Financial Analysis

COMMITMENTS AND CONTINGENCIES We are involved in legal, tax, and regulatory proceedings before various courts, regulatory commissions, authorities, and governmental agencies with respect to matters that arise in the ordinary course of business, some of which involve substantial amounts of money. We believe that the final disposition of these proceedings, except as otherwise disclosed in the notes to our financial statements, will not have a material adverse effect on our results of operations, financial position, or liquidity. See also Note 1 Summary of Significant Accounting Policies, Note 2 Rate and Regulatory Matters, Note 9 Callaway Energy Center, Note 13 Related-party Transactions, and Note 15 Supplemental Information in this report. Environmental Matters Our electric generation, transmission, and distribution and natural gas distribution and storage operations must comply with a variety of statutes and regulations relating to the protection of the environment and human health and safety, including permitting programs implemented by federal, state, and local authorities. Such environmental laws regulate air emissions; protect water bodies; regulate the handling and disposal of hazardous substances and waste materials; establish siting and land use requirements; and protect against ecological impacts. Complex and lengthy processes are required to obtain and renew approvals, permits, and licenses for new, existing, or modified energy-related facilities. Additionally, the u …

CommitmentsAndContingenciesDisclosureTextBlock · excerpt; the full note is in the filing

The following tables present disaggregated revenues by segment at Ameren and Ameren Illinois for the years ended December 31, 2025, 2024, and 2023. Economic factors affect the nature, timing, amount, and uncertainty of revenues and cash flows in a similar manner across customer classes. Revenues from alternative revenue programs have a similar distribution among customer classes as revenues from contracts with customers. Other revenues not associated with contracts with customers are presented in the Other customer classification, along with electric transmission and off-system sales and capacity revenues. Ameren Ameren Missouri Ameren Illinois Electric Distribution Ameren Illinois Natural Gas Ameren Transmission Intersegment Eliminations Ameren 2025 Residential $ 1,839 $ 1,483 $ $ $ $ 3,322 Commercial 1,450 785 2,235 Industrial 342 199 541 Other 1,000 (68) 862 (224) 1,570 Total electric revenues $ 4,631 $ 2,399 $ $ 862 $ (224) $ 7,668 Residential $ 101 $ $ 680 $ $ $ 781 Commercial 44 185 229 Industrial 5 12 17 Other 14 91 (1) 104 Total gas revenues $ 164 $ $ 968 $ $ (1) $ 1,131 Total revenues (a) $ 4,795 $ 2,399 $ 968 $ 862 $ (225) $ 8,799 2024 Residential $ 1,638 $ 1,254 $ $ $ $ 2,892 Commercial 1,313 680 1,993 Industrial 311 178 489 Other 585 (23) 781 (177) 1,166 Total electric revenues $ 3,847 $ 2,089 $ $ 781 $ (177) $ 6,540 Residential $ 90 $ $ 661 $ $ $ 751 Commercial 37 166 203 Industrial 4 10 14 Other 15 101 (1) 115 Total gas revenues $ 146 $ $ 938 $ $ (1) $ 1,083 Tot …

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STOCK-BASED COMPENSATION The 2022 Omnibus Incentive Compensation Plan is Amerens long-term incentive plan available for eligible employees and directors. It provides for a maximum of 8.8 million common shares to be available for grant to eligible employees and directors. At December 31, 2025, there were 7.3 million common shares remaining for grant. Awards may be restricted stock, restricted stock units, stock options (incentive stock options and nonqualified stock options), stock appreciation rights, performance awards, cash-based awards and other stock-based awards. Ameren used newly issued shares to fulfill its stock-based compensation obligations for 2025, 2024, and 2023, and intends to use newly issued shares to fulfill its stock-based compensation obligations for 2026. The following table summarizes Amerens outstanding performance share unit and restricted stock unit activity for the year ended December 31, 2025: Performance Share Units Market Condition (a) Performance Share Units Performance Condition (b) Restricted Stock Units Share Units Weighted-average Fair Value per Share Unit Share Units Weighted-average Fair Value per Share Unit Stock Units Weighted-average Fair Value per Stock Unit Outstanding at January 1, 2025 (c) 808,950 $ 77.73 120,997 $ 79.09 395,520 $ 79.73 Granted 245,464 123.19 40,408 96.66 132,931 97.33 Forfeitures (80,469) 87.56 (13,337) 82.09 (47,305) 83.77 Dividend equivalents (d) 22,947 87.13 3,452 82.34 10,968 82.72 Vested and distributed (217,017 …

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FAIR VALUE MEASUREMENTS Fair value is defined as the price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. We use various methods to determine fair value, including market, income, and cost approaches. With these approaches, we adopt certain assumptions that market participants would use in pricing the asset or liability, including assumptions about market risk or the risks inherent in the inputs to the valuation. Inputs to valuation can be readily observable, market-corroborated, or unobservable. We use valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs. Authoritative accounting guidance established a fair value hierarchy that prioritizes the inputs used to measure fair value. All financial assets and liabilities carried at fair value are classified and disclosed in one of the following three hierarchy levels: Level 1 (quoted prices in active markets for identical assets or liabilities): Inputs based on quoted prices in active markets for identical assets or liabilities. Level 1 assets and liabilities are primarily exchange-traded derivatives, cash and cash equivalents, and listed equity securities. The market approach is used to measure the fair value of equity securities held in Ameren Missouris nuclear decommissioning trust fund. Eq …

FairValueDisclosuresTextBlock · excerpt; the full note is in the filing

INCOME TAXES IRA The IRA was enacted in August 2022, and includes various income tax provisions, among other things. The law extends federal production and investment tax credits for projects beginning construction through 2024 and allows for a 10% adder to the production and investment tax credits for siting projects at existing energy communities as defined in the law, which includes sites previously used for coal-fired generation. The law also creates production and investment tax credits for projects beginning construction after 2024. The production and investment tax credits will apply to renewable energy production and investments, along with certain nuclear energy production. See the OBBBA below for additional information on revisions to the production and investment tax credits. The law allows for transferability, subject to revisions made by the OBBBA discussed below, to an unrelated party for cash of up to 100% of certain tax credits generated after 2022. In addition, the law imposes a 15% minimum tax on adjusted financial statement income, as defined in the law, for corporations whose average annual adjusted financial statement income exceeds $1 billion for three consecutive preceding tax years. Once a corporation exceeds this three-year average annual adjusted financial statement income threshold, it will be subject to the minimum tax for all future tax years. Additional regulations, interpretations, amendments, or technical corrections to or in connection with th …

IncomeTaxDisclosureTextBlock · excerpt; the full note is in the filing

RETIREMENT BENEFITS The primary objective of the Ameren pension and postretirement benefit plans is to provide eligible employees with pension and postretirement health care and life insurance benefits. Ameren has defined benefit pension plans covering substantially all of its employees and has a postretirement benefit plan covering non-union employees hired before October 2015 and union employees hired before January 2020. Ameren Missouri and Ameren Illinois each participate in Amerens single-employer pension and other postretirement plans. All non-union employees participate in a cash balance pension plan. Ameren Missouri union employees hired after June 2013, and Ameren Illinois union employees hired after mid-October 2012, participate in a cash balance pension plan. Ameren uses a measurement date of December 31 for its pension and postretirement benefit plans. Amerens qualified pension plan is the Ameren Retirement Plan. Amerens other postretirement plan is the Ameren Retiree Welfare Benefit Plan. Ameren also has an unfunded nonqualified pension plan, the Ameren Supplemental Retirement Plan, which is available to provide certain non-union employees and retirees with a supplemental benefit when their qualified pension plan benefits are capped in compliance with Internal Revenue Code limitations. Only Ameren subsidiaries participate in the plans listed above. Amerens pension and other postretirement benefit plans were overfunded by $954 million and $734 million in the aggre …

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RELATED-PARTY TRANSACTIONS In the normal course of business, Ameren Missouri and Ameren Illinois engage in affiliate transactions. These transactions primarily consist of natural gas and power purchases and sales, services received or rendered, and borrowings and lendings. Transactions between Amerens subsidiaries are reported as affiliate transactions on their individual financial statements, but those transactions are eliminated in consolidation for Amerens consolidated financial statements. Below are the material related-party agreements. Electric Power Supply Agreements Ameren Illinois must acquire capacity and energy sufficient to meet its obligations to customers. Ameren Illinois uses periodic RFP processes, administered by the IPA and approved by the ICC, to contract capacity and energy on behalf of its customers. Ameren Missouri participates in the RFP process and has been a winning supplier for certain periods. Capacity Supply Agreements In procurement events in 2021, Ameren Missouri contracted to supply a portion of Ameren Illinois capacity requirements for $2 million from June 2022 through May 2023. Energy Product Agreements Based on the outcome of an IPA-administered procurement event in 2021, Ameren Missouri and Ameren Illinois have entered into an energy product agreement by which Ameren Missouri agreed to sell, and Ameren Illinois agreed to purchase, 136,000 MWhs at an average price of $37 per MWh from January 2022 through September 2023. Interconnection Agreem …

RelatedPartyTransactionsDisclosureTextBlock · excerpt; the full note is in the filing

SEGMENT INFORMATION Ameren has four segments: Ameren Missouri, Ameren Illinois Electric Distribution, Ameren Illinois Natural Gas, and Ameren Transmission. The Ameren Missouri segment includes all of the operations of Ameren Missouri. Ameren Illinois Electric Distribution consists of the electric distribution business of Ameren Illinois. Ameren Illinois Natural Gas consists of the natural gas business of Ameren Illinois. Ameren Transmission primarily consists of the aggregated electric transmission businesses of Ameren Illinois and ATXI. The category called Other primarily includes Ameren (parent) activities and Ameren Services. Ameren Missouri has one segment. Ameren Illinois has three segments: Ameren Illinois Electric Distribution, Ameren Illinois Natural Gas, and Ameren Illinois Transmission. See Note 1 Summary of Significant Accounting Policies for additional information regarding the operations of Ameren Missouri, Ameren Illinois, and ATXI. Segment operating revenues and a majority of operating expenses are directly recognized and incurred by Ameren Illinois in each Ameren Illinois segment. Common operating expenses, miscellaneous income and expenses, interest charges, and income tax expense are allocated by Ameren Illinois to each Ameren Illinois segment based on certain factors, which primarily relate to the nature of the cost. Additionally, Ameren Illinois Transmission earns revenue from transmission service provided to Ameren Illinois Electric Distribution, other re …

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SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES General Ameren, headquartered in St. Louis, Missouri, is a public utility holding company whose primary assets are its equity interests in its subsidiaries. Amerens subsidiaries are separate, independent legal entities with separate businesses, assets, and liabilities. Dividends on Amerens common stock and the payment of expenses by Ameren depend on distributions made to it by its subsidiaries. Amerens principal subsidiaries are listed below. Ameren also has other subsidiaries that conduct other activities, such as providing shared services. Union Electric Company, doing business as Ameren Missouri, operates a rate-regulated electric generation, transmission, and distribution business and a rate-regulated natural gas distribution business in Missouri. Ameren Missouri was incorporated in Missouri in 1922 and is successor to a number of companies, the oldest of which was organized in 1881. It is the largest electric utility in the state of Missouri. It supplies electric and natural gas service to a 24,000-square-mile area in central and eastern Missouri, which includes the Greater St. Louis area. Ameren Missouri supplies electric service to 1.3 million customers and natural gas service to 0.1 million customers. Ameren Illinois Company, doing business as Ameren Illinois, operates rate-regulated electric transmission, electric distribution, and natural gas distribution businesses in Illinois. Ameren Illinois was incorporated in Illinois …

SignificantAccountingPoliciesTextBlock · excerpt; the full note is in the filing

COMMITMENTS AND CONTINGENCIES We are involved in legal, tax, and regulatory proceedings before various courts, regulatory commissions, authorities, and governmental agencies with respect to matters that arise in the ordinary course of business, some of which involve substantial amounts of money. We believe that the final disposition of these proceedings, except as otherwise disclosed in the notes to our financial statements in this report and in the Form 10-K, will not have a material adverse effect on our results of operations, financial position, or liquidity. Reference is made to Note 1 Summary of Significant Accounting Policies, Note 2 Rate and Regulatory Matters, Note 9 Callaway Energy Center, Note 13 Related-party Transactions, and Note 14 Commitments and Contingencies under Part II, Item 8, of the Form 10-K. See also Note 1 Summary of Significant Accounting Policies, Note 2 Rate and Regulatory Matters, Note 8 Related-party Transactions, and Note 10 Callaway Energy Center of this report. Environmental Matters Our electric generation, transmission, and distribution and natural gas distribution and storage operations must comply with a variety of statutes and regulations relating to the protection of the environment and human health and safety, including permitting programs implemented by federal, state, and local authorities. Such environmental laws regulate air emissions; protect water bodies; regulate the handling and disposal of hazardous substances and waste material …

CommitmentsAndContingenciesDisclosureTextBlock · excerpt; the full note is in the filing

The following tables present disaggregated revenues by segment at Ameren and Ameren Illinois for the three and nine months ended September 30, 2025 and 2024. Economic factors affect the nature, timing, amount, and uncertainty of revenues and cash flows in a similar manner across customer classes. Revenues from alternative revenue programs have a similar distribution among customer classes as revenues from contracts with customers. Other revenues not associated with contracts with customers are presented in the Other customer classification, along with electric transmission, off-system sales, and capacity revenues. Ameren Ameren Missouri Ameren Illinois Electric Distribution Ameren Illinois Natural Gas Ameren Transmission Intersegment Eliminations Ameren Three Months 2025: Residential $ 702 $ 469 $ $ $ $ 1,171 Commercial 537 235 772 Industrial 119 46 165 Other 327 (51) (a) 240 (61) 455 Total electric revenues $ 1,685 $ 699 $ $ 240 $ (61) $ 2,563 Residential $ 9 $ $ 70 $ $ $ 79 Commercial 5 21 26 Industrial 2 2 Other 6 24 (1) 29 Total natural gas revenues $ 20 $ $ 117 $ $ (1) $ 136 Total revenues (b) $ 1,705 $ 699 $ 117 $ 240 $ (62) $ 2,699 Three Months 2024: Residential $ 590 $ 339 $ $ $ $ 929 Commercial 465 184 649 Industrial 108 38 146 Other 161 (9) (a) 210 (51) 311 Total electric revenues $ 1,324 $ 552 $ $ 210 $ (51) $ 2,035 Residential $ 9 $ $ 77 $ $ $ 86 Commercial 5 19 24 Industrial 2 2 Other 4 23 (1) 26 Total natural gas revenues $ 18 $ $ 121 $ $ (1) $ 138 Total revenue …

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FAIR VALUE MEASUREMENTS Fair value is defined as the price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Fair value measurements are classified in three levels based on the fair value hierarchy as defined by GAAP. See Note 8 Fair Value Measurements under Part II, Item 8, of the Form 10-K for information related to hierarchy levels and valuation techniques. We consider nonperformance risk in our valuation of derivative instruments by analyzing our own credit standing and the credit standing of our counterparties, and by considering any credit enhancements (e.g., collateral). Included in our valuation, and based on current market conditions, is a valuation adjustment for counterparty default derived from market data such as the price of credit default swaps, bond yields, and credit ratings. No material gains or losses related to valuation adjustments for counterparty default risk were recorded at Ameren, Ameren Missouri, or Ameren Illinois in the three and nine months ended September 30, 2025 or 2024. At September 30, 2025, and December 31, 2024, the counterparty default risk valuation adjustment related to derivative contracts was immaterial for Ameren, Ameren Missouri, and Ameren Illinois. The following table sets forth, by level within the fair value hierarchy, our assets and liabilities m …

FairValueDisclosuresTextBlock · excerpt; the full note is in the filing

INCOME TAXES OBBBA The OBBBA was enacted in July 2025 and includes various income tax provisions, among other things. The OBBBA modified provisions of the IRA related to production and investment tax credits. The new law maintains production and investment tax credits for solar and wind projects that begin construction within one year of the OBBBAs enactment and are placed in-service by the end of 2030. Projects that begin construction after one year from enactment of the OBBBA but are placed in service by the end of 2027 also remain eligible. The law provides investment tax credits for battery storage projects that begin construction by the end of 2033 and phase out by the end of 2035. Renewable energy projects that begin construction in 2026 and beyond that use a certain threshold percentage of materials from prohibited foreign entities, as defined in the OBBBA, are not eligible for the tax credits. Production tax credits associated with nuclear generation remain unchanged from the IRA and phase out by the end of 2032. Furthermore, the new law continues to allow for transferability of the production and investment tax credits to an unrelated party for cash but is restricted from being transferred to specified foreign entities, as defined in the OBBBA. Ameren is currently evaluating the OBBBA and guidance issued in connection with the OBBBA and does not expect any material impacts on its results of operations, financial position, and liquidity in 2025. Implementation of the …

IncomeTaxDisclosureTextBlock · excerpt; the full note is in the filing

RETIREMENT BENEFITS The following table presents the components of the net periodic benefit cost (income) incurred for Amerens pension and postretirement benefit plans for the three and nine months ended September 30, 2025 and 2024: Pension Benefits Postretirement Benefits Three Months Nine Months Three Months Nine Months 2025 2024 2025 2024 2025 2024 2025 2024 Service cost (a) $ 21 $ 22 $ 62 $ 66 $ 3 $ 3 $ 8 $ 9 Non-service cost components: Interest cost 58 56 175 167 11 11 33 33 Expected return on plan assets (b) (76) (82) (227) (246) (24) (23) (71) (69) Amortization of (b) : Prior service cost (credit) (1) (1) (3) (3) Actuarial (gain) (9) (17) (26) (50) (9) (9) (27) (29) Total non-service cost components (c) $ (27) $ (43) $ (78) $ (129) $ (23) $ (22) $ (68) $ (68) Net periodic benefit income (d) $ (6) $ (21) $ (16) $ (63) $ (20) $ (19) $ (60) $ (59) (a) Service cost, net of capitalization, is reflected in Operating Expenses Other operations and maintenance on Amerens statement of income. (b) Prior service cost (credit) is amortized on a straight-line basis over the average future service of active participants benefiting under a plan amendment. Net actuarial gains or losses related to the net benefit obligation subject to amortization are amortized on a straight-line basis over 10 years. The difference between the actual and expected return on plan assets is amortized over 4 years. (c) Non-service cost components are reflected in Other Income, Net on Amerens consolidated s …

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RELATED-PARTY TRANSACTIONS In the ordinary course of business, Ameren Missouri and Ameren Illinois have engaged in, and may in the future engage in, affiliate transactions. These transactions primarily consist of natural gas and power purchases and sales, services received or rendered, and borrowings and lendings. Transactions between Amerens subsidiaries are reported as affiliate transactions on their individual financial statements, but those transactions are eliminated in consolidation for Amerens consolidated financial statements. For a discussion of material related-party agreements and money pool agreements, see Note 13 Related-party Transactions and Note 4 Short-term Debt and Liquidity under Part II, Item 8, of the Form 10-K. Support Services Agreements Ameren Missouri and Ameren Illinois had long-term receivables included in Other assets from Ameren Services of $18 million and $20 million, respectively, as of September 30, 2025, and $29 million and $32 million, respectively, as of December 31, 2024, related to Ameren Services allocated portion of Amerens pension and postretirement benefit plans. Tax Allocation Agreement See Note 1 Summary of Significant Accounting Policies under Part II, Item 8, of the Form 10-K for a discussion of the tax allocation agreement. The following table presents the affiliate balances related to income taxes for Ameren Missouri and Ameren Illinois as of September 30, 2025, and December 31, 2024: September 30, 2025 December 31, 2024 Ameren M …

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SEGMENT INFORMATION The following tables present revenues, net income attributable to common shareholders, and capital expenditures by segment at Ameren and Ameren Illinois for the three and nine months ended September 30, 2025 and 2024. Ameren, Ameren Missouri, and Ameren Illinois management review segment capital expenditure information rather than any individual or total asset amount. For additional information about our segments, see Note 16 Segment Information under Part II, Item 8, of the Form 10-K. Ameren Ameren Missouri Ameren Illinois Electric Distribution Ameren Illinois Natural Gas Ameren Transmission Other Intersegment Eliminations Ameren Three Months 2025: External revenues $ 1,696 $ 698 $ 117 $ 188 $ $ $ 2,699 Intersegment revenues 9 1 52 (62) Revenue 1,705 699 117 240 (62) 2,699 Fuel and purchased power (a) (487) (330) 49 (768) Natural gas purchased for resale (a) (6) (19) (25) Other operations and maintenance expenses (a) (260) (171) (55) (19) (10) 13 (502) Other segment items Depreciation and amortization (239) (92) (33) (49) (2) (415) Taxes other than income taxes (122) (22) (15) (3) (2) (164) Other income (expense), net 45 20 4 (3) 11 (1) 76 Interest charges (85) (28) (16) (31) (49) 1 (208) Income taxes (benefit) (32) (19) 4 16 (21) (52) Noncontrolling interests preferred stock dividends (1) (1) Net income (loss) attributable to Ameren common shareholders 518 57 (13) 151 (b) (73) 640 Interest income 3 6 1 1 (1) 10 Capital expenditures 548 163 78 174 1 24 98 …

SegmentReportingDisclosureTextBlock · excerpt; the full note is in the filing

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES General Ameren, headquartered in St. Louis, Missouri, is a public utility holding company whose primary assets are its equity interests in its subsidiaries. Amerens subsidiaries are separate, independent legal entities with separate businesses, assets, and liabilities. Dividends on Amerens common stock and the payment of expenses by Ameren depend on distributions made to it by its subsidiaries. Amerens principal subsidiaries are listed below. Ameren also has other subsidiaries that conduct other activities, such as providing shared services. Union Electric Company, doing business as Ameren Missouri, operates a rate-regulated electric generation, transmission, and distribution business and a rate-regulated natural gas distribution business in Missouri. Ameren Illinois Company, doing business as Ameren Illinois, operates rate-regulated electric transmission, electric distribution, and natural gas distribution businesses in Illinois. ATXI operates a FERC rate-regulated electric transmission business within the MISO. Amerens and Ameren Missouris financial statements are prepared on a consolidated basis and therefore include the accounts of their majority-owned subsidiaries. All intercompany transactions have been eliminated. Ameren Illinois has no subsidiaries. All tabular dollar amounts are in millions, unless otherwise indicated. Our accounting policies conform to GAAP. Our financial statements reflect all adjustments (which include no …

SignificantAccountingPoliciesTextBlock · excerpt; the full note is in the filing