026 (“Annual Meeting”), the matters listed below were submitted to a vote of each company’s respective shareholders.   Ameren   Item (1): Election of Directors   The following individuals (comprising Ameren’s full Board of Directors) were elected:   Name   Votes For     Votes Against     Abstentions     Broker Non-Votes   Cynthia J. Brinkley     211,811,213       6,224,999       509,328       24,519,860   Ward H. Dickson     215,897,083       2,148,175       500,282       24,519,860   Jamie L. Engstrom     216,191,429       1,854,870       499,241       24,519,860   Ellen M. Fitzsimmons     210,790,937       7,306,393       448,210       24,519,860   Rafael Flores     212,466,281       5,556,585       522,674       24,519,860   Richard J. Harshman     211,458,704       6,517,496       569,340       24,519,860   Craig S. Ivey     213,177,307       4,882,181       486,052       24,519,860   Steven H. Lipstein     203,929,254       14,096,981       519,305       24,519,860   Martin J. Lyons, Jr.     211,634,204       6,520,326       391,010       24,519,860   Leo S. Mackay, Jr.     215,933,079       2,121,870       490,591       24,519,860   Timothy S. Rausch     215,974,758       1,948,882       621,900       24,519,860   Steven O. Vondran     215,831,571       2,064,068       649,901       24,519,860     Item (2): Advisory Approval of Executive Compensation   Vote Result   Votes For     Votes Against     Abstentions     Broker Non-Votes   Approved     208,210,735       9,383,298       951,507       24,519,860     Item (3): Ratification of the Appointment of PricewaterhouseCoopers LLP as Independent Registered Public Accounting Firm for the Fiscal Year Ending December 31, 2026   Vote Result   Votes For     Votes Against     Abstentions     Broker Non-Votes   Approved     232,732,466       9,840,141       492,793       —     Ameren Missouri   Item (1): Election of Directors   At Ameren Missouri’s Annual Meeting, the following individuals (comprising Ameren Missouri’s full Board of Directors) were elected: Michael L. Moehn, Ajay K. Arora, David M. Feinberg, Ryan J. Martin, and Leonard P. Singh. Each individual received 102,123,834 votes for election and no withheld votes, abstentions or broker non-votes.   Ameren Illinois   Item (1): Election of Directors   At Ameren Illinois’ Annual Meeting, the following individuals (comprising Ameren Illinois’ full Board of Directors) were elected: Patrick E. Smith Sr., David M. Feinberg, Michael L. Moehn, Theresa A. Shaw, and Leonard P. Singh. Each individual received 25,452,373 votes for election and no withheld votes, abstentions or broker non-votes.       This combined Form 8-K is being filed separately by Ameren Corporation, Union Electric Company and Ameren Illinois Company (each a “registrant”). Information contained herein relating to any individual registrant has been filed by such registrant on its own behalf. No registrant makes any representation as to information relating to any other registrant.       SIGNATURES   Pursuant to the requirements of the Securities Exchange Act of 1934, each registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized. The signature for each undersigned company shall be deemed to relate only to matters having reference to such company or its subsidiaries.     AMEREN CORPORATION   (Registrant)         By:  /s/ David M. Feinberg   Name: David M. Feinberg   Title: Executive Vice President, General Counsel and Secretary       UNION ELECTRIC COMPANY   (Registrant)         By: /s/ David M. Feinberg   Name: David M. Feinberg   Title: Executive Vice President, General Counsel and Secretary       AMEREN ILLINOIS COMPANY   (Registrant)         By: /s/ David M. Feinberg   Name: David M. Feinberg   Title: Executive Vice President, General Counsel and Secretary   Date: May 18, 2026