AEE: Ameren Missouri Files 2026 IRP

Ameren Missouri’s 2026 IRP formally sets the company’s planning horizon through 2045, establishing the framework for resource additions, retirements and grid investments over the next two decades. The IRP is a planning document submitted to regulators that guides how Ameren Missouri expects to meet customer demand while responding to policy, reliability and cost pressures. The filing builds on the company’s existing asset base and recent project activity. Ameren’s generation mix includes coal capacity of 3,344 MW and nuclear capacity of 1,196 MW at Callaway, supplemented by natural gas, hydro, wind and solar resources. Recent renewable additions noted in company disclosures include Split Rail Solar and Bowling Green Solar coming into service in 2026.

The IRP is likely to reinforce the company’s three strategic pillars: continued rate-regulated infrastructure investment, active engagement with regulators to secure recovery and incentives, and operational optimization to support reliability. Public filings describe implied annual capex in the multibillion-dollar range ($3–4B) and specific programs such as a Smart Energy Plan exceeding $1B through 2030 and awarded transmission investment in MISO Tranche 1 of $1.8B. For investors, the IRP frames future rate-base growth and regulatory filings that drive allowed returns. Existing recovery mechanisms and regulatory outcomes remain material: for example, MoPSC staff recommended a $384 million increase at a 9.74% ROE in Ameren Missouri’s pending electric rate case, while Ameren Transmission has an approved ROE of 10.48% under its cost recovery framework.

The IRP is being submitted amid active regulatory and legal matters that shape the company’s planning and cash flows. Key items in company disclosures include an outstanding MoPSC electric rate case (prudency and rate design issues pending), appeals and rehearing activity related to Ameren Illinois distribution rate orders, and environmental oversight tied to coal retirements and CCR rules. Rush Island’s approved retirement and related prudency reviews remain part of that regulatory history. Financial and operational risks flagged in filings include near-term debt maturities (reported debt maturities of $973 million in 2026), coverage covenant metrics (e.g., Ameren Missouri reported interest coverage of 3.2x versus a 2.0x covenant threshold), and exposure to commodity and fuel supply dynamics despite fuel adjustment and purchased gas adjustment mechanisms that mitigate roughly 95% of commodity volatility.

The 2026 IRP arrives after a series of financing and capital actions in 2026 that provide context for funding the transition and rate-base growth. Recent corporate financings include the sale of $900 million of junior subordinated notes due 2057 (2026-09-18), a $400 million 5.50% bond issuance by a subsidiary (2026-08-24), and an increase to the equity distribution program limit by $2 billion (2026-08-04). These actions, together with ongoing capex guidance and approved transmission awards, inform how Ameren may fund projects outlined in the IRP.