Supplemental Information (Tables)

3 Months Ended

Mar. 31, 2022

Supplemental Information [Abstract]

Schedule of Cash and Cash Equivalents Including 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 March 31, 2022, and December 31, 2021:

	March 31, 2022						December 31, 2021
	Ameren		Ameren Missouri		Ameren Illinois		Ameren		Ameren Missouri		Ameren Illinois
“Cash and cash equivalents”	$	7	$	1	$	—	$	8	$	—	$	—
Restricted cash included in “Other current assets”	10		3		5		16		4		6
Restricted cash included in “Other assets”	132		—		132		127		—		127
Restricted cash included in “Nuclear decommissioning trust fund”	5		5		—		4		4		—
Total cash, cash equivalents, and restricted cash	$	154	$	9	$	137	$	155	$	8	$	133

Schedule of Accounts, Notes, Loans and Financing Receivable

The following table provides a reconciliation of the beginning and ending amount of the allowance for doubtful accounts for the three months ended March 31, 2022 and 2021:

	Three Months
	2022		2021
Ameren:
Beginning of period	$	29	$	50
Bad debt expense	4		4
Net write-offs	(5)		(7)
End of period	$	28	$	47
Ameren Missouri:
Beginning of period	$	13	$	16
Bad debt expense	1		1
Net write-offs	(3)		(2)
End of period	$	11	$	15
Ameren Illinois:(a)
Beginning of period	$	16	$	34
Bad debt expense	3		3
Net write-offs	(2)		(5)
End of period	$	17	$	32

(a)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.

Schedule of Cash Flow, Supplemental Disclosures

The following table provides noncash financing and investing activity excluded from the statements of cash flows for the three months ended March 31, 2022 and 2021:

	March 31, 2022						March 31, 2021
	Ameren		Ameren Missouri		Ameren Illinois		Ameren		Ameren Missouri		Ameren Illinois
Investing
Accrued capital expenditures	$	345	$	194	$	147	$	271	$	141	$	139
Net realized and unrealized gain/(loss) – nuclear decommissioning trust fund	(71)		(71)		—		22		22		—
Financing
Issuance of common stock for stock-based compensation	$	31	$	—	$	—	$	33	$	—	$	—
Issuance of common stock under the DRPlus	8		—		—		—		—		—

Asset Retirement Obligation Disclosure

The following table provides a reconciliation of the beginning and ending carrying amount of AROs for the three months ended March 31, 2022:

	Ameren Missouri			Ameren Illinois			Ameren
Balance at December 31, 2021	$	760	(a)	$	4	(b)	$	764	(a)
Accretion	8		(c)	—			8		(c)
Change in estimates	4		(d)	—			4		(d)
Balance at March 31, 2022	$	772	(a)	$	4	(b)	$	776	(a)

(a)Balance included $7 million in “Other current liabilities” on the balance sheet as of both March 31, 2022, and December 31, 2021.

(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.

(d)Ameren Missouri changed its fair value estimate primarily due to the change in useful life of the Sioux Energy Center, as reflected in depreciation rates approved by the December 2021 electric rate order, which became effective in 2022.

Schedule of excise taxes

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 months ended March 31, 2022 and 2021:

	Three Months
	2022		2021
Ameren Missouri	$	34	$	31
Ameren Illinois	45		39
Ameren	$	79	$	70

Schedule of Earnings Per Share, Basic and Diluted

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 months ended March 31, 2022 and 2021:

	Three Months
	2022	2021
Weighted-average Common Shares Outstanding – Basic	257.9	254.4
Assumed settlement of performance share units and restricted stock units	1.1	1.5
Weighted-average Common Shares Outstanding – Diluted(a)	259.0	255.9

(a)There was an immaterial number of anti-dilutive securities excluded from the earnings per diluted share calculations for the three months ended March 31, 2022. There were no anti-dilutive securities excluded from the earnings per diluted share calculations for the three months ended March 31, 2021.