Item 1. FINANCIAL STATEMENTS.

AMEREN CORPORATION

CONSOLIDATED STATEMENT OF INCOME AND COMPREHENSIVE INCOME

(Unaudited) (In millions, except per share amounts)

			Three Months Ended September 30,												Nine Months Ended September 30,
			2025						2024						2025						2024
Operating Revenues:
Electric			$	2,563					$	2,035					$	6,223					$	4,920
Natural gas			136						138						794						762
Total operating revenues			2,699						2,173						7,017						5,682
Operating Expenses:
Fuel and purchased power			768						499						2,064						1,154
Natural gas purchased for resale			25						30						233						214
Other operations and maintenance			502						520						1,447						1,455
Depreciation and amortization			415						388						1,168						1,125
Taxes other than income taxes			164						150						439						416
Total operating expenses			1,874						1,587						5,351						4,364
Operating Income			825						586						1,666						1,318
Other Income, Net			76						101						257						293
Interest Charges			208						173						570						492
Income Before Income Taxes			693						514						1,353						1,119
Income Taxes			52						57						145						140
Net Income			641						457						1,208						979
Less: Net Income Attributable to Noncontrolling Interests			1						1						4						4
Net Income Attributable to Ameren Common Shareholders			$	640					$	456					$	1,204					$	975
Net Income			$	641					$	457					$	1,208					$	979
Other Comprehensive Income (Loss), Net of Taxes
Pension and other postretirement benefit plan activity, net of income taxes (benefit) of $—, $—, $(1), and $(1) respectively			—						(1)						(2)						(4)
Unrealized net loss on derivative hedging instruments, net of income taxes (benefit) of $—, $—, $(1), and $—, respectively			—						—						(6)						—
Comprehensive Income			641						456						1,200						975
Less: Comprehensive Income Attributable to Noncontrolling Interests			1						1						4						4
Comprehensive Income Attributable to Ameren Common Shareholders			$	640					$	455					$	1,196					$	971
Earnings per Common Share - Basic			$	2.37					$	1.71					$	4.46					$	3.66
Earnings per Common Share – Diluted			$	2.35					$	1.70					$	4.43					$	3.65
Weighted-average Common Shares Outstanding – Basic			270.4						266.8						270.2						266.6
Weighted-average Common Shares Outstanding – Diluted			272.2						267.3						271.7						266.9

The accompanying notes are an integral part of these consolidated financial statements.

AMEREN CORPORATION

CONSOLIDATED BALANCE SHEET

(Unaudited) (In millions, except per share amounts)

			September 30, 2025						December 31, 2024
ASSETS
Current Assets:
Cash and cash equivalents			$	9					$	7
Accounts receivable – trade (less allowance for doubtful accounts of $38 and $30, respectively)			794						525
Unbilled revenue			413						346
Miscellaneous accounts receivable			78						96
Inventories			804						762
Current regulatory assets			260						366
Other current assets (includes $46 and $2 related to VIEs, respectively)			252						162
Total current assets			2,610						2,264
Property, Plant, and Equipment, Net			38,411						36,304
Investments and Other Assets:
Nuclear decommissioning trust fund			1,502						1,342
Goodwill			411						411
Regulatory assets (includes $449 and $465 related to VIEs, respectively)			2,611						2,397
Pension and other postretirement benefits			741						757
Other assets			1,130						1,123
Total investments and other assets			6,395						6,030
TOTAL ASSETS			$	47,416					$	44,598
LIABILITIES AND EQUITY
Current Liabilities:
Current maturities of long-term debt (includes $29 and $17 related to VIEs, respectively)			$	29					$	317
Short-term debt			903						1,143
Accounts and wages payable			762						1,059
Taxes accrued			215						60
Interest accrued			183						196
Customer deposits			248						223
Current regulatory liabilities			142						120
Other current liabilities			323						295
Total current liabilities			2,805						3,413
Long-term Debt, Net (includes $437 and $448 related to VIEs, respectively)			19,172						17,262
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes and tax credits, net			5,081						4,474
Regulatory liabilities			6,089						5,897
Asset retirement obligations			844						822
Other deferred credits and liabilities			516						487
Total deferred credits and other liabilities			12,530						11,680
Commitments and Contingencies (Notes 2, 9, and 10)
Shareholders’ Equity:
Common stock, $.01 par value, 400.0 shares authorized – shares outstanding of 270.5 and 269.9, respectively			3						3
Other paid-in capital, principally premium on common stock			7,559						7,513
Retained earnings			5,232						4,604
Accumulated other comprehensive loss			(14)						(6)
Total shareholders’ equity			12,780						12,114
Noncontrolling Interests			129						129
Total equity			12,909						12,243
TOTAL LIABILITIES AND EQUITY			$	47,416					$	44,598

The accompanying notes are an integral part of these consolidated financial statements.

AMEREN CORPORATION
CONSOLIDATED STATEMENT OF CASH FLOWS
(Unaudited) (In millions)
			Nine Months Ended September 30,
			2025						2024
Cash Flows From Operating Activities:
Net income			$	1,208					$	979
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization			1,199						1,142
Amortization of nuclear fuel			39						59
Amortization of debt issuance costs and premium/discounts			14						14
Deferred income taxes and tax credits, net			255						145
Allowance for equity funds used during construction			(60)						(48)
Stock-based compensation costs			21						22
Other			29						84
Changes in assets and liabilities:
Receivables			(356)						(183)
Inventories			(41)						(60)
Accounts and wages payable			(244)						(239)
Taxes accrued			307						176
Regulatory assets and liabilities			97						86
Assets, other			(29)						(59)
Liabilities, other			72						(4)
Pension and other postretirement benefits			(114)						(168)
Net cash provided by operating activities			2,397						1,946
Cash Flows From Investing Activities:
Capital expenditures			(3,118)						(3,029)
Nuclear fuel expenditures			(20)						(57)
Purchases of securities – nuclear decommissioning trust fund			(373)						(499)
Sales and maturities of securities – nuclear decommissioning trust fund			348						480
Other			51						(1)
Net cash used in investing activities			(3,112)						(3,106)
Cash Flows From Financing Activities:
Dividends on common stock			(576)						(535)
Dividends paid to noncontrolling interest holders			(4)						(4)
Short-term debt, net			(239)						1,002
Maturities and extinguishment of long-term debt			(324)						(849)
Issuances of long-term debt			1,960						1,610
Issuances of common stock			35						30
Employee payroll taxes related to stock-based compensation			(13)						(8)
Debt issuance costs			(17)						(19)
Other			—						(15)
Net cash provided by financing activities			822						1,212
Net change in cash, cash equivalents, and restricted cash			107						52
Cash, cash equivalents, and restricted cash at beginning of year			328						272
Cash, cash equivalents, and restricted cash at end of period			$	435					$	324

The accompanying notes are an integral part of these consolidated financial statements.

AMEREN CORPORATION

CONSOLIDATED STATEMENT OF SHAREHOLDERS’ EQUITY

(Unaudited) (In millions, except per share amounts)

			Three Months Ended September 30,												Nine Months Ended September 30,
			2025						2024						2025						2024
Common Stock			$	3					$	3					$	3					$	3
Other Paid-in Capital:
Beginning of period			7,541						7,246						7,513						7,216
Shares issued under the DRPlus and 401(k) plan			10						9						35						30
Stock-based compensation activity			8						9						11						18
Other paid-in capital, end of period			7,559						7,264						7,559						7,264
Retained Earnings:
Beginning of period			4,784						4,299						4,604						4,136
Net income attributable to Ameren common shareholders			640						456						1,204						975
Dividends on common stock			(192)						(179)						(576)						(535)
Retained earnings, end of period			5,232						4,576						5,232						4,576
Accumulated Other Comprehensive Loss:
Derivative financial instruments, beginning of period			(3)						—						3						—
Change in derivative financial instruments			—						—						(6)						—
Derivative financial instruments, end of period			(3)						—						(3)						—
Deferred retirement benefit costs, beginning of period			(11)						(9)						(9)						(6)
Change in deferred retirement benefit costs			—						(1)						(2)						(4)
Deferred retirement benefit costs, end of period			(11)						(10)						(11)						(10)
Total accumulated other comprehensive loss, end of period			(14)						(10)						(14)						(10)
Total Shareholders’ Equity			$	12,780					$	11,833					$	12,780					$	11,833
Noncontrolling Interests:
Beginning of period			129						129						129						129
Net income attributable to noncontrolling interest holders			1						1						4						4
Dividends paid to noncontrolling interest holders			(1)						(1)						(4)						(4)
Noncontrolling interests, end of period			129						129						129						129
Total Equity			$	12,909					$	11,962					$	12,909					$	11,962
Common stock shares outstanding at beginning of period			270.4						266.8						269.9						266.3
Shares issued under the DRPlus and 401(k) plan			0.1						0.1						0.3						0.4
Shares issued for stock-based compensation			—						—						0.3						0.2
Common stock shares outstanding at end of period			270.5						266.9						270.5						266.9
Dividends per common share			$	0.71					$	0.67					$	2.13					$	2.01

The accompanying notes are an integral part of these consolidated financial statements.

UNION ELECTRIC COMPANY (d/b/a AMEREN MISSOURI)

CONSOLIDATED STATEMENT OF INCOME

(Unaudited) (In millions)

			Three Months Ended September 30,												Nine Months Ended September 30,
			2025						2024						2025						2024
Operating Revenues:
Electric			$	1,685					$	1,324					$	3,893					$	2,902
Natural gas			20						18						109						103
Total operating revenues			1,705						1,342						4,002						3,005
Operating Expenses:
Fuel and purchased power			487						334						1,431						689
Natural gas purchased for resale			6						4						45						41
Other operations and maintenance			260						288						748						789
Depreciation and amortization			239						220						642						623
Taxes other than income taxes			122						109						300						287
Total operating expenses			1,114						955						3,166						2,429
Operating Income			591						387						836						576
Other Income, Net			45						51						135						144
Interest Charges			85						62						215						187
Income Before Income Taxes			551						376						756						533
Income Taxes (Benefit)			32						(6)						43						(4)
Net Income			519						382						713						537
Preferred Stock Dividends			1						1						3						3
Net Income Available to Common Shareholder			$	518					$	381					$	710					$	534

The accompanying notes as they relate to Ameren Missouri are an integral part of these consolidated financial statements.

UNION ELECTRIC COMPANY (d/b/a AMEREN MISSOURI)

CONSOLIDATED BALANCE SHEET

(Unaudited) (In millions, except per share amounts)

			September 30, 2025						December 31, 2024
ASSETS
Current Assets:
Cash and cash equivalents			$	—					$	—
Restricted cash (includes $46 and $2 related to VIEs, respectively)			86						7
Advances to money pool			—						43
Accounts receivable – trade (less allowance for doubtful accounts of $15 and $12, respectively)			359						209
Accounts receivable – affiliates			24						40
Unbilled revenue			267						170
Miscellaneous accounts receivable			9						33
Inventories			511						514
Current regulatory assets			149						66
Other current assets			70						63
Total current assets			1,475						1,145
Property, Plant, and Equipment, Net			20,083						18,788
Investments and Other Assets:
Nuclear decommissioning trust fund			1,502						1,342
Regulatory assets (includes $449 and $465 related to VIEs, respectively)			1,454						1,366
Pension and other postretirement benefits			202						211
Other assets			235						254
Total investments and other assets			3,393						3,173
TOTAL ASSETS			$	24,951					$	23,106
LIABILITIES AND SHAREHOLDERS’ EQUITY
Current Liabilities:
Current maturities of long-term debt (includes $29 and $17 related to VIEs, respectively)			$	29					$	17
Short-term debt			259						—
Borrowings from money pool			51						—
Accounts and wages payable			355						629
Accounts payable – affiliates			80						50
Taxes accrued			192						29
Interest accrued			94						88
Other current liabilities			204						206
Total current liabilities			1,264						1,019
Long-term Debt, Net (includes $437 and $448 related to VIEs, respectively)			8,130						7,671
Long-term Debt, Net - Related Parties			87						57
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes and tax credits, net			2,622						2,217
Regulatory liabilities			3,260						3,176
Asset retirement obligations			839						818
Other deferred credits and liabilities			166						150
Total deferred credits and other liabilities			6,887						6,361
Commitments and Contingencies (Notes 2, 8, 9, and 10)
Shareholders’ Equity:
Common stock, $5 par value, 150.0 shares authorized – 102.1 shares outstanding			511						511
Other paid-in capital, principally premium on common stock			3,201						3,201
Preferred stock			80						80
Retained earnings			4,791						4,206
Total shareholders’ equity			8,583						7,998
TOTAL LIABILITIES AND SHAREHOLDERS’ EQUITY			$	24,951					$	23,106

The accompanying notes as they relate to Ameren Missouri are an integral part of these consolidated financial statements.

UNION ELECTRIC COMPANY (d/b/a AMEREN MISSOURI)

CONSOLIDATED STATEMENT OF CASH FLOWS

(Unaudited) (In millions)

			Nine Months Ended September 30,
			2025						2024
Cash Flows From Operating Activities:
Net income			$	713					$	537
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization			673						641
Amortization of nuclear fuel			39						59
Amortization of debt issuance costs and premium/discounts			7						5
Deferred income taxes and tax credits, net			167						2
Allowance for equity funds used during construction			(37)						(38)
Other			7						69
Changes in assets and liabilities:
Receivables			(245)						(178)
Inventories			3						(21)
Accounts and wages payable			(240)						(223)
Taxes accrued			336						218
Regulatory assets and liabilities			(155)						(5)
Assets, other			21						(20)
Liabilities, other			26						10
Pension and other postretirement benefits			(42)						(59)
Net cash provided by operating activities			1,273						997
Cash Flows From Investing Activities:
Capital expenditures			(1,873)						(1,839)
Nuclear fuel expenditures			(20)						(57)
Purchases of securities – nuclear decommissioning trust fund			(373)						(499)
Sales and maturities of securities – nuclear decommissioning trust fund			348						480
Money pool advances, net			43						(9)
Other			—						(8)
Net cash used in investing activities			(1,875)						(1,932)
Cash Flows From Financing Activities:
Dividends on common stock			(125)						—
Dividends on preferred stock			(3)						(3)
Short-term debt, net			259						406
Money pool borrowings, net			51						(289)
Maturities of long-term debt			—						(350)
Issuances of long-term debt			500						846
Capital contribution from parent			—						350
Debt issuance costs			(4)						(10)
Other			—						(15)
Net cash provided by financing activities			678						935
Net change in cash, cash equivalents, and restricted cash			76						—
Cash, cash equivalents, and restricted cash at beginning of year			17						10
Cash, cash equivalents, and restricted cash at end of period			$	93					$	10

The accompanying notes as they relate to Ameren Missouri are an integral part of these consolidated financial statements.

UNION ELECTRIC COMPANY (d/b/a AMEREN MISSOURI)

CONSOLIDATED STATEMENT OF SHAREHOLDERS’ EQUITY

(Unaudited) (In millions)

			Three Months Ended September 30,												Nine Months Ended September 30,
			2025						2024						2025						2024
Common Stock			$	511					$	511					$	511					$	511
Other Paid-in Capital
Beginning of period			3,201						3,075						3,201						2,725
Capital contributions from parent			—						—						—						350
Other paid-in capital, end of period			3,201						3,075						3,201						3,075
Preferred Stock			80						80						80						80
Retained Earnings:
Beginning of period			4,348						3,800						4,206						3,647
Net income			519						382						713						537
Dividends on common stock			(75)						—						(125)						—
Dividends on preferred stock			(1)						(1)						(3)						(3)
Retained earnings, end of period			4,791						4,181						4,791						4,181
Total Shareholders’ Equity			$	8,583					$	7,847					$	8,583					$	7,847

The accompanying notes as they relate to Ameren Missouri are an integral part of these consolidated financial statements.

AMEREN ILLINOIS COMPANY (d/b/a AMEREN ILLINOIS)

STATEMENT OF INCOME

(Unaudited) (In millions)

			Three Months Ended September 30,												Nine Months Ended September 30,
			2025						2024						2025						2024
Operating Revenues:
Electric			$	829					$	672					$	2,203					$	1,899
Natural gas			117						121						686						660
Total operating revenues			946						793						2,889						2,559
Operating Expenses:
Purchased power			284						169						642						474
Natural gas purchased for resale			19						26						188						173
Other operations and maintenance			241						229						702						663
Depreciation and amortization			162						155						484						462
Taxes other than income taxes			38						37						126						116
Total operating expenses			744						616						2,142						1,888
Operating Income			202						177						747						671
Other Income, Net			30						37						101						105
Interest Charges			67						63						192						178
Income Before Income Taxes			165						151						656						598
Income Taxes			17						37						134						144
Net Income			148						114						522						454
Preferred Stock Dividends			—						—						1						1
Net Income Available to Common Shareholder			$	148					$	114					$	521					$	453

The accompanying notes as they relate to Ameren Illinois are an integral part of these financial statements.

AMEREN ILLINOIS COMPANY (d/b/a AMEREN ILLINOIS)

BALANCE SHEET

(Unaudited) (In millions)

			September 30, 2025						December 31, 2024
ASSETS
Current Assets:
Cash and cash equivalents			$	—					$	—
Advances to money pool			51						—
Accounts receivable – trade (less allowance for doubtful accounts of $23 and $18, respectively)			419						300
Accounts receivable – affiliates			21						15
Unbilled revenue			146						175
Miscellaneous accounts receivable			36						28
Inventories			289						244
Prepaid assets			65						59
Current regulatory assets			106						281
Other current assets			8						8
Total current assets			1,141						1,110
Property, Plant, and Equipment, Net			16,274						15,530
Investments and Other Assets:
Goodwill			411						411
Regulatory assets			1,124						1,011
Pension and other postretirement benefits			492						471
Other assets			756						697
Total investments and other assets			2,783						2,590
TOTAL ASSETS			$	20,198					$	19,230
LIABILITIES AND SHAREHOLDERS’ EQUITY
Current Liabilities:
Current maturities of long-term debt			$	—					$	300
Short-term debt			—						88
Borrowings from money pool			—						37
Accounts and wages payable			314						324
Accounts payable – affiliates			106						74
Interest accrued			59						59
Customer deposits			212						185
Purchase of receivables liabilities			55						43
Current regulatory liabilities			101						79
Other current liabilities			128						129
Total current liabilities			975						1,318
Long-term Debt, Net			6,253						5,549
Long-term Debt, Net – Related Parties			5						3
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes and tax credits, net			2,245						2,143
Regulatory liabilities			2,705						2,573
Other deferred credits and liabilities			308						273
Total deferred credits and other liabilities			5,258						4,989
Commitments and Contingencies (Notes 2, 8, and 9)
Shareholders’ Equity:
Common stock, no par value, 45.0 shares authorized – 25.5 shares outstanding			—						—
Other paid-in capital			3,056						3,056
Preferred stock			49						49
Retained earnings			4,602						4,266
Total shareholders’ equity			7,707						7,371
TOTAL LIABILITIES AND SHAREHOLDERS’ EQUITY			$	20,198					$	19,230

The accompanying notes as they relate to Ameren Illinois are an integral part of these financial statements.

AMEREN ILLINOIS COMPANY (d/b/a AMEREN ILLINOIS)

STATEMENT OF CASH FLOWS

(Unaudited) (In millions)

			Nine Months Ended September 30,
			2025						2024
Cash Flows From Operating Activities:
Net income			$	522					$	454
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization			484						461
Amortization of debt issuance costs and premium/discounts			3						3
Deferred income taxes and tax credits, net			30						72
Allowance for equity funds used during construction			(21)						(10)
Other			24						32
Changes in assets and liabilities:
Receivables			(129)						(23)
Inventories			(45)						(35)
Accounts and wages payable			(1)						(8)
Taxes accrued			26						118
Regulatory assets and liabilities			255						96
Assets, other			(49)						(32)
Liabilities, other			68						5
Pension and other postretirement benefits			(50)						(66)
Net cash provided by operating activities			1,117						1,067
Cash Flows From Investing Activities:
Capital expenditures			(1,127)						(1,091)
Money pool advances, net			(51)						—
Other			(3)						1
Net cash used in investing activities			(1,181)						(1,090)
Cash Flows From Financing Activities:
Dividends on common stock			(185)						(50)
Dividends on preferred stock			(1)						(1)
Short-term debt, net			(88)						(349)
Money pool borrowings, net			(37)						(135)
Maturities of long-term debt			(300)						—
Issuances of long-term debt			711						624
Debt issuance costs			(8)						(7)
Net cash provided by financing activities			92						82
Net change in cash, cash equivalents, and restricted cash			28						59
Cash, cash equivalents, and restricted cash at beginning of year			302						234
Cash, cash equivalents, and restricted cash at end of period			$	330					$	293

The accompanying notes as they relate to Ameren Illinois are an integral part of these financial statements.

AMEREN ILLINOIS COMPANY (d/b/a AMEREN ILLINOIS)

STATEMENT OF SHAREHOLDERS’ EQUITY

(Unaudited) (In millions)

			Three Months Ended September 30,												Nine Months Ended September 30,
			2025						2024						2025						2024
Common Stock			$	—					$	—					$	—					$	—
Other Paid-in Capital			3,056						3,020						3,056						3,020
Preferred Stock			49						49						49						49
Retained Earnings:
Beginning of period			4,564						4,070						4,266						3,756
Net income			148						114						522						454
Dividends on common stock			(110)						(25)						(185)						(50)
Dividends on preferred stock			—						—						(1)						(1)
Retained earnings, end of period			4,602						4,159						4,602						4,159
Total Shareholders’ Equity			$	7,707					$	7,228					$	7,707					$	7,228

The accompanying notes as they relate to Ameren Illinois are an integral part of these financial statements.

AMEREN CORPORATION (Consolidated)

UNION ELECTRIC COMPANY (Consolidated) (d/b/a Ameren Missouri)

AMEREN ILLINOIS COMPANY (d/b/a Ameren Illinois)

COMBINED NOTES TO FINANCIAL STATEMENTS

(Unaudited)

September 30, 2025

NOTE 1 – 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. 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.

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.

Our accounting policies conform to GAAP. Our financial statements reflect all adjustments (which include normal, recurring adjustments) that are necessary, in our opinion, for a fair statement of our results. The preparation of financial statements in conformity with GAAP requires management to make certain estimates and assumptions. Such estimates and assumptions affect reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the dates of financial statements, and the reported amounts of revenues and expenses during the reported periods. Actual results could differ from those estimates. The results of operations for an interim period may not give a true indication of results that may be expected for a full year. These financial statements contained in this Form 10-Q should be read in conjunction with the financial statements and accompanying notes included in the Form 10-K.

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 September 30, 2025 and December 31, 2024:

						2025						2024
Unbilled revenue(a)						$	4					$	—
Other current assets(a)(b)						46						2
Noncurrent regulatory assets(a)						449						465
Current maturities of long-term debt(c)						29						17
Interest accrued(c)						18						1
Current regulatory liabilities(d)						15						—
Long-term debt, net(c)						437						448

(a)Assets may be used only to meet AMF’s obligations and commitments.

(b)Included in “Restricted cash” on Ameren Missouri’s balance sheet.

(c)The securitized tariff bondholders have no recourse to Ameren Missouri.

(d)Included in “Other current liabilities” on Ameren Missouri’s balance sheet.

Variable Interest Entities that are Not Consolidated

As of September 30, 2025, and December 31, 2024, Ameren had unconsolidated variable interests in various equity method investments, primarily to advance innovative energy technologies, totaling $60 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 September 30, 2025, Ameren’s maximum exposure to loss related to these variable interest entities is limited to the investment in these partnerships of $60 million plus associated outstanding funding commitments of $31 million.

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. As of September 30, 2025, the cash surrender value of COLI at Ameren and Ameren Illinois was $220 million (December 31, 2024 – $260 million) and $124 million (December 31, 2024 – $118 million), respectively, while total borrowings against the policies were $117 million (December 31, 2024 – $110 million) at both Ameren and Ameren Illinois. Ameren and Ameren Illinois have the right to offset the borrowings against the cash surrender value of the policies and, consequently, present the net asset in “Other assets” on their respective balance sheets. The net cash surrender value of Ameren’s COLI is affected by the investment performance of a separate account in which Ameren holds a beneficial interest.

Accounting and Reporting Developments

Improvements to the Accounting for Internal-Use Software

In September 2025, the FASB issued authoritative guidance that made targeted improvements to the accounting for internal-use software. The guidance requires an entity to capitalize internal-use software costs when management has authorized and committed to funding the software project, and it is probable that the project will be completed and the software will be used to perform its intended function. This guidance will be effective for the Ameren Companies in the first quarter of 2028. We are currently assessing the impacts of this guidance on our results of operations, financial position, and liquidity.

NOTE 2 – RATE AND REGULATORY MATTERS

Below is a summary of updates to significant regulatory proceedings and related legal proceedings. See Note 2 – Rate and Regulatory Matters under Part II, Item 8, of the Form 10-K for additional information and a summary of our regulatory frameworks. We are unable to predict the ultimate outcome of these matters, the timing of final decisions of the various agencies and courts, or the impact on our results of operations, financial position, or liquidity.

Missouri

Missouri Senate Bill 4

In April 2025, Missouri Senate Bill 4 was enacted and became effective in August 2025. The law includes certain provisions that affect the regulation of Ameren Missouri’s electric and natural gas businesses. These provisions create modifications to the PISA and integrated

resource planning, require electric utilities to submit service tariff schedules for high-demand customers, allow the MoPSC to authorize inclusion of construction work in progress in rate base for new natural gas-fired generation facilities and new generation facilities approved through integrated resource planning, and allow natural gas utilities to file regulatory rate reviews using a future test year, among other things.

Pursuant to the law, the PISA has been modified to include new natural gas generating units placed in service after the effective date of the law as qualifying property, plant, and equipment eligible for deferral and recovery of 85% of the related depreciation expense. These new natural gas generating units will also be included in the 85% of rate base allowed to earn a return at the applicable WACC under the PISA. The law also reduced the annual limit on increases to the electric service revenue requirement used to set customer rates, compared to the revenue requirement established in the immediately preceding rate order, due to the inclusion of incremental PISA deferrals in the revenue requirement. The annual limit in effect was 2.5% and changed to 2.25%, prorated monthly, for revenue requirements approved by the MoPSC after August 2025. Furthermore, the PISA's effective date has been extended through 2035, unless Ameren Missouri requests and receives MoPSC approval of an extension through 2040.

The law also requires an electric utility to develop and submit to the MoPSC schedules that include its service tariff applicable to customers projected to have 100 MWs or more of demand. These schedules must reasonably ensure that such high-demand customers’ rates reflect a representative share of the costs incurred to serve them and further, must prevent other lower-demand customer rates from reflecting any unjust or unreasonable costs arising from service provided to these high-demand customers.

In addition, the law made modifications to integrated resource planning, which requires Missouri electric utilities to file plans for meeting their customers' long-term energy needs. By August 2027, the MoPSC will publish a schedule for Missouri electric utilities to file integrated resource plans every four years. The MoPSC will be required to issue an order on the plans and shall determine whether the electric utility has submitted sufficient documentation and selected preferred resource plans representing a reasonable and prudent means of serving the utility's load obligations at just and reasonable rates. In making this determination, the MoPSC shall consider whether the plans appropriately balance specific factors described in the law. If the MoPSC approves the plans, requests for CCNs for new generation facilities to be constructed or acquired as a part of the approved plans shall be deemed necessary and convenient and the scope of the CCN proceedings to review projects will be limited. The approved generation facilities will also be eligible to include construction work in progress in rate base, subject to MoPSC approval, which would improve the timeliness of cash recovery. Utilities are not allowed to capitalize allowance for funds used during construction on amounts included in rate base under this provision. The amount of construction work in progress to be included in rate base is limited to prudently incurred expenditures made within the construction period for the facility.

Further, outside of the integrated resource planning process discussed above, the law allows a Missouri electric utility to request that the MoPSC authorize the inclusion of construction work in progress for new natural gas-fired generation facilities in rate base. Under this provision, utilities are not allowed to capitalize allowance for funds used during construction on projects approved to include construction work in progress in rate base. The amount of construction work in progress to be included in rate base is limited to prudently incurred expenditures made within the construction period for the facility. The provisions allowing for the inclusion of construction work in progress on natural gas-fired generation in rate base expire in December 2035, unless Ameren Missouri requests and receives MoPSC approval of an extension through 2045.

Also, beginning in July 2026 the law allows natural gas utilities to file regulatory rate reviews using a future test year, subject to MoPSC approval. If a natural gas utility is allowed to use a future test year, a reconciliation of the actual rate base and certain forecasted costs will be performed 45 days after the end of the test year. If a given year’s actual revenue requirement is less than the revenue requirement approved by the MoPSC due to changes in rate base or certain other costs, an adjustment is made to reduce natural gas operating revenues with an offset to a regulatory liability to reflect that test year’s amounts. The regulatory liability will then be refunded to customers in the next regulatory rate review and will accrue carrying costs at the applicable WACC.

April 2025 MoPSC Electric Rate Order

In April 2025, the MoPSC issued an order in Ameren Missouri’s 2024 electric service regulatory rate review, approving nonunanimous stipulations and agreements. The order authorizes an increase of $355 million to Ameren Missouri’s annual revenue requirement for electric retail service, effective June 1, 2025. The approved revenue requirement was based on infrastructure investments as of December 31, 2024. The order did not explicitly specify an ROE, capital structure, rate base, or any rate base disallowances. The order provides for the continued use of all existing riders and trackers. The order also changed annualized depreciation, regulatory asset and liability amortization amounts, and the base level of expenses for trackers. On an annualized basis, these changes reflect an increase in “Depreciation and amortization” of approximately $70 million, among other expense changes, on Ameren’s and Ameren Missouri’s consolidated statements of income.

2024 Natural Gas Delivery Service Regulatory Rate Order

In July 2025, the MoPSC issued an order in Ameren Missouri’s 2024 natural gas delivery service regulatory rate review, approving a unanimous stipulation and agreement. The order authorizes an increase of $32 million to Ameren Missouri’s annual revenue requirement for

natural gas delivery service, effective September 1, 2025. The order did not explicitly specify an ROE, capital structure, rate base, or any rate base disallowances. The order provides for the continued use of all of Ameren Missouri’s existing riders and trackers.

Large Load Customer Rate Plan

In November 2025, Ameren Missouri updated its May 2025 request with the MoPSC to modify its existing large primary service tariff to require customers requesting 75 MWs or more of demand and who are served at transmission level voltage to comply with additional tariff terms. The additional terms include a service term of 12 years plus a ramp period of up to five years to reach peak demand, minimum demand charges of 80% of contracted capacity, customer exit terms and fees, and customer credit and collateral requirements, among other terms. In addition, new customer programs would be available under this tariff, which allow customers to support renewable generation, battery storage, and/or nuclear generation through incremental payments. A decision by the MoPSC is expected by February 2026.

Generation and Storage Facilities

Ameren Missouri is party to agreements to acquire and/or construct various generation and storage facilities that are consistent with the 2025 Change to the 2023 PRP. The generation and storage facilities are eligible for recovery under the PISA. The following table provides information with respect to each facility:

			Agreement type			Facility size			Status of MoPSC CCN						In-service date**(a)**
Vandalia Solar Project(b)			Self-build			50-MW			Approved March 2024						Fourth quarter 2025
Bowling Green Solar Project(b)			Self-build			50-MW			Approved March 2024						First quarter 2026
Split Rail Solar Project(b)			Build-transfer(c)			300-MW			Approved March 2024						Mid-2026
Castle Bluff Natural Gas Project(d)			Self-build			800-MW			Approved October 2024						Fourth quarter 2027
Big Hollow Battery Energy Storage Project			Self-build			400-MW			Filed June 2025(e)						Second quarter 2028
Big Hollow Natural Gas Project			Self-build			800-MW			Filed June 2025(e)						Third quarter 2028
Reform Solar Project			Self-build			250-MW			Filed August 2025(e)						Fourth quarter 2028

(a)In-service dates are dependent on the timing of regulatory approvals and construction completion, among other things.

(b)These projects collectively represent approximately $0.8 billion of capital expenditures.

(c)FERC approval of acquisition received November 2024.

(d)This project represents approximately $0.9 billion of capital expenditures.

(e)Ameren Missouri expects a decision by the MoPSC in the first half of 2026.

MISO Long-Range Transmission Projects CCN

In 2022, the MISO approved the first tranche of projects related to a preliminary long-range transmission planning roadmap of projects through 2039. A portion of these projects were assigned or awarded via a competitive bid process to various utilities, including Ameren. In 2024, ATXI filed requests for CCNs, among other things, with the MoPSC related to the MISO long-range transmission projects that it expects to construct within the MoPSC’s jurisdiction. In July 2025, the MoPSC issued an order approving a CCN for a portion of the projects and a decision on the remaining projects is expected in 2025.

Illinois

MYRP

In December 2024, the ICC issued an order in connection with a revised Grid Plan and a revised MYRP filed by Ameren Illinois in March 2024, approving revenue requirements for electric distribution services for 2024 through 2027 of $1,206 million, $1,287 million, $1,367 million, and $1,421 million, respectively. Using the 2023 revenue requirement as a starting point, the approved revenue requirements in the ICC’s December 2024 order represent a cumulative four-year increase of $308 million. Rate changes consistent with the December 2024 order became effective in December 2024. In March 2025, Ameren Illinois filed an appeal of the ICC’s December 2024 order to the Illinois Appellate Court for the Fifth Judicial District to revise the allowed ROE and to include an asset associated with other postretirement benefits in the rate base, among other things. In addition, Ameren Illinois filed an appeal related to orders issued by the ICC in December 2023 and June 2024 related to the MYRP proceeding. The appellate court is under no deadline to address the appeals, and Ameren Illinois cannot predict the ultimate outcome of the appeals.

2024 Electric Distribution Service Revenue Requirement Reconciliation Adjustment

In April 2025, Ameren Illinois filed for a reconciliation adjustment to its 2024 electric distribution service revenue requirement with the ICC. In September 2025, Ameren Illinois filed a revised reconciliation adjustment, requesting recovery of $60 million. The adjustment reflects Ameren Illinois’ actual 2024 recoverable costs, 2024 year-end rate base, and a capital structure composed of 50% common equity. In September 2025, the ICC staff submitted its calculation of the reconciliation adjustment, recommending recovery of $47 million. The ICC staff’s recommendation excluded an asset associated with other postretirement benefits from the rate base. An ICC decision in this proceeding is required by December 2025, and any approved adjustment would be collected from customers in 2026.

Electric Customer Energy-Efficiency Investments

In May 2025, Ameren Illinois filed its annual electric energy-efficiency formula rate update to increase its annual revenues by $12 million with the ICC. In August 2025, the ICC staff filed a recommendation supporting Ameren Illinois’ requested increase. An ICC decision in this proceeding is required by December 2025, with new rates effective in January 2026.

Electric Energy Efficiency Plan

In August 2025, the ICC issued an order approving Ameren Illinois’ energy-efficiency plan that includes annual investments in electric energy-efficiency programs of approximately $126 million per year from 2026 through 2029. The ICC has the ability to reduce the amount of electric energy-efficiency savings goals in future program years if there are insufficient cost-effective programs available, which could reduce the investments in electric energy-efficiency programs.

2025 Natural Gas Delivery Service Rate Review

In January 2025, Ameren Illinois filed a request with the ICC seeking approval to increase its annual revenues for natural gas delivery service. In July 2025, Ameren Illinois filed a revised request seeking to increase its annual revenues by $135 million. The request is based on a 10.7% ROE, a capital structure composed of 52% common equity, and a rate base of $3.3 billion. Ameren Illinois used a 2026 future test year in this proceeding. In August 2025, the ICC staff filed a revised recommendation to increase Ameren Illinois’ annual revenues for natural gas delivery service by $104 million. The recommendation is based on a 9.93% ROE, a capital structure composed of 50% common equity, and a rate base of $3.2 billion. In addition, in August 2025, the Illinois Attorney General's office recommended an increase to annual revenues for natural gas delivery service of $55 million, based on a 9.45% ROE, a capital structure composed of 50% common equity, and a rate base of $3.0 billion. In October 2025, the administrative law judge issued a proposed order for an increase to annual revenues of $91 million. The order was consistent with the ICC staff’s recommendation with the exception of the exclusion of the non-service cost component of the net periodic benefit income related to other postretirement benefits in the annual revenue requirement. A decision by the ICC in this proceeding is required by early December 2025, with new rates expected to be effective in early December 2025. Ameren Illinois cannot predict the level of any delivery service rate change the ICC may approve, nor whether any rate change that may eventually be approved will be sufficient to enable Ameren Illinois to recover its costs and to earn a reasonable return on investments when the rate changes go into effect.

MISO Long-Range Transmission Projects CCN

In 2022, the MISO approved the first tranche of projects related to a preliminary long-range transmission planning roadmap of projects through 2039. A portion of these projects were assigned or awarded via a competitive bidding process to various utilities, including Ameren. In July 2025, the ICC issued an order approving a request filed by Ameren Illinois and ATXI for a CCN, among other things, related to the portion of the MISO long-range transmission projects they will construct within the ICC’s jurisdiction.

Federal

MISO Transmission Rate Incentives

In 2024, the MISO approved a first set of second tranche projects related to its preliminary long-range transmission planning roadmap of projects through 2039. A portion of these projects were assigned to Ameren and are estimated to cost approximately $1.3 billion, based on the MISO’s cost estimate. In July 2025, the FERC approved transmission rate incentives relating to the second tranche projects assigned to Ameren. The incentives will allow construction work in progress to be included in rate base for projects constructed by ATXI, thereby improving the timeliness of cash recovery, and would allow recovery of prudently incurred costs, subject to FERC approval, for any portion of the projects if they are abandoned for reasons beyond the control of Ameren. ATXI will not capitalize allowance for funds used during construction on the related projects.

FERC ROE Complaint Cases

Since November 2013, the allowed base ROE for FERC-regulated transmission rate base under the MISO tariff has been subject to customer complaint cases and has been changed by various FERC orders. In October 2024, the FERC issued an order, which decreased the allowed base ROE from 10.02% to 9.98% and required refunds, with interest, for the periods from November 2013 to February 2015 and from late September 2016 forward. In January 2025, the MISO transmission owners, including Ameren Missouri, Ameren Illinois, and ATXI, filed an appeal of the October 2024 order to the United States Court of Appeals for the District of Columbia Circuit. In March 2025, the FERC issued an order rejecting all rehearing requests of the October 2024 order. In April 2025, the MISO transmission owners, including Ameren Missouri, Ameren Illinois, and ATXI, filed an appeal of the March 2025 order to the United States Court of Appeals for the District of Columbia Circuit.

As of September 30, 2025, Ameren and Ameren Illinois had recorded liabilities in "Current regulatory liabilities" on their balance sheets of $7 million and $4 million, respectively, to reflect the expected refunds, including interest, associated with the allowed base ROE set by the October 2024 order.

NOTE 3 – SHORT-TERM DEBT AND LIQUIDITY

The liquidity needs of the Ameren Companies are supported through the use of available cash, drawings under committed credit agreements, commercial paper issuances, and, in the case of Ameren Missouri and Ameren Illinois, short-term affiliate borrowings. See Note 4 – Short-term Debt and Liquidity under Part II, Item 8, of the Form 10-K for a description of our indebtedness provisions and other covenants as well as a description of money pool agreements.

Short-term Borrowings

The Missouri Credit Agreement and the Illinois Credit Agreement are available to support issuances under Ameren (parent)’s, Ameren Missouri’s, and Ameren Illinois’ commercial paper programs, respectively, subject to borrowing sublimits, and to support the issuance of letters of credit. As of September 30, 2025, based on commercial paper outstanding and letters of credit issued under the Credit Agreements, along with cash and cash equivalents, the net liquidity available to Ameren (parent), Ameren Missouri, and Ameren Illinois, collectively, was $1.6 billion. The Ameren Companies were in compliance with the covenants in their Credit Agreements as of September 30, 2025. As of September 30, 2025, the ratios of consolidated indebtedness to consolidated total capitalization, calculated in accordance with the provisions of the Credit Agreements, were 61%, 49%, and 45% for Ameren, Ameren Missouri, and Ameren Illinois, respectively.

The following table presents commercial paper outstanding, net of issuance discounts, as of September 30, 2025, and December 31, 2024. There were no borrowings outstanding under the Credit Agreements as of September 30, 2025, or December 31, 2024.

			September 30, 2025									December 31, 2024
Ameren (parent)			$	644								$	1,055
Ameren Missouri			259									—
Ameren Illinois			—									88
Ameren consolidated			$	903								$	1,143

The following table summarizes the activity and relevant interest rates for Ameren (parent)’s, Ameren Missouri’s, and Ameren Illinois’ commercial paper issuances under the Credit Agreements for the nine months ended September 30, 2025 and 2024:

						Ameren (parent)						Ameren Missouri						Ameren Illinois						Ameren Consolidated
2025
Average daily amount outstanding						$	637					$	245					$	130					$	1,012
Weighted-average interest rate						4.60		%				4.58		%				4.55		%				4.59		%
Peak amount outstanding during period(a)						$	1,139					$	650					$	425					$	1,603
Peak interest rate						4.75		%				4.72		%				4.70		%				4.75		%
2024
Average daily amount outstanding						$	177					$	187					$	256					$	620
Weighted-average interest rate						5.46		%				5.52		%				5.57		%				5.53		%
Peak amount outstanding during period(a)						$	948					$	576					$	694					$	1,542
Peak interest rate						5.60		%				5.68		%				5.68		%				5.68		%

(a)The timing of peak outstanding commercial paper issuances under the Credit Agreements varies by company. Therefore, the sum of individual company peak amounts may not equal the Ameren consolidated peak amount for the period.

Money Pools

Ameren has money pool agreements with and among its subsidiaries to coordinate and provide for certain short-term cash and working capital requirements. The average interest rate for borrowings under the utility money pool for the three and nine months ended September 30, 2025, was 4.53% and 4.56%, respectively (2024 – 5.29% and 5.37%). See Note 8 – Related-party Transactions for the amount of interest income and expense from the utility money pool agreements recorded by Ameren Missouri and Ameren Illinois for the three and nine months ended September 30, 2025 and 2024.

NOTE 4 – LONG-TERM DEBT AND EQUITY FINANCINGS

Ameren

For the three and nine months ended September 30, 2025, Ameren issued a total of 0.1 million and 0.3 million shares of common stock, under its DRPlus and 401(k) plan, and received proceeds of $3 million and $28 million. As of September 30, 2025, Ameren had a receivable of $7 million related to issuances of common stock under its DRPlus and 401(k) plan. In addition, in the first quarter of 2025, Ameren issued 0.3 million shares of common stock valued at $25 million upon the settlement of stock-based compensation awards.

Ameren has entered into an equity distribution sales agreement pursuant to which Ameren may offer and sell from time to time its common stock through an ATM program, which includes the ability to enter into forward sale agreements. In August 2025, Ameren increased the amount of common stock available for sale under the ATM program by $1.25 billion to a total of $3 billion. There were no shares issued under the ATM program during the three and nine months ended September 30, 2025. As of September 30, 2025, Ameren had approximately $1.5 billion of common stock remaining available for sale under the ATM program.

Forward sale agreements outstanding as of September 30, 2025 under the ATM program for 5.8 million shares, can be settled at Ameren’s discretion on or prior to dates ranging from January 23, 2026, to March 6, 2026. The initial forward sale price for the agreements ranged from $81.00 to $98.66, with an average initial forward sale price of $91.02. Additionally in May 2025, Ameren entered into forward sale agreements separate from the ATM program with multiple counterparties relating to 6.4 million shares of common stock. The forward sale agreements can be settled at Ameren’s discretion on or prior to January 15, 2027, and the initial forward sale price under these agreements was $91.89 per share. On a settlement date or dates, if Ameren elects to physically settle a forward sale agreement, Ameren will issue shares of common stock to the counterparties at the then-applicable forward sale price. Each initial forward sale price is subject to adjustment based on a floating interest rate factor equal to the overnight bank funding rate less a spread of 75 basis points, and will be subject to decrease on certain dates specified in the forward sale agreements by specified amounts related to expected dividends on shares of the common stock during the term of the forward sale agreements. If the overnight bank funding rate is less than or more than the spread on any day, the interest rate factor will result in a reduction or an increase, respectively, of the forward sale price. The forward sale agreements will be physically settled unless Ameren elects to settle in cash or to net share settle.

At September 30, 2025, Ameren could have settled the forward sale agreements with physical delivery of 12.2 million shares of common stock to the respective counterparties in exchange for cash of $1.1 billion. Alternatively, the forward sale agreements could have also been net settled at September 30, 2025, with delivery of approximately $158 million of cash or approximately 1.5 million shares of common stock to the counterparties. In connection with the forward sale agreements outstanding at September 30, 2025, the various counterparties, or their affiliates, borrowed from third parties and sold 12.2 million shares of common stock. The gross sales price of these shares totaled $1.1 billion. Ameren does not receive any proceeds from such sales of borrowed shares. The forward sale agreements have been classified as equity transactions.

In March 2025, Ameren (parent) issued $750 million of 5.375% senior unsecured notes due March 2035, with interest payable semiannually on March 15 and September 15 of each year, beginning September 15, 2025. Net proceeds from this issuance were used for general corporate purposes, including the repayment of short-term debt.

In June 2025, Ameren (parent) purchased senior secured notes and first mortgage bonds issued by Ameren Missouri and first mortgage bonds issued by Ameren Illinois for $24 million in the aggregate. On a consolidated basis, Ameren (parent)’s repurchase of these senior secured notes and first mortgage bonds were accounted for as a debt extinguishment and resulted in a pre-tax gain of $8 million, which is reflected in “Other Income, Net” on Ameren’s consolidated statement of income. Interest expense related to repurchased bonds was $1 million and $2 million for the three and nine months ended September 30, 2025.

Ameren Missouri

In April 2025, Ameren Missouri issued $500 million of 5.25% first mortgage bonds due April 2035, with interest payable semiannually on April 15 and October 15 of each year, beginning October 15, 2025. Net proceeds from this issuance were used to repay short-term debt.

Ameren Illinois

In March and September 2025, Ameren Illinois issued $350 million and $350 million, respectively, of 5.625% first mortgage bonds due March 2055, with interest payable semiannually on March 1 and September 1 of each year, beginning September 1, 2025 and March 1, 2026, respectively. Net proceeds from the March 2025 issuance were used to repay $300 million principal amount of its 3.25% senior secured notes that matured in March 2025, and net proceeds of both issuances were used to repay a portion of its short-term debt.

Indenture Provisions and Other Covenants

See Note 5 – Long-term Debt and Equity Financings under Part II, Item 8, of the Form 10-K for a description of our indenture provisions and other covenants, as well as restrictions on the payment of dividends. At September 30, 2025, the Ameren Companies were in compliance with the provisions and covenants contained in their indentures and articles of incorporation, as applicable, and ATXI was in compliance with the provisions and covenants contained in its note purchase agreements.

Off-balance-sheet Arrangements

At September 30, 2025, none of the Ameren Companies had any material off-balance-sheet financing arrangements, other than their investment in unconsolidated variable interest entities, letters of credit, and the multiple forward sale agreements relating to common stock. See Note 1 – Summary of Significant Accounting Policies for further detail concerning variable interest entities.

NOTE 5 – OTHER INCOME, NET

The following table presents the components of “Other Income, Net” in the Ameren Companies’ statements of income for the three and nine months ended September 30, 2025 and 2024:

			Three Months												Nine Months
			2025						2024						2025						2024
Ameren:
Allowance for equity funds used during construction			$	21					$	23					$	60					$	48
Other interest income			10						8						31						29
Non-service cost components of net periodic benefit income(a)			59						76						187						228
Miscellaneous income			6						—						13						6
Gain on the extinguishment of debt(b)			—						—						8						—
Losses related to equity method investments			(9)						(2)						(19)						(1)
Donations			(6)						(1)						(9)						(5)
Miscellaneous expense			(5)						(3)						(14)						(12)
Total Other Income, Net			$	76					$	101					$	257					$	293
Ameren Missouri:
Allowance for equity funds used during construction			$	14					$	15					$	37					$	38
Other interest income			3						2						7						7
Non-service cost components of net periodic benefit income(a)			29						35						96						104
Miscellaneous income			4						1						6						3
Donations			(2)						—						(4)						(2)
Miscellaneous expense			(3)						(2)						(7)						(6)
Total Other Income, Net			$	45					$	51					$	135					$	144
Ameren Illinois:
Allowance for equity funds used during construction			$	6					$	8					$	21					$	10
Other interest income			7						7						24						22
Non-service cost components of net periodic benefit income			21						25						61						78
Miscellaneous income			2						—						7						3
Donations			(4)						—						(5)						(2)
Miscellaneous expense			(2)						(3)						(7)						(6)
Total Other Income, Net			$	30					$	37					$	101					$	105

(a)For the three and nine months ended September 30, 2025, the non-service cost components of net periodic benefit income were adjusted by amounts deferred of $(9) million and $(41) million, respectively, due to a regulatory tracking mechanism for the difference between the level of such costs incurred by Ameren Missouri under GAAP and the level of such costs included in rates. The deferral was $(11) million and $(31) million, respectively, for the three and nine months ended September 30, 2024. See Note 11 – Retirement Benefits for additional information.

(b)See Note 4 – Long-term Debt and Equity Financings for additional information on 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.

NOTE 6 – DERIVATIVE FINANCIAL INSTRUMENTS

We use derivatives to manage the risk of changes in market prices for natural gas, power, and interest rates, as well as the risk of changes in rail transportation surcharges through fuel oil hedges. Such price fluctuations may cause the following:

• an unrealized appreciation or depreciation of our contracted commitments to purchase or sell when purchase or sale prices under the commitments are compared with current commodity prices;

• market values of natural gas inventories that differ from the cost of this commodity in inventory;

• actual cash outlays for interest expense and the purchase of commodities that differ from anticipated cash outlays; and

• actual off-system sales revenues that differ from anticipated revenues.

The derivatives that we use to hedge these risks are governed by our risk management policies for forward contracts, futures, options, and swaps. Our net positions are continually assessed within our structured hedging programs to determine whether new or offsetting transactions are required. The goal of the hedging ‘program is generally to mitigate financial risks while ensuring that sufficient volumes are available to meet our requirements. Contracts we enter into as part of our risk management program may be settled financially, settled by physical delivery, or net settled with the counterparty.

All contracts considered to be derivative instruments are required to be recorded on the balance sheet at their fair values, unless the NPNS exception applies. Many of our physical contracts, such as our purchased power contracts, qualify for the NPNS exception to derivative accounting rules. The revenue or expense on NPNS contracts is recognized at the contract price upon physical delivery. The following disclosures exclude NPNS contracts and other non-derivative commodity contracts that are accounted for under the accrual method of accounting.

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. As of September 30, 2025, and December 31, 2024, all commodity contracts that met the definition of a derivative and were not eligible for the NPNS exception received regulatory deferral. Interest rate hedges entered into by Ameren (parent) and discussed below do not receive regulatory deferral and were included in accumulated OCI as Ameren (parent) is not a rate-regulated entity. The cash flows from our derivative financial instruments follow the cash flow classification of the hedged item.

Ameren (parent) entered into interest rate swaps to hedge a portion of its interest rate risk on cash flows related to certain forecasted debt issuances to occur in 2026 and 2027. The interest rate swaps are designated as cash flow hedges and the corresponding changes in fair value each period are initially recorded on the balance sheet in “Accumulated other comprehensive loss” and reclassified into earnings when the debt is issued and the corresponding interest payments affect earnings during the debt term. As of September 30, 2025, and December 31, 2024, Ameren had interest rate swaps with notional amounts of $660 million and $140 million, respectively. Ameren recorded an unrealized loss, net of income tax benefits, on the change in fair value of interest rate swaps of less than $1 million and $6 million to "Accumulated other comprehensive loss" for the three and nine months ended September 30, 2025.

The following table presents open gross commodity contract volumes by commodity type for derivative assets and liabilities as of September 30, 2025, and December 31, 2024. As of September 30, 2025, these contracts extended through October 2028, October 2031 and May 2032 for fuel oils, natural gas, and power, respectively.

			Quantity (in millions, except as indicated)
			September 30, 2025									December 31, 2024
Commodity			Ameren Missouri			Ameren Illinois			Ameren			Ameren Missouri			Ameren Illinois			Ameren
Fuel oils (in gallons)			23			—			23			23			—			23
Natural gas (in MMBtu)			50			211			261			45			213			258
Power (in MWhs)			—			4			4			—			4			4

The following table presents the carrying value and balance sheet location of all derivative commodity contracts, none of which were designated as hedging instruments because all qualify for regulatory deferral, as of September 30, 2025, and December 31, 2024:

									September 30, 2025																								December 31, 2024
			Balance Sheet Location						Ameren Missouri									Ameren Illinois									Ameren												Ameren Missouri									Ameren Illinois									Ameren
Natural gas			Other current assets						$	1								$	3								$	4											$	2								$	2								$	4
			Other assets						1									5									6												2									4									6
Power			Other current assets						22									—									22												6									—									6
			Total assets						$	24								$	8								$	32											$	10								$	6								$	16
Fuel oils			Other current liabilities						$	2								$	—								$	2											$	2								$	—								$	2
			Other deferred credits and liabilities						1									—									1												2									—									2
Natural gas			Other current liabilities						3									18									21												5									22									27
			Other deferred credits and liabilities						5									8									13												6									13									19
Power			Other current liabilities						1									10									11												—									10									10
			Other deferred credits and liabilities						—									52									52												—									43									43
			Total liabilities						$	12								$	88								$	100											$	15								$	88								$	103

The Ameren Companies elect to present the fair value amounts of derivative assets and derivative liabilities subject to an enforceable master netting arrangement or similar agreement at the gross amounts on the balance sheet. However, if the gross amounts recognized on the balance sheet were netted with derivative instruments and cash collateral received or posted, the net amounts would not be materially different from the gross amounts at September 30, 2025, and December 31, 2024.

Credit Risk

In determining our concentrations of credit risk related to derivative instruments, we review our individual counterparties and categorize each counterparty into groupings according to the primary business in which each engages. As of September 30, 2025, if counterparty groups were to fail completely to perform on contracts, the Ameren Companies’ maximum exposure related to derivative assets would have been immaterial with or without consideration of the application of master netting arrangements or similar agreements and collateral held.

Certain of our derivative instruments contain collateral provisions tied to the Ameren Companies’ credit ratings. If our credit ratings were downgraded below investment grade, or if a counterparty with reasonable grounds for uncertainty regarding our ability to satisfy an obligation requested adequate assurance of performance, additional collateral postings might be required. The additional collateral required is the net liability position allowed under master netting arrangements or similar agreements, assuming (1) the credit risk-related contingent features underlying these arrangements were triggered and (2) those counterparties with rights to do so requested collateral. As of September 30, 2025, the aggregate fair value of derivative instruments with credit risk-related contingent features in a gross liability position, the cash collateral posted, and the aggregate amount of additional collateral that counterparties could require were each immaterial to Ameren, Ameren Missouri, and Ameren Illinois.

NOTE 7 – 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 measured at fair value on a recurring basis as of September 30, 2025, and December 31, 2024:

						September 30, 2025																		December 31, 2024
						Level 1			Level 2			Level 3			Total									Level 1			Level 2			Level 3			Total
Assets:
Ameren Missouri
			Derivative assets – commodity contracts:
			Natural gas			$	—		$	2		$	—		$	2								$	—		$	4		$	—		$	4
			Power			—			—			22			22									—			—			6			6
			Total derivative assets – commodity contracts			$	—		$	2		$	22		$	24								$	—		$	4		$	6		$	10
			Nuclear decommissioning trust fund:
			Equity securities:
			U.S. large capitalization			$	1,001		$	—		$	—		$	1,001								$	911		$	—		$	—		$	911
			Debt securities:
			U.S. Treasury and agency securities			—			235			—			235									—			191			—			191
			Corporate bonds			—			174			—			174									—			145			—			145
			Other			—			84			—			84									—			86			—			86
			Total nuclear decommissioning trust fund			$	1,001		$	493		$	—		$	1,494		(a)						$	911		$	422		$	—		$	1,333		(a)
			Total Ameren Missouri			$	1,001		$	495		$	22		$	1,518								$	911		$	426		$	6		$	1,343
Ameren Illinois
			Derivative assets – commodity contracts:
			Natural gas			$	—		$	4		$	4		$	8								$	—		$	3		$	3		$	6
			Total Ameren Illinois			$	—		$	4		$	4		$	8								$	—		$	3		$	3		$	6
Ameren
			Derivative assets – commodity contracts(b)			$	—		$	6		$	26		$	32								$	—		$	7		$	9		$	16
			Nuclear decommissioning trust fund(c)			1,001			493			—			1,494			(a)						911			422			—			1,333			(a)
			Total Ameren			$	1,001		$	499		$	26		$	1,526								$	911		$	429		$	9		$	1,349
Liabilities:
Ameren Missouri
			Derivative liabilities – commodity contracts:
			Fuel oils			$	3		$	—		$	—		$	3								$	4		$	—		$	—		$	4
			Natural gas			—			8			—			8									—			11			—			11
			Power			—			—			1			1									—			—			—			—
			Total Ameren Missouri			$	3		$	8		$	1		$	12								$	4		$	11		$	—		$	15
Ameren Illinois
			Derivative liabilities – commodity contracts:
			Natural gas			$	1		$	22		$	3		$	26								$	1		$	28		$	6		$	35
			Power			—			—			62			62									—			—			53			53
			Total Ameren Illinois			$	1		$	22		$	65		$	88								$	1		$	28		$	59		$	88
Ameren
			Derivative liabilities – commodity contracts(b)			$	4		$	30		$	66		$	100								$	5		$	39		$	59		$	103

(a)Balance excludes $8 million and $9 million of cash and cash equivalents, receivables, payables, and accrued income, net, for September 30, 2025, and December 31, 2024, 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.

Level 3 fuel oils and natural gas derivative contract assets and liabilities measured at fair value on a recurring basis were immaterial for all periods presented. 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 nine months ended September 30, 2025 and 2024:

			2025															2024
			Ameren Missouri			Ameren Illinois									Ameren									Ameren Missouri			Ameren Illinois			Ameren
For the three months ended September 30:
Beginning balance at July 1			$	13		$	(76)								$	(63)								$	14		$	(61)		$	(47)
Realized and unrealized gains/(losses) included in regulatory assets/liabilities			12			12									24									(1)			(21)			(22)
Settlements			(4)			2									(2)									(3)			4			1
Ending balance at September 30			$	21		$	(62)								$	(41)								$	10		$	(78)		$	(68)
Change in unrealized gains/(losses) related to assets/liabilities held at September 30			$	11		$	11								$	22								$	(1)		$	(19)		$	(20)
For the nine months ended September 30:
Beginning balance at January 1			$	6		$	(53)								$	(47)								$	4		$	(68)		$	(64)
Realized and unrealized gains/(losses) included in regulatory assets/liabilities			28			(18)									10									13			(23)			(10)
Settlements			(13)			9									(4)									(7)			13			6
Ending balance at September 30			$	21		$	(62)								$	(41)								$	10		$	(78)		$	(68)
Change in unrealized gains/(losses) related to assets/liabilities held at September 30			$	21		$	(17)								$	4								$	10		$	(18)		$	(8)

All gains or losses related to our Level 3 derivative commodity contracts are expected to be collected or refunded through customer rates; therefore, there is no impact to either net income or other comprehensive income resulting from changes in the fair value of these instruments.

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 September 30, 2025, and December 31, 2024:

									Fair Value																		Weighted Average**(b)**
			Commodity						Assets						Liabilities			Valuation Technique(s)			Unobservable Input**(a)**			Range
2025			Power(c)			$			22			$			(63)			Discounted cash flow			Average forward peak and off-peak pricing – forwards/swaps ($/MWh)			33 – 67			43
																					Nodal basis ($/MWh)			(10) – 2			(5)
2024			Power(c)			$			6			$			(53)			Discounted cash flow			Average forward peak and off-peak pricing – forwards/swaps ($/MWh)			32 – 69			45
																					Nodal basis ($/MWh)			(8) – (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.

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 September 30, 2025, and December 31, 2024:

Long-Term Debt (Including Current Portion):			Carrying Amount**(a)**												Fair Value
									Level 2						Level 3						Total
			September 30, 2025
Ameren(b)			$	19,201											$	17,532					$	556		(c)			$	18,088
Ameren Missouri(d)			8,246												7,662						—						7,662
Ameren Illinois(d)			6,258												5,815						—						5,815
			December 31, 2024
Ameren(b)			$	17,579											$	15,395					$	538		(c)			$	15,933
Ameren Missouri(d)			7,745												6,926						—						6,926
Ameren Illinois(d)			5,852												5,243						—						5,243

(a)Included unamortized debt issuance costs, which were excluded from the fair value measurement, of $139 million, $63 million, and $56 million for Ameren, Ameren Missouri, and Ameren Illinois, respectively, as of September 30, 2025. Included unamortized debt issuance costs, which were excluded from the fair value measurement, of $129 million, $62 million, and $51 million for Ameren, Ameren Missouri, and Ameren Illinois, respectively, as of December 31, 2024.

(b)Amount excludes Ameren (parent)’s repurchase of Ameren Missouri’s senior secured notes and first mortgage bonds and Ameren Illinois’ first mortgage bonds.

(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).

The Ameren Companies’ carrying amounts of cash, cash equivalents, and restricted cash approximate fair value and are considered Level 1 in the fair value hierarchy. The Ameren Companies’ short-term borrowings approximate fair value because of the short-term nature of these instruments and are considered Level 2 in the fair value hierarchy.

NOTE 8 – 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 Ameren’s subsidiaries are reported as affiliate transactions on their individual financial statements, but those transactions are eliminated in consolidation for Ameren’s 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 Ameren’s 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 Missouri			Ameren Illinois									Ameren Missouri			Ameren Illinois
Income taxes payable to parent(a)			$	3		$	67								$	—		$	32
Income taxes receivable from parent(b)			2			—									28			—

(a)Included in “Accounts payable – affiliates” on the balance sheet.

(b)Included in “Accounts receivable – affiliates” on the balance sheet.

Effects of Related-party Transactions on the Statement of Income

The following table presents the impact on Ameren Missouri and Ameren Illinois of related-party transactions for the three and nine months ended September 30, 2025 and 2024:

												Three Months												Nine Months
Agreement			Income Statement Line Item									Ameren Missouri						Ameren Illinois						Ameren Missouri						Ameren Illinois
Ameren Missouri and Ameren Illinois			Operating Revenues			2025			$			8			$			(b)			$			23			$			1
rent and facility services						2024						8						(b)						23						(b)
Ameren Missouri and Ameren Illinois miscellaneous			Operating Revenues			2025			$			1			$			(b)			$			1			$			5
support services						2024						1						(b)						2						1
Total Operating Revenues						2025			$			9			$			(b)			$			24			$			6
						2024						9						(b)						25						1
Ameren Missouri and Ameren Illinois			Purchased Power			2025			$			2			$			1			$			7			$			2
transmission services from ATXI						2024						3						1						7						2
Ameren Missouri and Ameren Illinois			Other Operations and Maintenance			2025			$			(b)			$			(b)			$			(b)			$			3
rent and facility services						2024						(b)						(b)						(b)						(b)
Ameren Services support services			Other Operations and Maintenance			2025			$			42			$			39			$			130			$			119
agreement						2024						41						38						122						115
Total Other Operations and						2025			$			42			$			39			$			130			$			122
Maintenance						2024						41						38						122						115
Money pool interest			(Interest Charges)/Other Income, Net			2025			$			(b)			$			(b)			$			(b)			$			(b)
						2024						(b)						(b)						(3)						(2)
Long-term debt, net - related parties			(Interest Charges)			2025			$			(1)			$			(b)			$			(2)			$			(b)
						2024						—						—						—						—

(a)Not applicable.

(b)Amount less than $1 million.

NOTE 9 – 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 materials; establish siting and land use requirements; and protect against potential 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 use and handling of various chemicals or hazardous materials require release prevention plans and emergency response procedures.

Environmental regulations impact the electric utility industry and compliance obligations could be costly for Ameren Missouri, which operates coal-fired and natural gas-fired energy centers. Compliance obligations under the Clean Air Act stem from a variety of programs including the NSPS, the MATS, emission allowance programs, the CSAPR, and the National Ambient Air Quality Standards, which are subject to periodic review for certain pollutants. Collectively, these regulations cover a variety of pollutants, such as SO2, particulate matter, NOx, mercury, toxic metals and acid gases, and CO2 emissions. To the extent our operations impact surface water bodies, including wetlands, the Clean Water Act requires permitting as well as evaluation of the ecological and biological impact of those operations. Implementation of requirements under the Clean Air Act and the Clean Water Act typically occurs through the issuance of permits by state regulators or resource agencies, and capital expenditures associated with compliance could be significant. The management and disposal of coal ash from our coal-fired energy centers must comply with federal regulations known as the CCR Rule issued under the Resource Conservation and Recovery Act and require the closure of surface impoundments at our coal-fired energy centers along with groundwater monitoring requirements and the implementations of corrective measures if necessary. The combined effects of compliance with existing and future environmental regulations could result in significant capital expenditures, increased operating costs, and the potential for closure or alteration of operations at some of Ameren Missouri’s energy centers. Ameren and Ameren Missouri expect that such compliance costs would be recoverable through rates, subject to MoPSC prudence review, but the timing of costs and their recovery could be subject to regulatory lag.

Additionally, Ameren Missouri’s wind generation facilities may be subject to operating restrictions to limit the impact on protected species. Since 2021, Ameren Missouri’s High Prairie Energy Center has curtailed nighttime operations from April through October to limit impacts on protected species during the critical biological season. The extent and duration of future curtailments are currently unknown as assessment of mitigation technologies is ongoing. Ameren Missouri does not anticipate these operating curtailments will have a material impact on its results of operations, financial position, or liquidity.

Due to proposed rules issued by the EPA in June and July 2025, which are discussed below, Ameren and Ameren Missouri have revised capital expenditure estimates necessary to comply with environmental regulations to a range of $90 million to $120 million from 2025 through 2029. Additional capital expenditures beyond 2029 could be required. This estimate includes surface impoundment closure and corrective action measures required by the 2015 CCR Rule and modifications to cooling water intake structures at existing power plants under Clean Water Act rules in place prior to 2024, all of which are discussed below. The EPA could review and revise compliance requirements. In addition to planned retirements of coal-fired energy centers that were included in Ameren Missouri’s 2025 Change to the 2023 PRP and with respect to the Illinois emissions standards discussed in Note 14 – Commitments and Contingencies under Part II, Item 8, of the Form 10-K, Ameren Missouri’s current plan for compliance with existing air emission regulations includes burning low-sulfur coal and optimizing existing air pollution control equipment. Accordingly, the actual amount of capital expenditures required to comply with existing environmental regulations could vary from the above estimates because of uncertainty as to revisions to regulatory requirements by the EPA and/or state regulators and their timing and varying cost of potential compliance strategies, among other things.

The following sections describe the significant environmental statutes and regulations and environmental enforcement and remediation matters that affect or could affect our operations. The EPA could ultimately revise all or part of such regulations.

Clean Air Act

Federal and state laws, including the CSAPR, regulate emissions of SO2 and NOx through the reduction of emissions at their source and the use and retirement of emission allowances available for state budgets. In 2022, the EPA proposed the Good Neighbor Rule to reduce the transport of ozone from power plants by reducing the amount of CSAPR NOx allowances available for compliance. The EPA subsequently rejected state implementation plans proposed by Missouri and other states to comply with the Good Neighbor Rule. The disapprovals for some state implementation plans, including Missouri’s, were stayed by multiple appellate courts, and in 2024, the United States Supreme Court issued a stay of a federal implementation plan. In March 2025, the EPA announced it would take steps to repeal the Good Neighbor Rule and work with states on their implementation plans. Ameren Missouri complies with the current CSAPR requirements by minimizing emissions with low-sulfur coal, operation of two scrubbers at its Sioux Energy Center, and optimization of existing NOx air pollution control equipment. If the EPA repeals the currently stayed Good Neighbor Rule, Ameren Missouri would not expect additional NOx controls at its coal-fired energy centers to be necessary.

CO**2 Emissions Standards

In April 2024, the EPA issued a final rule that sets CO2 emission standards for existing coal-fired and new natural gas-fired power plants based on the emissions expected from adoption of carbon capture technology and/or natural gas co-firing for coal-fired power plants and carbon capture technology for new natural gas-fired power plants. Affected power plants are required to comply with the rule through a phased-in approach or retire. In June 2025, the EPA issued a proposed rule to repeal all greenhouse gas emissions standards for fossil fuel-fired power plants, including the April 2024 rule. In addition, in July 2025, the EPA announced a proposed rule reconsidering its 2009 Endangerment Finding for greenhouse gas emissions, which was the basis for implementing greenhouse gas emissions standards. The EPA expects to issue final rules by the end of 2025.

MATS

In April 2024, the EPA revised the MATS by establishing a more stringent standard for emissions of particulate matter, as well as requiring the use of continuous emissions monitoring systems. In April 2025, the presidential administration issued a proclamation through which it granted owners of coal-fired energy centers, including Ameren Missouri, a two-year extension of the compliance deadline. As such, the compliance deadline for the Labadie and Sioux energy centers is now set for July 2029. In June 2025, the EPA issued a proposed rule to repeal the April 2024 revisions to the MATS. The EPA expects to issue a final rule by the end of 2025.

NSPS

In November 2024, the EPA issued a proposed rule revising the NSPS to limit emissions of NOx from natural gas-fired stationary CTs. If adopted as proposed, the rule would require such natural gas facilities which began construction after December 13, 2024, to install certain pollution control equipment to limit emissions of NOx. In addition, the EPA proposed to maintain the current limits for SO2 at such natural gas facilities. As discussed above, in June 2025, the EPA issued a proposed rule to repeal all greenhouse gas emissions standards for fossil fuel-fired power plants, including the NSPS. The EPA expects to issue a final rule by the end of 2025.

Clean Water Act

All of Ameren Missouri’s coal-fired and nuclear energy centers are subject to Clean Water Act requirements to identify measures for reducing the number of aquatic organisms impinged on a power plant’s cooling water intake screens or entrained through the plant’s cooling water system. Cooling water intake requirements are implemented by state regulators through the permit renewal process of each power plant’s water discharge permit. Permits for Ameren Missouri’s coal-fired and nuclear energy centers have been issued or are in the process of renewal.

CCR Management

The EPA’s 2015 CCR Rule establishes requirements for the management and disposal of CCR from coal-fired power plants and has resulted in the closure of surface impoundments at Ameren Missouri’s energy centers, with closures of surface impoundments in process at its Sioux Energy Center and retired Meramec Energy Center. Ameren Missouri plans to substantially complete the closures of remaining surface impoundments by the end of 2026. Ameren Missouri’s CCR management compliance plan includes installation of groundwater monitoring equipment and groundwater treatment facilities. In April 2024, the EPA revised the CCR Rule to impose groundwater monitoring, and corrective action, closure, and post-closure requirements on certain active and inactive CCR surface impoundments and disposal units not previously included in the 2015 CCR Rule. Ameren and Ameren Missouri have AROs of $40 million associated with CCR storage facilities recorded on their respective balance sheets as of September 30, 2025. This amount includes an immaterial incremental ARO related to the 2024 CCR Rule, which may be revised as additional site studies are performed. The EPA could reconsider aspects of the 2015 and 2024 CCR rules. Ameren and Ameren Missouri are monitoring the ongoing legal challenges and regulatory developments but, at this time, cannot predict the final impacts of the 2024 CCR Rule on their results of operations, financial position, and liquidity.

Remediation

The Ameren Companies are involved in a number of remediation actions to clean up sites impacted by the use or disposal of materials containing hazardous substances. Federal and state laws can require responsible parties to fund remediation regardless of their degree of fault, the legality of original disposal, or the ownership of a disposal site.

As of September 30, 2025, Ameren Illinois has remediated the majority of the 44 former MGP sites in Illinois with an estimated remaining obligation primarily related to three of these former MGP sites at $45 million to $90 million. Ameren and Ameren Illinois recorded a liability of $45 million to represent the estimated minimum obligation for these sites, as no other amount within the range was a better estimate. Ameren and Ameren Illinois cannot estimate the completion dates of the estimated remaining obligation due to site accessibility, among other things.

The scope of the remediation activities at these former MGP sites may increase as remediation efforts continue. Considerable uncertainty remains in these estimates because many site-specific factors can influence the actual costs, including unanticipated underground structures, the degree to which groundwater is impacted, regulatory changes, local ordinances, and site accessibility. The actual costs and timing of completion may vary substantially from these estimates.

The ICC allows Ameren Illinois to recover MGP remediation and related litigation costs from its electric and natural gas utility customers through environmental cost riders that are subject to annual prudence reviews by the ICC.

Our operations or those of our predecessor companies involve the use of, disposal of, and, in appropriate circumstances, the cleanup of substances regulated under environmental laws. Such historical practices may result in future environmental commitments, including additional or more stringent cleanup standards. We are unable to determine whether such historical practices will affect our results of operations, financial position, or liquidity.

NOTE 10 – CALLAWAY ENERGY CENTER

See Note 9 – Callaway Energy Center under Part II, Item 8, of the Form 10-K for information regarding spent nuclear fuel recovery, recovery of decommissioning costs, and the nuclear decommissioning trust fund. The fair value of the trust fund for Ameren Missouri’s Callaway Energy Center is reported as “Nuclear decommissioning trust fund” in Ameren’s and Ameren Missouri’s balance sheets. This amount is legally restricted and may be used only to fund the costs of nuclear decommissioning. Changes in the fair value of the trust fund are recorded as an increase or decrease to the nuclear decommissioning trust fund, with an offsetting adjustment to the related regulatory liability. Ameren and Ameren Missouri have recorded an ARO for the Callaway Energy Center decommissioning costs at fair value, which represents the present value of estimated future cash outflows. Annual decommissioning costs of $7 million have historically been included in the costs used to establish electric rates for Ameren Missouri’s customers. Every three years, the MoPSC requires Ameren Missouri to file an updated cost study and funding analysis for decommissioning its Callaway Energy Center. An updated cost study and funding analysis was filed with the MoPSC in December 2023 and is reflected within the ARO. In May 2025, the MoPSC issued an order that approved a non-unanimous stipulation and agreement between Ameren Missouri and the MoPSC staff that reduced annual customer contributions for funding the Callaway Energy Center decommissioning costs from $7 million to zero, as the trust fund level exceeded the estimated present value of future decommissioning costs at the time of the agreement. This MoPSC order removed Ameren Missouri’s funding obligation effective in June 2025. See Note 13 – Supplemental Information for more information on Ameren Missouri’s AROs.

Insurance

The following table presents insurance coverage at Ameren Missouri’s Callaway Energy Center at September 30, 2025:

Type and Source of Coverage			Most Recent Renewal Date			Maximum Coverages						Maximum Assessments for Single Incidents
Public liability and nuclear worker liability:
American Nuclear Insurers			January 1, 2025			$	500					$	—
Pool participation			(a)			15,763			(a)			166			(b)
						$	16,263		(c)			$	166
Property damage:
NEIL and EMANI			April 1, 2025			$	3,200		(d)			$	22		(e)
Accidental outage:
NEIL			April 1, 2025			$	490		(f)			$	9		(e)

(a)Provided through mandatory participation in an industrywide retrospective premium assessment program. The maximum coverage available is dependent on the number of United States commercial reactors participating in the program.

(b)Retrospective premium under the Price-Anderson Act. This is subject to retrospective assessment with respect to a covered loss in excess of $500 million in the event of an incident at any licensed United States commercial reactor, payable at $25 million per year.

(c)Limit of liability for each incident under the Price-Anderson liability provisions of the Atomic Energy Act of 1954, as amended. This limit is subject to change to account for the effects of inflation and changes in the number of licensed power reactors.

(d)NEIL provides $2.7 billion in property damage, stabilization, decontamination, and premature decommissioning insurance for radiation events and $0.7 billion in property damage insurance for nonradiation events. EMANI provides $490 million in property damage insurance for both radiation and nonradiation events.

(e)All NEIL-insured plants could be subject to retrospective assessments should losses exceed the accumulated funds from NEIL.

(f)Accidental outage insurance provides for lost sales in the event of a prolonged accidental outage. Weekly indemnity up to $4.5 million for 52 weeks, which commences after the first 12 weeks of an outage, plus up to $3.6 million per week for a minimum of 71 weeks thereafter for a total not exceeding the policy limit of $490 million. Nonradiation events are limited to $291 million.

The Price-Anderson Act is a federal law that limits the liability for claims from an incident involving any licensed United States commercial nuclear energy center. The limit is based on the number of licensed reactors. The limit of liability and the maximum potential annual payments are adjusted at least every five years for inflation to reflect changes in the Consumer Price Index. The most recent five-year inflationary adjustment became effective in October 2023. Owners of a nuclear reactor cover this exposure through a combination of private insurance and mandatory participation in a financial protection pool, as established by the Price-Anderson Act.

Losses resulting from terrorist attacks on nuclear facilities insured by NEIL are subject to industrywide aggregates, such that terrorist acts against one or more commercial nuclear power plants within a stated time period would be treated as a single event, and the owners of the nuclear power plants would share the limit of liability. NEIL policies have an aggregate limit of $3.2 billion within a 12-month period for radiation events, or $1.8 billion for events not involving radiation contamination, resulting from terrorist attacks. The EMANI policies are not subject to industrywide aggregates in the event of terrorist attacks on nuclear facilities.

If losses from a nuclear incident at the Callaway Energy Center exceed insurance limits, are not covered by insurance, or if coverage is unavailable, Ameren Missouri is at risk for any uninsured losses. If a serious nuclear incident were to occur, it could have a material adverse effect on Ameren’s and Ameren Missouri’s results of operations, financial position, or liquidity.

NOTE 11 – RETIREMENT BENEFITS

The following table presents the components of the net periodic benefit cost (income) incurred for Ameren’s 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 Ameren’s 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 Ameren’s consolidated statement of income. See Note 5 – Other Income, Net for additional information.

(d)Does not include the impact of the tracker for the difference between the level of pension and postretirement benefit costs (income) incurred by Ameren Missouri under GAAP and the level of such costs included in customer rates.

Ameren Missouri and Ameren Illinois are responsible for their respective share of Ameren’s pension and other postretirement costs. The following table presents the respective share of net periodic pension and other postretirement benefit costs (income) incurred 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
Ameren Missouri(a)			$	(4)					$	(11)					$	(11)					$	(33)								$	(7)					$	(6)					$	(21)					$	(20)
Ameren Illinois			(1)						(8)						(3)						(25)									(13)						(13)						(39)						(39)
Other			(1)						(2)						(2)						(5)									—						—						—						—
Ameren(a)			$	(6)					$	(21)					$	(16)					$	(63)								$	(20)					$	(19)					$	(60)					$	(59)

(a)Does not include the impact of the tracker for the difference between the level of pension and postretirement benefit costs (income) incurred by Ameren Missouri under GAAP and the level of such costs included in customer rates.

NOTE 12 – 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 OBBBA’s 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 OBBBA provisions is subject to additional guidance, regulations, interpretations, amendments, or technical corrections that may be issued by the IRS or United States Department of Treasury.

The following table presents a reconciliation of the federal statutory corporate income tax rate to the effective income tax rate for the three and nine months ended September 30, 2025 and 2024:

			Ameren												Ameren Missouri												Ameren Illinois
			2025						2024						2025						2024						2025						2024
Three Months
Federal statutory corporate income tax rate			21		%				21		%				21		%				21		%				21		%				21		%
Increases (decreases) from:
Amortization of excess deferred taxes(a)			(7)						(9)						(9)						(15)						(4)						(4)
Revaluation of excess deferred income taxes(b)			(7)						—						—						—						(14)						—
Amortization of deferred investment tax credit			(1)						—						(1)						—						—						—
Renewable and other tax credits(c)			(3)						(4)						(7)						(10)						—						—
State tax			5						4						3						3						7						7
Depreciation differences			(1)						—						(1)						(1)						(1)						—
Other permanent items			—						(1)						—						—						1						—
Effective income tax rate			7		%				11		%				6		%				(2)		%				10		%				24		%
Nine Months
Federal statutory corporate income tax rate			21		%				21		%				21		%				21		%				21		%				21		%
Increases (decreases) from:
Amortization of excess deferred taxes(a)			(7)						(8)						(9)						(14)						(4)						(4)
Revaluation of excess deferred income taxes(b)			(3)						—						—						—						(4)						—
Amortization of deferred investment tax credit			(1)						—						(1)						—						—						—
Renewable and other tax credits(c)			(3)						(5)						(7)						(10)						—						—
State tax			5						5						3						3						7						7
Depreciation differences			(1)						—						(1)						(1)						—						—
Effective income tax rate			11		%				13		%				6		%				(1)		%				20		%				24		%

(a)Reflects the amortization of amounts resulting from the revaluation of deferred income taxes subject to regulatory ratemaking, which are being refunded to customers. Deferred income taxes are revalued when federal or state income tax rates change, and the offset to the revaluation of deferred income taxes subject to regulatory ratemaking is recorded to a regulatory asset or liability.

(b)In 2024, the IRS issued a series of private letter rulings to another taxpayer, which provided guidance on applying IRS normalization rules to the calculation of tax benefits applicable to the ratemaking treatment related to net operating loss carryforwards. The rulings concluded that, for ratemaking purposes, net operating loss carryforwards should be reflected on a separate company basis and should not be reduced by payments received for the utilization of losses by other affiliates under a tax allocation agreement. In 2025, the FERC issued an order reflecting implementation of the rules for the other taxpayer who had a similar fact pattern as Ameren Illinois and ATXI. Accordingly, in the third quarter of 2025, Ameren and Ameren Illinois decreased income tax expense by $48 million and $23 million, respectively, to reflect the revaluation of excess deferred income tax regulatory liabilities resulting from TCJA for FERC-regulated jurisdictions pursuant to IRS guidance and recent FERC order.

(c)The benefit of the renewable credits associated with Missouri renewable energy standard compliance is refunded to customers through the RESRAM. The benefit of the renewable credits associated with the production and investment tax credit tracker will be refunded to customers based on MoPSC approval in a regulatory rate review.

NOTE 13 – SUPPLEMENTAL INFORMATION

Cash, Cash Equivalents, and Restricted Cash

The following table provides a reconciliation of cash, cash equivalents, and restricted cash reported within the balance sheets and the statements of cash flows at September 30, 2025, and December 31, 2024:

			September 30, 2025																					December 31, 2024
Ameren						Ameren Missouri						Ameren Illinois									Ameren						Ameren Missouri						Ameren Illinois
“Cash and cash equivalents”			$	9					$	—					$	—								$	7					$	—					$	—
Restricted cash included in “Other current assets” (a)			95						86						6									15						7						6
Restricted cash included in “Other assets”			324						—						324									296						—						296
Restricted cash included in “Nuclear decommissioning trust fund”			7						7						—									10						10						—
Total cash, cash equivalents, and restricted cash			$	435					$	93					$	330								$	328					$	17					$	302

(a)Included in “Restricted cash” on Ameren Missouri’s balance sheet.

Restricted cash included in “Other current assets” represents funds held by an irrevocable Voluntary Employee Beneficiary Association (VEBA) trust, which provides health care benefits for active employees on Ameren’s, Ameren Missouri’s, and Ameren Illinois’ balance sheets, funds held in an escrow account for programs established as a result of a 2024 court order resolving outstanding claims in the NSR and Clean Air Act litigation on Ameren’s and Ameren Missouri’s balance sheets, and AMF’s restricted cash for payments for securitized utility tariff bonds on Ameren’s and Ameren Missouri’s balance sheets. Restricted cash included in “Other assets” on Ameren’s and Ameren Illinois’ balance sheets primarily represents amounts collected under a cost recovery rider restricted for use in the procurement of renewable energy credits and amounts in a trust fund restricted for the use of funding certain asbestos-related claims.

Accounts Receivable

“Accounts receivable – trade” on Ameren’s and Ameren Illinois’ balance sheets include certain receivables purchased at a discount from alternative retail electric suppliers that elect to participate in the utility consolidated billing program. At September 30, 2025, and December 31, 2024, Ameren’s and Ameren Illinois’ balance sheets included payables for purchased receivables of $55 million and $43 million, respectively. On Ameren’s balance sheet, these amounts were included in “Other current liabilities”.

The following table provides a reconciliation of the beginning and ending amount of the allowance for doubtful accounts for the three and nine months ended September 30, 2025 and 2024:

			Three Months															Nine Months
			2025						2024									2025						2024
Ameren:
Beginning of period			$	39					$	37								$	30					$	30
Bad debt expense			18						12									37						28
Charged to other accounts(a)			2						2									5						6
Net write-offs			(21)						(20)									(34)						(33)
End of period			$	38					$	31								$	38					$	31
Ameren Missouri:
Beginning of period			$	12					$	12								$	12					$	12
Bad debt expense			7						3									11						8
Net write-offs			(4)						(3)									(8)						(8)
End of period			$	15					$	12								$	15					$	12
Ameren Illinois:****(b)
Beginning of period			$	27					$	25								$	18					$	18
Bad debt expense			11						9									26						20
Charged to other accounts(a)			2						2									5						6
Net write-offs			(17)						(17)									(26)						(25)
End of period			$	23					$	19								$	23					$	19

(a)Amounts associated with the allowance for doubtful accounts related to receivables purchased by Ameren Illinois from alternative retail electric suppliers, as required by the Illinois Public Utilities Act.

(b)Ameren Illinois has rate-adjustment mechanisms that allow it to recover the difference between its actual net bad debt write-offs under GAAP, including those associated with receivables purchased from alternative retail electric suppliers, and the amount of net bad debt write-offs included in its base rates. The table above does not include the impact related to the riders.

Supplemental Cash Flow Information

The following table provides noncash financing and investing activity excluded from the statements of cash flows for the nine months ended September 30, 2025 and 2024:

			September 30, 2025												September 30, 2024
Ameren			Ameren Missouri						Ameren Illinois			Ameren			Ameren Missouri			Ameren Illinois
Investing:
Accrued capital expenditures, including nuclear fuel expenditures			$	412		$	277					$	147					$	404		$	257		$	127
Net realized and unrealized gain – nuclear decommissioning trust fund			136			136						—						163			163			—
Financing:
Issuance of common stock for stock-based compensation			$	25		$	—					$	—					$	16		$	—		$	—
Issuance of common stock under the DRPlus			7			—						—						7			—			—

Asset Retirement Obligations

The following table provides a reconciliation of the beginning and ending carrying amount of AROs for the nine months ended September 30, 2025:

			Ameren Missouri						Ameren Illinois												Ameren
Balance at December 31, 2024			$	823		(a)			$	4								(b)			$	827		(a)
Liabilities settled			(7)						—												(7)
Accretion			27			(c)			—												27			(c)
Change in estimates			1						1												2
Balance at September 30, 2025			$	844		(a)			$	5								(b)			$	849		(a)

(a)Balance included $5 million in “Other current liabilities” on the balance sheet as of both September 30, 2025, and December 31, 2024.

(b)Included in “Other deferred credits and liabilities” on the balance sheet.

(c)Accretion expense attributable to Ameren Missouri was recorded as a decrease to regulatory liabilities.

Stock-based Compensation

In the first quarter of 2025, Ameren granted 275,869 performance share units with a grant date fair value of $33 million and 118,213 restricted share units with a grant date fair value of $11 million. Awards vest approximately 3 years after the grant date based on continued employment or on a pro-rata basis upon death or eligible retirement. The performance share units vest based on the achievement of certain specified market performance measures (236,448 performance share units) or clean energy transition targets (39,421 performance share units). The exact number of shares issued pursuant to a performance share unit varies from 0% to 200% of the target award, depending on actual company performance relative to the performance goals.

For the nine months ended September 30, 2025 and 2024, excess tax benefits (deficiencies) associated with the settlement of stock-based compensation awards decreased income tax expense by $1 million and increased income tax expense by $1 million, respectively.

Deferred Compensation

At September 30, 2025, and December 31, 2024, the present value of benefits to be paid for deferred compensation obligations was $80 million and $79 million, respectively, which was primarily reflected in “Other deferred credits and liabilities” on Ameren’s consolidated balance sheet.

Operating Revenues

As of September 30, 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

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. The following table presents the excise taxes recorded on a gross basis in “Operating Revenues – Electric,” “Operating Revenues – Natural gas” and “Operating Expenses – Taxes other than income taxes” on the statements of income for the three and nine months ended September 30, 2025 and 2024:

			Three Months												Nine Months
			2025						2024						2025						2024
Ameren Missouri			$	69					$	60					$	150					$	136
Ameren Illinois			30						29						104						94
Ameren			$	99					$	89					$	254					$	230

Earnings per Share

The following table reconciles the basic weighted-average number of common shares outstanding to the diluted weighted-average number of common shares outstanding for the three and nine months ended September 30, 2025 and 2024:

			Three Months												Nine Months
			2025						2024						2025						2024
Weighted-average Common Shares Outstanding – Basic			270.4						266.8						270.2						266.6
Assumed settlement of performance share units and restricted stock units			0.8						0.4						0.9						0.3
Dilutive effect of forward sale agreements			1.0						0.1						0.6						—
Weighted-average Common Shares Outstanding – Diluted(a)			272.2						267.3						271.7						266.9

(a)There was an immaterial number of anti-dilutive performance share units excluded from the earnings per diluted share calculations for the three and nine months ended September 30, 2025 and 2024. Outstanding forward sale agreements as of September 30, 2025 and 2024 that were anti-dilutive for the nine months ended September 30, 2025 and the three and nine months ended September 30, 2024 were excluded from the earnings per diluted share calculation as calculated using the treasury stock method. For additional information about the outstanding forward sale agreements, see Note 4 – Long-term Debt and Equity Financings.

NOTE 14 – 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						988
Three Months 2024:
External revenues			$	1,333					$	551					$	121					$	168					$	—					$	—					$	2,173
Intersegment revenues			9						1						—						42						—						(52)						—
Revenue			1,342						552						121						210						—						(52)						2,173
Fuel and purchased power(a)			(334)						(204)						—						—						—						39						(499)
Natural gas purchased for resale(a)			(4)						—						(26)						—						—						—						(30)
Other operations and maintenance expenses(a)			(288)						(163)						(51)						(19)						(12)						13						(520)
Other segment items
Depreciation and amortization			(220)						(92)						(32)						(42)						(2)						—						(388)
Taxes other than income taxes			(109)						(21)						(14)						(2)						(4)						—						(150)
Other income (expense), net			51						23						6						8						16						(3)						101
Interest charges			(62)						(25)						(16)						(31)						(42)						3						(173)
Income taxes (benefit)			6						(14)						2						(34)						(17)						—						(57)
Noncontrolling interests – preferred stock dividends			(1)						—						—						—						—						—						(1)
Net income (loss) attributable to Ameren common shareholders			381						56						(10)						90			(b)			(61)						—						456
Interest income			2						6						1						—						2						(3)						8
Capital expenditures			735						152						83						174						2						(9)						1,137

			Ameren Missouri						Ameren Illinois Electric Distribution						Ameren Illinois Natural Gas						Ameren Transmission						Other						Intersegment Eliminations						Ameren
Nine Months 2025:
External revenues			$	3,978					$	1,838					$	686					$	515					$	—					$	—					$	7,017
Intersegment revenues			24						6						—						143						—						(173)						—
Revenue			4,002						1,844						686						658						—						(173)						7,017
Fuel and purchased power(a)			(1,431)						(765)						—						—						—						132						(2,064)
Natural gas purchased for resale(a)			(45)						—						(188)						—						—						—						(233)
Other operations and maintenance expenses(a)			(748)						(493)						(165)						(56)						(26)						41						(1,447)
Other segment items
Depreciation and amortization			(642)						(276)						(98)						(146)						(6)						—						(1,168)
Taxes other than income taxes			(300)						(63)						(60)						(7)						(9)						—						(439)
Other income (expense), net			135						66						14						14						31						(3)						257
Interest charges			(215)						(80)						(47)						(89)						(142)						3						(570)
Income (taxes) benefit			(43)						(48)						(37)						(48)						31						—						(145)
Noncontrolling interests – preferred stock dividends			(3)						(1)						—						—						—						—						(4)
Net income (loss) attributable to Ameren common shareholders			710						184						105						326			(b)			(121)						—						1,204
Interest income			7						22						—						2						3						(3)						31
Capital expenditures			1,873						483						225						505						6						26						3,118
Nine Months 2024:
External revenues			$	2,980					$	1,566					$	660					$	476					$	—					$	—					$	5,682
Intersegment revenues			25						1						—						110						—						(136)						—
Revenue			3,005						1,567						660						586						—						(136)						5,682
Fuel and purchased power(a)			(689)						(564)						—						—						—						99						(1,154)
Natural gas purchased for resale(a)			(41)						—						(173)						—						—						—						(214)
Other operations and maintenance expenses(a)			(789)						(452)						(168)						(54)						(29)						37						(1,455)
Other segment items
Depreciation and amortization			(623)						(278)						(98)						(121)						(5)						—						(1,125)
Taxes other than income taxes			(287)						(57)						(55)						(6)						(11)						—						(416)
Other income (expense), net			144						72						20						14						54						(11)						293
Interest charges			(187)						(73)						(46)						(89)						(108)						11						(492)
Income (taxes) benefit			4						(41)						(38)						(89)						24						—						(140)
Noncontrolling interests – preferred stock dividends			(3)						(1)						—						—						—						—						(4)
Net income (loss) attributable to Ameren common shareholders			534						173						102						241			(b)			(75)						—						975
Interest income			7						21						1						1						10						(11)						29
Capital expenditures			1,839						468						202						515						6						(1)						3,029

(a)Significant segment expense that is regularly provided to the CODMs. Intersegment expenses are included within the amounts shown.

(b)Ameren Transmission earnings reflect an allocation of financing costs from Ameren (parent)

Ameren Illinois

			Ameren Illinois Electric Distribution						Ameren Illinois Natural Gas						Ameren Illinois Transmission						Intersegment Eliminations						Ameren Illinois
Three Months 2025:
External revenues			$	699					$	117					$	130					$	—					$	946
Intersegment revenues			—						—						46						(46)						—
Revenue			699						117						176						(46)						946
Purchased power(a)			(330)						—						—						46						(284)
Natural gas purchased for resale(a)			—						(19)						—						—						(19)
Other operations and maintenance expenses(a)			(171)						(55)						(15)						—						(241)
Other segment items
Depreciation and amortization			(92)						(33)						(37)						—						(162)
Taxes other than income taxes			(22)						(15)						(1)						—						(38)
Other income, net			20						4						6						—						30
Interest charges			(28)						(16)						(23)						—						(67)
Income taxes			(19)						4						(2)						—						(17)
Net income (loss) available to common shareholder			57						(13)						104						—						148
Interest income			6						—						1						—						7
Capital expenditures			163						78						144						—						385
Three Months 2024:
External revenues			$	552					$	121					$	120					$	—					$	793
Intersegment revenues			—						—						35						(35)						—
Revenue			552						121						155						(35)						793
Purchased power(a)			(204)						—						—						35						(169)
Natural gas purchased for resale(a)			—						(26)						—						—						(26)
Other operations and maintenance expenses(a)			(163)						(51)						(15)						—						(229)
Other segment items
Depreciation and amortization			(92)						(32)						(31)						—						(155)
Taxes other than income taxes			(21)						(14)						(2)						—						(37)
Other income, net			23						6						8						—						37
Interest charges			(25)						(16)						(22)						—						(63)
Income taxes			(14)						2						(25)						—						(37)
Net income (loss) available to common shareholder			56						(10)						68						—						114
Interest income			6						1						—						—						7
Capital expenditures			152						83						139						—						374
Nine Months 2025:
External revenues			$	1,844					$	686					$	359					$	—					$	2,889
Intersegment revenues			—						—						123						(123)						—
Revenue			1,844						686						482						(123)						2,889
Purchased power(a)			(765)						—						—						123						(642)
Natural gas purchased for resale(a)			—						(188)						—												(188)
Other operations and maintenance expenses(a)			(493)						(165)						(44)												(702)
Other segment items
Depreciation and amortization			(276)						(98)						(110)												(484)
Taxes other than income taxes			(63)						(60)						(3)												(126)
Other income, net			66						14						21												101
Interest charges			(80)						(47)						(65)												(192)
Income taxes			(48)						(37)						(49)												(134)
Noncontrolling interests – preferred stock dividends			(1)						—						—												(1)
Net income available to common shareholder			184						105						232						—						521
Interest income			22						—						2						—						24
Capital expenditures			483						225						419						—						1,127

			Ameren Illinois Electric Distribution						Ameren Illinois Natural Gas						Ameren Illinois Transmission						Intersegment Eliminations						Ameren Illinois
Nine Months 2024:
External revenues			$	1,567					$	660					$	332					$	—					$	2,559
Intersegment revenues			—						—						90						(90)						—
Revenue			1,567						660						422						(90)						2,559
Purchased power(a)			(564)						—						—						90						(474)
Natural gas purchased for resale(a)			—						(173)						—												(173)
Other operations and maintenance expenses(a)			(452)						(168)						(43)												(663)
Other segment items
Depreciation and amortization			(278)						(98)						(86)												(462)
Taxes other than income taxes			(57)						(55)						(4)												(116)
Other income, net			72						20						13												105
Interest charges			(73)						(46)						(59)												(178)
Income taxes			(41)						(38)						(65)												(144)
Noncontrolling interests – preferred stock dividends			(1)						—						—												(1)
Net income available to common shareholder			173						102						178						—						453
Interest income			21						1						—						—						22
Capital expenditures			468						202						421						—						1,091

(a)Significant segment expense that is regularly provided to the CODMs. Intersegment expenses are included within the amounts shown.

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 revenues(b)			$	1,342					$	552					$	121					$	210											$	(52)					$	2,173
Nine Months 2025:
Residential			$	1,483					$	1,132					$	—					$	—											$	—					$	2,615
Commercial			1,154						596						—						—												—						1,750
Industrial			269						144						—						—												—						413
Other			987						(28)			(a)			—						658												(172)						1,445
Total electric revenues			$	3,893					$	1,844					$	—					$	658											$	(172)					$	6,223
Residential			$	65					$	—					$	486					$	—											$	—					$	551
Commercial			29						—						126						—												—						155
Industrial			3						—						9						—												—						12
Other			12						—						65						—												(1)						76
Total natural gas revenues			$	109					$	—					$	686					$	—											$	(1)					$	794
Total revenues(b)			$	4,002					$	1,844					$	686					$	658											$	(173)					$	7,017

			Ameren Missouri						Ameren Illinois Electric Distribution						Ameren Illinois Natural Gas						Ameren Transmission												Intersegment Eliminations						Ameren
Nine Months 2024:
Residential			$	1,326					$	947					$	—					$	—											$	—					$	2,273
Commercial			1,048						512						—						—												—						1,560
Industrial			246						130						—						—												—						376
Other			282						(22)			(a)			—						586												(135)						711
Total electric revenues			$	2,902					$	1,567					$	—					$	586											$	(135)					$	4,920
Residential			$	62					$	—					$	466					$	—											$	—					$	528
Commercial			26						—						111						—												—						137
Industrial			3						—						7						—												—						10
Other			12						—						76						—												(1)						87
Total natural gas revenues			$	103					$	—					$	660					$	—											$	(1)					$	762
Total revenues(b)			$	3,005					$	1,567					$	660					$	586											$	(136)					$	5,682

(a)Includes over-recoveries of various riders.

(b)The following table presents increases/(decreases) in revenues from alternative revenue programs and other revenues not from contracts with customers for the three and nine months ended September 30, 2025 and 2024:

			Ameren Missouri						Ameren Illinois Electric Distribution						Ameren Illinois Natural Gas						Ameren Transmission						Intersegment Eliminations						Ameren
Three Months 2025:
Revenues from alternative revenue programs			$	—					$	(187)					$	(10)					$	(12)					$	—					$	(209)
Other revenues not from contracts with customers			2						3						—						—						—						5
Three Months 2024:
Revenues from alternative revenue programs			$	—					$	(144)					$	(9)					$	(2)					$	—					$	(155)
Other revenues not from contracts with customers			2						2						—						—						—						4
Nine Months 2025:
Revenues from alternative revenue programs			$	(4)					$	(174)					$	(6)					$	(21)					$	—					$	(205)
Other revenues not from contracts with customers			5						11						2						—						(4)						14
Nine Months 2024:
Revenues from alternative revenue programs			$	(7)					$	(83)					$	10					$	11					$	—					$	(69)
Other revenues not from contracts with customers			4						5						2						—						—						11

Ameren Illinois

			Ameren Illinois Electric Distribution						Ameren Illinois Natural Gas						Ameren Illinois Transmission						Intersegment Eliminations						Ameren Illinois
Three Months 2025:
Residential			$	469					$	70					$	—					$	—					$	539
Commercial			235						21						—						—						256
Industrial			46						2						—						—						48
Other			(51)			(a)			24						176						(46)						103
Total revenues(b)			$	699					$	117					$	176					$	(46)					$	946
Three Months 2024:
Residential			$	339					$	77					$	—					$	—					$	416
Commercial			184						19						—						—						203
Industrial			38						2						—						—						40
Other			(9)			(a)			23						155						(35)						134
Total revenues(b)			$	552					$	121					$	155					$	(35)					$	793
Nine Months 2025:
Residential			$	1,132					$	486					$	—					$	—					$	1,618
Commercial			596						126						—						—						722
Industrial			144						9						—						—						153
Other			(28)			(a)			65						482						(123)						396
Total revenues(b)			$	1,844					$	686					$	482					$	(123)					$	2,889
Nine Months 2024:
Residential			$	947					$	466					$	—					$	—					$	1,413
Commercial			512						111						—						—						623
Industrial			130						7						—						—						137
Other			(22)			(a)			76						422						(90)						386
Total revenues(b)			$	1,567					$	660					$	422					$	(90)					$	2,559

(a)Includes over-recoveries of various riders.

(b)The following table presents increases/(decreases) in revenues from alternative revenue programs and other revenues not from contracts with customers for the Ameren Illinois segments for the three and nine months ended September 30, 2025 and 2024:

			Ameren Illinois Electric Distribution						Ameren Illinois Natural Gas						Ameren Illinois Transmission						Ameren Illinois
Three Months 2025:
Revenues from alternative revenue programs			$	(187)					$	(10)					$	(12)					$	(209)
Other revenues not from contracts with customers			3						—						—						3
Three Months 2024:
Revenues from alternative revenue programs			$	(144)					$	(9)					$	(1)					$	(154)
Other revenues not from contracts with customers			2						—						—						2
Nine Months 2025:
Revenues from alternative revenue programs			$	(174)					$	(6)					$	(20)					$	(200)
Other revenues not from contracts with customers			11						2						—						13
Nine Months 2024:
Revenues from alternative revenue programs			$	(83)					$	10					$	9					$	(64)
Other revenues not from contracts with customers			5						2						—						7