AEE · 10-Q · 2026Q3 · Full report

Transmission Rate Requirements

AMEREN CORP · 2026-11-06 · Importance 42 · Surprise 40 · No source text

Ameren Illinois and ATXI’s 2027 electric-transmission revenue requirements are $749 million and $319 million, respectively, increases of $64 million and $53 million from 2026, primarily due to higher expected rate base. A pending FERC proposal could eliminate their 50-basis-point RTO incentive adder prospectively and limit the incentive to three years for utilities joining an RTO. A 50-basis-point change in allowed ROE would affect annual net income by an estimated $19 million for Ameren and $14 million for Ameren Illinois, based on 2026 projected rate base.

Key facts

• Revenue requirements included in 2027 rates are $749 million for Ameren Illinois electric transmission and $319 million for ATXI electric transmission, increases of $64 million and $53 million, respectively, from 2026 rates.
• In August 2026, FERC approved transmission-rate incentives for two ATXI competitive projects, allowing construction work in progress into rate base and recovery of prudently incurred costs if projects are abandoned for reasons beyond ATXI’s control, subject to FERC approval.
• If the FERC proposal to limit the RTO incentive is adopted, Ameren Illinois and ATXI would prospectively lose eligibility for the 50-basis-point RTO incentive adder.
• Ameren Transmission’s electric revenues increased $26 million (11%) and $64 million (10%) in the three and nine months ended September 30, 2026, respectively; higher recoverable expenses contributed $17 million and $39 million, and return on higher rate base contributed $9 million and $25 million.
• Ameren Illinois Transmission’s revenues increased $20 million (11%) and $46 million (10%) in the three and nine months ended September 30, 2026, respectively; rate base used to calculate its revenue requirement increased 8%.
• The currently allowed transmission ROE is 10.48%, including a 50-basis-point incentive adder for RTO participation.
• A 50-basis-point change in FERC-allowed ROE would affect estimated annual net income by $19 million for Ameren and $14 million for Ameren Illinois, based on 2026 projected rate base.

Impact estimates