Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2026

Schedule Of Fair Value Hierarchy Of Assets And Liabilities Measured At Fair Value On Recurring Basis

The following table sets forth, by level within the fair value hierarchy, our assets and liabilities measured at fair value on a recurring basis as of June 30, 2026, and December 31, 2025:


		June 30, 2026									December 31, 2025
		Level 1		Level 2		Level 3		Total			Level 1		Level 2		Level 3		Total
Assets:
Ameren Missouri
	Derivative assets – commodity contracts:
	Fuel oils	$	10	$	—	$	1	$	11		$	—	$	—	$	—	$	—
	Natural gas	—		—		—		—			—		1		—		1
	Power	—		15		17		32			—		—		11		11

	Total derivative assets – commodity contracts	$	10	$	15	$	18	$	43		$	—	$	1	$	11	$	12
	Nuclear decommissioning trust fund:

	Equity securities:
	U.S. large capitalization	$	1,135	$	—	$	—	$	1,135		$	1,028	$	—	$	—	$	1,028
	Debt securities:
	U.S. Treasury and agency securities	—		197		—		197			—		225		—		225
	Corporate bonds	—		184		—		184			—		177		—		177


	Other	—		105		—		105			—		84		—		84
	Total nuclear decommissioning trust fund	$	1,135	$	486	$	—	$	1,621	(a)	$	1,028	$	486	$	—	$	1,514	(a)
	Total Ameren Missouri	$	1,145	$	501	$	18	$	1,664		$	1,028	$	487	$	11	$	1,526
Ameren Illinois
	Derivative assets – commodity contracts:
	Natural gas	$	—	$	—	$	2	$	2		$	—	$	2	$	2	$	4

	Total Ameren Illinois	$	—	$	—	$	2	$	2		$	—	$	2	$	2	$	4
Ameren
	Derivative assets – commodity contracts(b)	$	10	$	15	$	20	$	45		$	—	$	3	$	13	$	16
	Nuclear decommissioning trust fund(c)	1,135		486		—		1,621		(a)	1,028		486		—		1,514		(a)
	Total Ameren	$	1,145	$	501	$	20	$	1,666		$	1,028	$	489	$	13	$	1,530
Liabilities:
Ameren Missouri
	Derivative liabilities – commodity contracts:
	Fuel oils	$	—	$	—	$	—	$	—		$	5	$	—	$	—	$	5
	Natural gas	—		14		1		15			—		10		—		10
	Power	—		1		—		1			—		—		—		—

	Total Ameren Missouri	$	—	$	15	$	1	$	16		$	5	$	10	$	—	$	15
Ameren Illinois
	Derivative liabilities – commodity contracts:
	Natural gas	$	2	$	41	$	4	$	47		$	1	$	28	$	3	$	32
	Power	24		—		39		63			—		13		66		79
	Total Ameren Illinois	$	26	$	41	$	43	$	110		$	1	$	41	$	69	$	111
Ameren
	Derivative liabilities – commodity contracts(b)	$	26	$	56	$	44	$	126		$	6	$	51	$	69	$	126

(a)Balance excludes $10 million and $12 million of cash and cash equivalents, receivables, payables, and accrued income, net, for June 30, 2026, and December 31, 2025, respectively.

(b)See the Ameren Missouri and Ameren Illinois sections of the table for a breakout of the fair value of Ameren’s derivative assets and liabilities by type of commodity.

(c)See the Ameren Missouri section of the table for a breakout of the fair value of Ameren’s nuclear decommissioning trust fund by investment type.

Schedule Of Changes In The Fair Value Of Financial Assets And Liabilities Classified As Level Three In The Fair Value Hierarchy

The following table presents the fair value reconciliation of Level 3 power derivative contract assets and liabilities measured at fair value on a recurring basis for the three and six months ended June 30, 2026:


	2026
	Ameren Missouri		Ameren Illinois		Ameren
For the three months ended June 30:
Beginning balance at April 1	$	3	$	(56)	$	(53)
Realized and unrealized gains/(losses) included in regulatory assets/liabilities	17		7		24


Settlements	(3)		4		1

Transfers out of Level 3	—		6		6
Ending balance at June 30	$	17	$	(39)	$	(22)
Change in unrealized gains/(losses) related to assets/liabilities held at June 30	$	17	$	8	$	25
For the six months ended June 30:
Beginning balance at January 1	$	11	$	(66)	$	(55)
Realized and unrealized gains/(losses) included in regulatory assets/liabilities	13		9		22


Settlements	(7)		5		(2)

Transfers out of Level 3	—		13		13
Ending balance at June 30	$	17	$	(39)	$	(22)
Change in unrealized gains/(losses) related to assets/liabilities held at June 30	$	16	$	8	$	24

Fair Value, Assets and Liabilities Measured on Nonrecurring Basis, Valuation Techniques

The following table describes the valuation techniques and significant unobservable inputs utilized for the fair value of our Level 3 power derivative contract assets and liabilities as of June 30, 2026, and December 31, 2025:


			Fair Value						Weighted Average(b)
	Commodity		Assets		Liabilities	Valuation Technique(s)	Unobservable Input(a)	Range
2026	Power(c)	$	17	$	(39)	Discounted cash flow	Average forward peak and off-peak pricing – forwards/swaps ($/MWh)	33 – 73	46

							Nodal basis ($/MWh)	(12) – 0	(6)


2025	Power(c)	$	11	$	(66)	Discounted cash flow	Average forward peak and off-peak pricing – forwards/swaps ($/MWh)	33 – 72	43

							Nodal basis ($/MWh)	(9) – (2)	(5)

(a)Generally, significant increases (decreases) in these inputs in isolation would result in a significantly higher (lower) fair value measurement.

(b)Unobservable inputs were weighted by relative fair value.

(c)Valuations use visible forward prices adjusted for nodal-to-hub basis differentials.

Schedule of Financial Assets and Liabilities

The following table sets forth the carrying amount and, by level within the fair value hierarchy, the fair value of long-term debt (including current portion) disclosed, but not recorded, at fair value as of June 30, 2026, and December 31, 2025:


Long-Term Debt (Including Current Portion):	Carrying Amount(a)		Fair Value
			Level 2		Level 3			Total
	June 30, 2026




Ameren(b)	$	20,588	$	18,684	$	550	(c)	$	19,234






Ameren Missouri(d)	9,602		8,923		—			8,923





Ameren Illinois(d)	6,261		5,698		—			5,698
	December 31, 2025



Ameren(b)	$	19,187	$	17,433	$	559	(c)	$	17,992






Ameren Missouri(d)	8,230		7,608		—			7,608




Ameren Illinois(d)	6,259		5,753		—			5,753

(a)Included unamortized debt issuance costs, which were excluded from the fair value measurement, of $148 million, $73 million, and $54 million for Ameren, Ameren Missouri, and Ameren Illinois, respectively, as of June 30, 2026. Included unamortized debt issuance costs, which were excluded from the fair value measurement, of $136 million, $62 million, and $56 million for Ameren, Ameren Missouri, and Ameren Illinois, respectively, as of December 31, 2025.

(b)Amount excludes Ameren (parent)’s repurchase of Ameren Missouri’s senior secured notes and first mortgage bonds and Ameren Illinois’ first mortgage bonds that were accounted for as a debt extinguishment. See Note 4 – Long-term Debt and Equity Financings above and Note 5 – Long-term Debt and Equity Financings under Part II, Item 8, of the Form 10-K for additional information.

(c)The Level 3 fair value amount consists of ATXI’s senior unsecured notes.

(d)Amount includes Ameren Missouri’s senior secured notes and first mortgage bonds and Ameren Illinois’ first mortgage bonds that were repurchased by Ameren (parent).

- Definition

Tabular disclosure of the fair value measurement of assets using significant unobservable inputs (Level 3), a reconciliation of the beginning and ending balances, separately presenting changes during the period attributable to the following: (1) total gains or losses for the period (realized and unrealized), segregating those gains or losses included in earnings (or changes in net assets) and gains or losses recognized in other comprehensive income (loss), and a description of where those gains or losses included in earnings (or changes in net assets) are reported in the statement of income (or activities); (2) purchases, sales, issues, and settlements (each type disclosed separately); and (3) transfers in and transfers out of Level 3 (for example, transfers due to changes in the observability of significant inputs), by class of asset.

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