The following table provides a reconciliation of cash, cash equivalents, and restricted cash reported within the balance sheets and the statements of cash flows as of December 31, 2021 and 2020:


	December 31, 2021						December 31, 2020
	Ameren		Ameren Missouri		Ameren Illinois		Ameren		Ameren Missouri		Ameren Illinois
Cash and cash equivalents	$	8	$	—	$	—	$	139	$	136	$	—
Restricted cash included in “Other current assets”	16		4		6		17		5		6
Restricted cash included in “Other assets”	127		—		127		141		—		141
Restricted cash included in “Nuclear decommissioning trust fund”	4		4		—		4		4		—
Total cash, cash equivalents, and restricted cash	$	155	$	8	$	133	$	301	$	145	$	147

Restricted cash included in “Other current assets” primarily represents funds held by an irrevocable Voluntary Employee Beneficiary Association (VEBA) trust, which provides health care benefits for active employees. 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 – 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 December 31, 2021 and 2020, “Other current liabilities” on Ameren’s and Ameren Illinois’ balance sheets included payables for purchased receivables of $27 million and $28 million, respectively.


	December 31, 2021							December 31, 2020
	Ameren Missouri		Ameren Illinois(a)			Ameren		Ameren Missouri		Ameren Illinois(a)		Ameren
Beginning of period	$	16	$	34		$	50	$	7	$	10	$	17
Bad debt expense	5		4		(b)	9		15		33		48

Net write-offs	(8)		(22)			(30)		(6)		(9)		(15)
End of period	$	13	$	16		$	29	$	16	$	34	$	50

(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.

(b)In 2021, Ameren Illinois’ bad debt expense was reduced as a result of incremental state funding received for customer bill assistance. The incremental state funding granted relief to low-income customers at risk of service disconnection resulting from the impacts of the COVID-19 pandemic.

Net write-offs increased for the year ended December 31, 2021 due to the resumption of disconnection activities for nonpayment. See Note 2 – Rate and Regulatory Matters for additional information.


	December 31, 2021						December 31, 2020
	Ameren Missouri		Ameren Illinois		Ameren		Ameren Missouri		Ameren Illinois		Ameren
Fuel(a)	$	118	$	—	$	118	$	115	$	—	$	115
Natural gas stored underground	9		90		99		5		52		57
Materials, supplies, and other	292		83		375		266		83		349
Total inventories	$	419	$	173	$	592	$	386	$	135	$	521

In January 2021, Ameren Missouri acquired a 300-MW wind generation project located in northwestern Missouri. As of June 30, 2021, Ameren Missouri had placed the project in service as the Atchison Renewable Energy Center. The purchase price of the energy center was approximately $500 million, including an immaterial amount of transaction costs. In December 2020, Ameren Missouri acquired a 400-MW wind generation project located in northeastern Missouri for approximately $615 million, and placed the assets in service as the High Prairie Renewable Energy Center. The purchase price included $564 million of cash, a deferred purchase price obligation withheld as credit support in relation to certain potential claims, contingent consideration, and transaction costs. Both renewable energy centers support Ameren Missouri’s compliance with the Missouri renewable energy standard.


	December 31, 2021									December 31, 2020
	Ameren Missouri			Ameren Illinois			Ameren				Ameren Missouri			Ameren Illinois			Ameren
Beginning balance at January 1	$	751		$	5	(a)	$	756	(b)		$	687		$	4		$	691
Liabilities incurred	18		(c)	—			18		(c)		36		(c)	—			36		(c)
Liabilities settled	(36)			(1)			(37)				(58)			—			(58)
Accretion(d)	31			—			31				29			1			30
Change in estimates	(4)		(e)	—			(4)		(e)		57		(f)	—			57		(f)
Ending balance at December 31	$	760	(g)	$	4	(a)	$	764	(b)(g)		$	751		$	5	(a)	$	756	(b)

(d)Accretion expense attributable to Ameren Missouri and Ameren Illinois was recorded as a decrease to regulatory liabilities and an increase to regulatory assets, respectively.

(e)Ameren Missouri changed its fair value estimate primarily due to a decrease in the cost estimate for closure of certain CCR storage facilities, partially offset by an increase due to the planned accelerated retirement of the Rush Island Energy Center.

(f)Ameren Missouri changed its fair value estimate primarily due to an update to the decommissioning of the Callaway Energy Center to reflect the cost study and funding analysis filed with the MoPSC in November 2020 and an increase in the cost estimate for closure of certain CCR storage facilities.

As of December 31, 2021, and 2020, the present value of benefits to be paid for deferred compensation obligations was $91 million and $90 million, respectively, which was primarily reflected in “Other deferred credits and liabilities” on Ameren’s consolidated balance sheet.

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 years ended December 31, 2021, 2020, and 2019:

The following table presents the average rate that was applied to eligible construction work in progress and the amounts of allowance for funds used during construction capitalized in 2021, 2020, and 2019:


	2021			2020			2019
Average rate:
Ameren Missouri	6		%	5		%	6		%
Ameren Illinois	5		%	5		%	5		%
Ameren:
Allowance for equity funds used during construction	$	43		$	32		$	28
Allowance for borrowed funds used during construction	17			16			20
Total Ameren	$	60		$	48		$	48
Ameren Missouri:
Allowance for equity funds used during construction	$	26		$	19		$	19
Allowance for borrowed funds used during construction	10			10			12
Total Ameren Missouri	$	36		$	29		$	31
Ameren Illinois:
Allowance for equity funds used during construction	$	17		$	13		$	9
Allowance for borrowed funds used during construction	7			6			8
Total Ameren Illinois	$	24		$	19		$	17

Earnings per basic and diluted share are computed by dividing “Net Income Attributable to Ameren Common Shareholders” by the weighted-average number of basic and diluted common shares outstanding, respectively, during the applicable period. The weighted-average shares outstanding for earnings per diluted share includes the incremental effects resulting from performance share units, restricted stock units, and forward sale agreements relating to common stock when the impact would be dilutive, as calculated using the treasury stock method. For information regarding performance share units and restricted stock units, see Note 11 – Stock-based Compensation. For information regarding forward sale agreements, see Note 5 – Long-term Debt and Equity Financings.

The following table reconciles the weighted-average number of common shares outstanding to the diluted weighted-average number of common shares outstanding for the years ended December 31, 2021, 2020, and 2019:


	2021	2020	2019


Weighted-average Common Shares Outstanding – Basic	256.3	247.0	245.6
Assumed settlement of performance share units and restricted stock units	1.3	1.2	1.4
Dilutive effect of forward sale agreements	—	0.5	0.1
Weighted-average Common Shares Outstanding – Diluted(a)	257.6	248.7	247.1

(a)There was an immaterial number of anti-dilutive securities excluded from the earnings per diluted share calculations for the year ended December 31, 2021. There were no potentially dilutive securities excluded from the earnings per diluted share calculations for the years ended December 31, 2020 and 2019.


	December 31, 2021						December 31, 2020							December 31, 2019
	Ameren		Ameren Missouri		Ameren Illinois			Ameren		Ameren Missouri		Ameren Illinois			Ameren		Ameren Missouri		Ameren Illinois
Investing
Accrued capital expenditures, including wind generation expenditures	$	508	$	285	$	215		$	446	$	229	$	218		$	333	$	140	$	163
Accrued nuclear fuel expenditures	16		16		—			—		—		—			19		19		—

Net realized and unrealized gain – nuclear decommissioning trust fund	163		163		—			116		116		—			143		143		—
Exchange of bond investments for the extinguishment of senior unsecured notes(a)	—		—		—			—		—		—			17		—		17
Financing
Issuance of common stock for stock-based compensation	$	33	$	—	$	—		$	38	$	—	$	—		$	54	$	—	$	—
Exchange of bond investments for the extinguishment of senior unsecured notes(a)	—		—		—			—		—		—			(17)		—		(17)

(a)In 2006, Ameren Illinois purchased all $17 million of the 1993 Series B-1 bonds due 2028 issued by the Illinois Finance Authority on behalf of Ameren Illinois pursuant to a mandatory tender. Ameren Illinois’ 1993 Series B-1 senior unsecured notes due 2028 were not extinguished and remained as “Long-term debt, net” on Ameren’s and Ameren Illinois’ balance sheets. In September 2019, Ameren Illinois exchanged its bond investments for the extinguishment of its senior unsecured notes.