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Summary Of Significant Accounting Policies (Policies) | 3 Months Ended
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Mar. 31, 2025
Accounting Policies [Abstract] |
Nature of Operations | Ameren, headquartered in St. Louis, Missouri, is a public utility holding company whose primary assets are its equity interests in its subsidiaries. Ameren’s subsidiaries are separate, independent legal entities with separate businesses, assets, and liabilities. Dividends on Ameren’s common stock and the payment of expenses by Ameren depend on distributions made to it by its subsidiaries. Ameren’s 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.
Consolidation | Ameren’s and Ameren Missouri’s 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.
Consolidation, Variable Interest Entity, Policy | Variable Interest Entities Variable Interest Entities that are Consolidated AMF was formed in 2024, for the purpose of issuing and servicing securitized utility tariff bonds related to costs for the accelerated retirement of the Rush Island Energy Center. Ameren Missouri is the primary beneficiary of this entity because it has the power to direct the activities that most significantly impact the economic performance of the company, as well as the obligation to absorb losses or the right to receive benefits from the company. The entity is considered a variable interest entity primarily because its equity capitalization is insufficient to support its operations. The entity’s primary assets and liabilities are comprised of regulatory assets related to the unrecovered net plant balance associated with the facility, among other costs, and long-term debt. Ameren and Ameren Missouri consolidate AMF, which Ameren Missouri wholly owns, and both manages and controls the entity’s operating activities. For additional information on the securitization of the Rush Island Energy Center costs, see Note 2 – Rate and Regulatory Matters under Part II, Item 8, of the Form 10-K. For additional information on the securitized tariff bond issuance, see Note 5 – Long-term Debt and Equity Financings under Part II, Item 8, of the Form 10‑K. The following table presents the carrying values of AMF’s assets and liabilities included on Ameren’s and Ameren Missouri’s consolidated balance sheets as of March 31, 2025 and December 31, 2024:
|  | 2025 |  | 2024
Unbilled revenue(a) |  | $ | 2 |  |  | $ | — |
Other current assets(a) |  | 15 |  |  | 2 |
Noncurrent regulatory assets(a) |  | 459 |  |  | 465 |
Current maturities of long-term debt(b) |  | 17 |  |  | 17 |
Interest accrued (b) |  | 6 |  |  | 1 |
Current regulatory liabilities(c) |  | 5 |  |  | — |
Long-term debt, net(b) |  | 449 |  |  | 448 |
(a)Assets may be used only to meet AMF’s obligations and commitments. (b)The securitized tariff bondholders have no recourse to Ameren Missouri. (c)Included in “Other current liabilities” on Ameren Missouri’s balance sheet. Variable Interest Entities that are Not Consolidated As of March 31, 2025, and December 31, 2024, Ameren had unconsolidated variable interests in various equity method investments, primarily to advance clean and resilient energy technologies, totaling $71 million and $74 million, respectively, included in “Other assets” on Ameren’s consolidated balance sheet. Any earnings or losses related to these investments are included in “Other Income, Net” on Ameren’s consolidated statement of income and comprehensive income. Ameren is not the primary beneficiary of these investments because it does not have the power to direct matters that most significantly affect the activities of these variable interest entities. As of March 31, 2025, Ameren’s maximum exposure to loss related to these variable interest entities is limited to the investment in these partnerships of $71 million plus associated outstanding funding commitments of $34 million.
Life Insurance, Corporate Or Bank Owned | COLI Ameren (parent) and Ameren Illinois have COLI, which is recorded at the net cash surrender value. The net cash surrender value is the amount that can be realized under the insurance policies at the balance sheet date.
Derivatives, Policy | If we determine that a contract meets the definition of a derivative and is not eligible for the NPNS exception, we review the contract to determine whether the resulting gains or losses qualify for regulatory deferral. Derivative contracts that qualify for regulatory deferral are recorded at fair value, with changes in fair value recorded as regulatory assets or liabilities in the period in which the change occurs. We believe derivative losses and gains deferred as regulatory assets and liabilities are probable of recovery, or refund, through future rates charged to customers. Regulatory assets and liabilities are amortized to operating income as related losses and gains are reflected in rates charged to customers. Therefore, gains and losses on these derivatives have no effect on operating income.
Deferred Compensation | Deferred Compensation At March 31, 2025, and December 31, 2024, the present value of benefits to be paid for deferred compensation obligations was $79 million and $79 million, respectively, which was primarily reflected in “Other deferred credits and liabilities” on Ameren’s consolidated balance sheet.
Revenue from Contract with Customer | Operating Revenues As of March 31, 2025 and 2024, our remaining performance obligations for contracts with a term greater than one year were immaterial. The Ameren Companies elected not to disclose the aggregate amount of the transaction price allocated to the performance obligations that are unsatisfied as of the end of the reporting period for contracts with an initial expected term of one year or less. See Note 14 – Segment Information for disaggregated revenue information.
Excise Taxes | Excise Taxes Ameren Missouri and Ameren Illinois collect from their customers excise taxes, including municipal and state excise taxes and gross receipts taxes that are levied on the sale or distribution of natural gas and electricity.

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