15 unchanged sentences
• the discount rate applicable to AROs, goodwill, and defined pension and postretirement benefit plans.
−Removed: We manage our interest rate exposure by controlling the amount of debt instruments within our total capitalization portfolio, by monitoring the effects of market changes on interest rates, and by entering into interest rate swaps to hedge a portion of our interest rate risk on cash flows related to forecasted debt issuances.
+Added: We manage our interest rate exposure by controlling the amount of debt instruments within our total capitalization portfolio, by monitoring the effects of market changes on interest rates, and by entering into interest rate swaps to hedge a portion of our interest rate risk on cash flows related to certain forecasted debt issuances.
For defined pension and postretirement benefit plans, we control the duration and the portfolio mix of our plan assets.
1 unchanged sentence
The estimated increase in our annual interest expense and decrease in net income if interest rates were to increase by 100 basis points on variable-rate debt outstanding at December 31, 2025 is immaterial.
−Removed: The allowed ROE under Ameren Illinois’ electric energy-efficiency investments formula ratemaking recovery mechanisms is based on the annual average of the monthly yields of the 30-year United States Treasury bonds plus 580 basis points.
+Added: Through 2026, the allowed ROE under Ameren Illinois’ electric energy-efficiency investments formula ratemaking recovery mechanisms is based on the annual average of the monthly yields of the 30-year United States Treasury bonds plus 580 basis points.
Therefore, Ameren Illinois’ annual ROE for its electric energy-efficiency investments is directly correlated to the yields on such bonds, which are outside of Ameren Illinois’ control.
11 unchanged sentences
At the option of an alternative retail electric supplier, Ameren Illinois may be required to purchase the supplier’s receivables relating to Ameren Illinois’ distribution customers who elected to receive power supply from the alternative retail electric supplier.
−Removed: When that option is selected, Ameren Illinois produces consolidated bills for the applicable retail customers to reflect charges for electric distribution and purchased receivables from the alternative retail electric suppler.
+Added: When that option is selected, Ameren Illinois produces consolidated bills for the applicable retail customers to reflect charges for electric distribution and purchased receivables from the alternative retail electric supplier.
As of December 31, 2025, Ameren Illinois’ balance of purchased accounts receivable associated with the utility consolidated billing and purchase of receivables services was $47 million.
30 unchanged sentences
Ameren Missouri’s and Ameren Illinois’ strategy is designed to reduce the effect of market fluctuations for their customers.
+Added: Current industry projections reflect the potential for significant growth in energy demand over the next decade, primarily arising from data centers and further augmented by onshoring and electrification of manufacturing and an increase in transportation electrification.
+Added: This projected growth could create volatility for the prices of purchased power and capacity.
The effects of price volatility cannot be eliminated.
6 unchanged sentences
Ameren Illinois purchases energy and capacity through bilateral contracts resulting from IPA procurement events, with any remaining needs procured through the MISO marketplace.
−Removed: Ameren Illinois has purchased approximately 14% of its summer 2025, 9% of its fall 2025, none of its winter 2025/26 and 2% of its spring 2026 capacity needs bilaterally, however, this percentage beyond May 2026 will be dependent on the results of future IPA procurement events.
+Added: Ameren Illinois has purchased approximately 55% of its summer 2026, 46% of its fall 2026, 40% of
+Added: its winter 2026/27 and 61% of its spring 2027 capacity needs bilaterally, however, this percentage beyond May 2027 will be dependent on the results of future IPA procurement events.
Daily energy balancing is also handled through the MISO marketplace.
−Removed: Through the IPA's
−Removed: development and filing of the 2025 Electricity Procurement Plan, the ICC has approved the plan's proposal for multiple IPA procurement events over the following year.
+Added: Through the IPA's development and filing of the 2026 Electricity Procurement Plan, the ICC has approved the plan's proposal for multiple IPA procurement events over the following year.
These events will procure portions of Ameren Illinois' energy and capacity forecasted requirements for forward delivery years through May 2029.
Ameren Illinois has also entered into ICC-approved contracts for zero emission credits through May 2027 and for renewable energy credits with various terms, including contracts with 20-year terms ending 2032, and contracts entered into beginning in 2018 through 2025 with 15- to 20-year terms.
+Added: Pursuant to Illinois law, Ameren Illinois is required to enter into these contracts to comply with Illinois’ renewable energy and zero emission standards.
+Added: These contracts, with the exception of certain contracts entered into in 2010, do not serve to meet Ameren Illinois’ energy and capacity needs.
Ameren Illinois does not generate earnings based on the resale of power or purchase of zero emission credits or renewable energy credits but rather on the delivery of the energy.
25 unchanged sentences
Our exposure to commodity price risk for construction and maintenance activities is related to changes in market prices for metal commodities and to labor availability.
−Removed: Also see Note 14 – Commitments and Contingencies under Part II, Item 8, of this report for additional information.
Commodity Supplier Risk
7 unchanged sentences
Compared sentence by sentence after normalising whitespace, quotation marks, case and digits, so re-formatting and restated figures do not read as changed language. Wording changes appear as one removal and one addition. The current filing and the prior one are authoritative.