Schedule II - Valuation And Qualifying Accounts

12 Months Ended

Dec. 31, 2020

SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]

Valuation And Qualifying Accounts

SCHEDULE II – VALUATION AND QUALIFYING ACCOUNTS FOR THE YEARS ENDED DECEMBER 31, 2020, 2019, AND 2018
(In millions)
Column A	Column B		Column C				Column D		Column E
Description	Balance at Beginning of Period		(1) Charged to Costs and Expenses		(2) Charged to Other Accounts(a)		Deductions(b)		Balance at End of Period
Ameren:
Deducted from assets – allowance for doubtful accounts:
2020	$	17	$	42	$	6	$	15	$	50
2019	18		26		4		31		17
2018	19		27		4		32		18
Deferred tax valuation allowance:
2020	$	3	$	—	$	—	$	—	$	3
2019	5		(2)		—		—		3
2018	11		(6)		—		—		5
Ameren Missouri:
Deducted from assets – allowance for doubtful accounts:
2020	$	7	$	15	$	—	$	6	$	16
2019	7		9		—		9		7
2018	7		9		—		9		7
Ameren Illinois:
Deducted from assets – allowance for doubtful accounts:
2020	$	10	$	27	$	6	$	9	$	34
2019	11		17		4		22		10
2018	12		18		4		23		11

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

(b)Uncollectible accounts charged off, less recoveries.