AMEREN CORP

Ameren Missouri owns energy centers that rely on a diverse fuel portfolio, including coal, nuclear, and natural gas, as well as renewable sources of generation. Both of Ameren Missouri’s coal-fired energy centers were constructed prior to 1978. As of December 31, 2025, Ameren Missouri’s coal-fired energy centers represented 5% and 11% of Ameren’s and Ameren Missouri’s rate base, respectively. The Callaway Energy Center began operation in 1984 and is currently licensed to operate until 2044. Ameren Illinois operates two solar generation facilities, which are two of three pilot solar projects Ameren Illinois is allowed to invest in under the CEJA. The third solar generation facility is planned to be placed in service before the end of 2026. See Item 2 – Properties under Part I of this report for information regarding our energy centers.

Coal

Ameren Missouri has an ongoing need for coal as fuel for generation, and pursues a price-hedging strategy consistent with this requirement. Ameren Missouri has agreements in place to purchase and transport coal to its energy centers. While Ameren Missouri has minimum purchase obligations associated with these agreements, the majority of these agreements are not associated with any specific coal-fired energy center. Ameren Missouri burned approximately 12.0 million tons of coal in 2025. For information regarding the percentages of Ameren Missouri’s projected required supply of coal and coal transportation that are price-hedged through 2030, see Commodity Price Risk under Part II, Item 7A, of this report.

Approximately 96% of Ameren Missouri’s coal is purchased from the Powder River Basin in Wyoming, which has a limited number of suppliers. The remaining coal is typically purchased from the Illinois Basin. Targeted coal inventory levels may be adjusted because of generation levels or uncertainties of supply due to delays in coal deliveries, equipment breakdowns, and other factors. Deliveries from the Powder River Basin have occasionally been restricted because of rail congestion, staffing and equipment issues, infrastructure maintenance, derailments, weather, and supplier financial hardship. Delays and disruptions in coal deliveries could cause Ameren Missouri to pursue a strategy that could include reducing off-system sales of power during low-earning periods, buying higher-cost fuels to generate required electricity, and purchasing power from other sources.

Nuclear

The production of nuclear fuel involves the mining and milling of uranium ore to produce uranium concentrates, the conversion of uranium concentrates to uranium hexafluoride gas, the enrichment of that gas, the conversion of the enriched uranium hexafluoride gas into uranium dioxide fuel pellets, and the fabrication into fuel assemblies. Ameren Missouri has entered into uranium, uranium conversion, uranium enrichment, and fabrication contracts to procure the fuel supply for its Callaway Energy Center.

The Callaway Energy Center requires refueling at 18-month intervals. The last refueling was completed in July 2025. The next refueling is scheduled for the fall of 2026. Ameren Missouri has inventories and supply contracts sufficient to meet all of its uranium (concentrate and hexafluoride), conversion, enrichment, and fabrication requirements at least through the fall 2029 refueling.

Renewable

Ameren Missouri operates several renewable energy centers, which includes hydroelectric, wind, methane gas, and solar energy centers. The High Prairie and Atchison energy centers are wind generation facilities. The Huck Finn, Boomtown, Cass County, and Vandalia energy centers are solar generation facilities. In February 2026, Ameren Missouri acquired the Split Rail Solar Project, which is expected to be placed in service in the second quarter of 2026. The Osage and Keokuk energy centers generate electricity using hydroelectric dams located on the Lake of the Ozarks and the Mississippi River, respectively. The Taum Sauk Energy Center is a pumped-storage hydroelectric facility that generates electricity by releasing water from an upper reservoir through turbines into a lower reservoir during periods of high demand, then pumping the water back up during off-peak hours for reuse. The Maryland Heights Energy Center generates electricity by burning methane gas collected from a landfill. For additional information regarding newly constructed or acquired energy centers, see Note 2 – Rate and Regulatory Matters under Part II, Item 8, of this report.