AEE: Other company developments

ITEM 8.01 Other Events. On June 29, 2026, Union Electric Company, doing business as Ameren Missouri (“Ameren Missouri”), a subsidiary of Ameren Corporation, sold $500 million principal amount of its 5.75% First Mortgage Bonds due 2056 (the “Bonds”). The Bonds were offered pursuant to a Registration Statement on Form S-3 (File No. 333-274977-02), which became effective on October 13, 2023, and a Prospectus Supplement dated June 15, 2026, to a Prospectus dated October 13, 2023. Ameren Missouri received net offering proceeds of approximately $492.2 million, before expenses, upon closing of the transaction. This Current Report on Form 8-K is being filed to report as exhibits certain documents in connection with the offering of the Bonds. ITEM 9.01 Financial Statements and Exhibits. (d) Exhibits Exhibit Number Title 1 Underwriting Agreement relating to the Bonds, dated June 15, 2026, between Ameren Missouri and the several underwriters named therein, for whom Fifth Third Securities, Inc., Mizuho Securities USA LLC, TD Securities (USA) LLC, Truist Securities, Inc. and U.S. Bancorp Investments, Inc. are acting as representatives. 4.1* Indenture of Mortgage and Deed of Trust, dated June 15, 1937, from Ameren Missouri to The Bank of New York Mellon, as successor trustee, as amended May 1, 1941, and Second Supplemental Indenture dated May 1, 1941 (Exhibit B-1, File No. 2-4940). 4.2 Supplemental Indenture, dated June 1, 2026, by and between Ameren Missouri and The Bank of New York Mellon, as successor trustee, relating to the 5.75% First Mortgage Bonds due 2056. 5.1 Opinion of David M. Feinberg, Esq., Executive Vice President, General Counsel and Secretary of Ameren Missouri, regarding the legality of the Bonds (including consent). 5.2 Opinion of Morgan, Lewis & Bockius LLP regard