Ameren Rider MAP-P 2022 PUBLIC NOTICE | Legal announcements

PUBLIC NOTICE Notice of Proposed Rate Changes Electric Service Schedule Ill. CC No. 1 To the Electric Patrons of Ameren Illinois Company d/b/a Ameren Illinois: Ameren Illinois (or the Company) hereby notifies the public that on April 14, 2022, it filed with the Commerce Commission of Illinois (CCI or Commission) proposed changes to its rates and charges for electricity delivery services throughout its Illinois territory pursuant to its Rider MAP-P, performance-based rate, and updated its calculation of tariffs and charges according to the formula tariff tariff. The changes apply to Ameren Illinois Rate Zones I, II, and III, as further described below. The rate schedule changes are proposed to take effect with the January 2023 billing period – after the Commission issues its final order. The Board has up to 240 days to complete this proceeding and issue its final order. This filing complies with Illinois Public Laws 097-0616, 097-0646, and 098-0015 (the “Law”). These public laws also require the Corporation to spend $625 million in electrical system modernization investments over a 10-year period. This upgrade will benefit customers and create 450 new jobs in the program’s peak year. In addition, the Company is required by law to meet various performance measures intended to increase reliability, reduce outage times and provide better service to customers, or face financial penalties. Proposed Update to Formula Tariff Revenue Requirement Results in an Overall Annual Increase of $83.19 Million from Electricity Revenue Requirement Last Ordered by ICC in Docket #21 -0365. The proposed rates in this proceeding will reflect rate design changes, including rate uniformity between the same rate classes in different rate zones, with two exceptions approved in File No. 19-0877. Pole charges for DS-5 lighting customers in Rate Zone III and meter reassignment charges for certain DS-3 and DS-4 customers in Rate Zone I will remain independent per rate zone. For the DS-1 Residential Delivery Service classification, the proposed increase in Electricity Delivery Service Cost Recovery Revenue and Electricity Distribution Tax (EDT) is 7.5%. Rates for delivery service and EDT cost recovery are only a portion of the total bill for a customer currently taking bundled electrical service from Ameren Illinois or taking supply service from a third-party provider. . The following compares the Company’s proposal to the bundled bill (delivery service charge in effect today and purchased electricity charge in effect until May 2022) for residential customers: 1) For a residential customer using 5,000 kWh per year (or an average of 417 kWh per month), the effect of the Company’s proposed delivery service bill changes produces an average monthly increase of $1.80. 2) For a residential customer using 10,000 kWh annually (or an average of 833 kWh monthly), the effect of changes to the delivery service bill proposed by the Company produces an average monthly increase of $3.58. 3) For a residential customer using 18,000 kWh per year (or an average of 1,500 kWh per month), the effect of the changes to the delivery service bill proposed by the Company produces an average monthly increase of $5.36 . For non-residential customers, the proposed changes to electricity delivery service and EDT’s cost recovery revenues are as follows: – For DS-2, small general delivery service, increase of 8.6%; – For DS-2, (optional fee), small general delivery service, 10.5% increase; – For DS-3, general delivery service, increase of 10.9%; – For DS-4, large general delivery service, increase of 8.2%; – For DS-5, lighting service, increase of 12.4%; and – For DS-6, Temperature Sensitive Delivery Service, an increase of 12.3%. The Commission registered the case under number 22-0297. A copy of the proposed schedule change may be viewed at the offices of Ameren Illinois at 300 Liberty Street, Peoria, Illinois or online at Customers should be advised that the Board may modify or otherwise amend rates or conditions of service after hearings are held pursuant to 83 Ill. Adm. Code Part 200, and may increase or decrease individual rates in amounts other than those requested by Ameren Illinois. All parties interested in this matter may obtain information regarding this matter either directly from Ameren Illinois or by contacting the Chief Clerk of the Illinois Commerce Commission, 527 East Capitol Avenue, Springfield, Illinois 62706 AMEREN ILLINOIS COMPANY d/b/a Ameren Illinois By: Richard J. Mark, President and CEO 128988

Earnest L. Veasey