0001002910 2026-08-04 2026-08-04 0001002910 1 2026-08-04 2026-08-04 0001002910 2 2026-08-04 2026-08-04 0001002910 3 2026-08-04 2026-08-04 0001002910 4 2026-08-04 2026-08-04 0001002910 5 2026-08-04 2026-08-04 0001002910 6 2026-08-04 2026-08-04 0001002910 7 2026-08-04 2026-08-04 0001002910 8 2026-08-04 2026-08-04 0001002910 9 2026-08-04 2026-08-04 0001002910 10 2026-08-04 2026-08-04 0001002910 11 2026-08-04 2026-08-04 0001002910 12 2026-08-04 2026-08-04 0001002910 13 2026-08-04 2026-08-04 0001002910 14 2026-08-04 2026-08-04 0001002910 15 2026-08-04 2026-08-04 iso4217:USD pure shares S-3 S-3ASR EX-FILING FEES 0001002910 AMEREN CORP N/A N/A S-3 AMEREN CORP false Debt Ameren Corporation Senior Debt Securities true 0.0001381 false Debt Ameren Corporation Subordinated Debt Securities true 0.0001381 false Equity Ameren Corporation Common Stock, $.01 par value true 0.0001381 false Equity Ameren Corporation Preferred Stock true 0.0001381 false Other Ameren Corporation Stock Purchase Contracts true 0.0001381 false Other Ameren Corporation Stock Purchase Units true 0.0001381 false Debt Union Electric Company Senior Secured Debt Securities true 0.0001381 false Debt Union Electric Company First Mortgage Bonds true 0.0001381 false Debt Union Electric Company Senior Unsecured Debt Securities true 0.0001381 false Equity Union Electric Company Preferred Stock true 0.0001381 false Debt Ameren Illinois Company Senior Secured Debt Securities true 0.0001381 false Debt Ameren Illinois Company First Mortgage Bonds true 0.0001381 false Debt Ameren Illinois Company Senior Unsecured Debt Securities true 0.0001381 false Equity Ameren Illinois Company Preferred Stock true 0.0001381 Equity Ameren Corporation Common Stock, $.01 par value true 266700000 266700000.00 S-3 333-274977 2023-10-13 40831.77 266700000.00 0.00 0.00 0.00 0.00 In addition to the shares of Ameren Corporation Common Stock, $.01 par value, having a gross sales price of up to $266,700,000 described in Note (15), an additional unspecified aggregate initial offering amount or number of the securities of each identified class is being registered as may from time to time be offered by Ameren Corporation, Union Electric Company and Ameren Illinois Company or sold by selling securityholders, if and as allowed, at unspecified prices, along with an indeterminate amount or number of securities that may be issued upon exercise, settlement, exchange or conversion of securities offered hereunder. In accordance with Rules 456(b) and 457(r) under the Securities Act of 1933, as amended (the "Securities Act"), the registrants are deferring payment of the registration fee in connection with such additional securities offered hereby, and the registrants will pay "pay as you go registration fees" in accordance with Rules 456(b) and 457(r) under the Securities Act with respect to those additional securities. See Offering Note 1. See Offering Note 1. See Offering Note 1. See Offering Note 1. See Offering Note 1. See Offering Note 1. See Offering Note 1. See Offering Note 1. See Offering Note 1. See Offering Note 1. See Offering Note 1. See Offering Note 1. See Offering Note 1. Pursuant to Rule 415(a)(6) under the Securities Act, there is included on this registration statement shares of Ameren Corporation Common Stock, $.01 par value, having a gross sales price of up to $266,700,000 that were previously registered for offer and sale, but not sold, in connection with Ameren Corporation's Equity Distribution Sales Agreement, dated May 12, 2021, as amended and supplemented, including by the First Amendment to Equity Distribution Sales Agreement, dated August 7, 2025 (as so amended and supplemented, the "Sales Agreement"), pursuant to a Rule 424(b)(5) filing made with the Securities and Exchange Commission (the "Commission") on August 7, 2025 under Registration Statement No. 333-274977 filed with the Commission on October 13, 2023 (the "Prior Registration Statement"), and for which a filing fee of $40,831.77 with respect to such unsold shares was paid in connection therewith. Pursuant to Rule 415(a)(6) under the Securities Act, the filing fee related to such unsold shares will continue to be applied to the offer and sale of such unsold shares pursuant to the Sales Agreement. Pursuant to Rule 415(a)(6) under the Securities Act, the offering of shares under the Prior Registration Statement will be deemed terminated as of the date of effectiveness of this registration statement.