Company Update

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): November 16, 2023       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 1-3672   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 ¨   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 ¨   Ameren Illinois Company ¨       Co-Registrant CIK 0000018654 Co-Registrant Amendment Flag false Co-Registrant Form Type 8-K Co-Registrant DocumentperiodEndDate 2023-11-16 Co-Registrant Written Commuunications false Co-Registrant Solicitating Materials false Co-Registrant PreCommencement Tender Offer false Co-Registrant Entity PreCommencement Issuer Tender Offer false         ITEM 8.01 Other Events.   Reference is made to Note 2 – Rate and Regulatory Matters to the financial statements under Part I, Item 1. Financial Statements and to Overview and Outlook under Part I, Item 2. Management's Discussion and Analysis of Financial Condition and Results of Operations, each in the Quarterly Report on Form 10-Q for the quarter ended September 30, 2023; and to Note 2 - Rate and Regulatory Matters to the financial statements under Part II, Item 8. Financial Statements and Supplementary Data and to Overview and Outlook under Part II, Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations, each in the Annual Report on Form 10-K for the year ended December 31, 2022, of registrants Ameren Corporation and Ameren Illinois Company (“Ameren Illinois”), for a discussion of Ameren Illinois' natural gas delivery service regulatory rate review filed with the Illinois Commerce Commission (“ICC”) in January 2023.   On November 16, 2023, the ICC issued an order approving a $112 million annual base rate increase for Ameren Illinois' natural gas delivery service, which included $77 million that would have otherwise been recovered in 2024 under riders. The increase reflects a 9.44% allowed return on equity, a 50% common equity ratio, and a rate base of $2.85 billion. The order reflected a reduction of approximately $93 million of distribution and transmission capital investments included in Ameren Illinois' requested revenue increase, which used a 2024 future test year. Ameren Illinois is evaluating the potential implications of the order; however, the reduced level of capital investments is expected to have an immaterial effect on its 2023 results of operations, financial position and liquidity.   New rates reflecting the ICC order will become effective in late November 2023.   Ameren Illinois has not decided whether to seek rehearing of any aspect of the order or subsequently appeal any aspect of the order. The intervenor parties to this case may similarly seek rehearing or subsequently appeal any aspect of the order. Ameren Illinois cannot predict whether any such application for rehearing or appeal will be filed, or the outcome if so filed.        This combined Form 8-K is being filed separately by Ameren Corporation and Ameren Illinois (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/ Michael L. Moehn   Name: Michael L. Moehn   Title: Senior Executive Vice President and     Chief Financial Officer       AMEREN ILLINOIS COMPANY   (Registrant)       By: /s/ Leonard P. Singh   Name: Leonard P. Singh   Title: Chairman and President     Date: November 21, 2023