Income Taxes

3 Months Ended

Mar. 31, 2023

Income Taxes [Line Items]

Income Taxes

INCOME TAXES

Income Tax Rates - Overall effective income tax rates, which were computed by dividing income tax expense (benefit) by income before income taxes, were as follows. The effective income tax rates were different than the federal statutory rate primarily due to state income taxes, production tax credits, amortization of excess deferred taxes and the effect of rate-making on property-related differences.

	Alliant Energy		IPL		WPL
	2023	2022	2023	2022	2023	2022
Overall income tax rate	(1%)	4%	(18%)	(14%)	12%	19%

Deferred Tax Assets and Liabilities -

Carryforwards - At March 31, 2023, the carryforwards and expiration dates were estimated as follows (in millions):

	Range of Expiration Dates	Alliant Energy	IPL	WPL
State net operating losses	2025-2043	$535	$12	$1
Federal tax credits	2027-2043	698	468	218

IPL [Member]

Income Taxes [Line Items]

Income Taxes

INCOME TAXES

Income Tax Rates - Overall effective income tax rates, which were computed by dividing income tax expense (benefit) by income before income taxes, were as follows. The effective income tax rates were different than the federal statutory rate primarily due to state income taxes, production tax credits, amortization of excess deferred taxes and the effect of rate-making on property-related differences.

	Alliant Energy		IPL		WPL
	2023	2022	2023	2022	2023	2022
Overall income tax rate	(1%)	4%	(18%)	(14%)	12%	19%

Deferred Tax Assets and Liabilities -

Carryforwards - At March 31, 2023, the carryforwards and expiration dates were estimated as follows (in millions):

	Range of Expiration Dates	Alliant Energy	IPL	WPL
State net operating losses	2025-2043	$535	$12	$1
Federal tax credits	2027-2043	698	468	218

WPL [Member]

Income Taxes [Line Items]

Income Taxes

INCOME TAXES

Income Tax Rates - Overall effective income tax rates, which were computed by dividing income tax expense (benefit) by income before income taxes, were as follows. The effective income tax rates were different than the federal statutory rate primarily due to state income taxes, production tax credits, amortization of excess deferred taxes and the effect of rate-making on property-related differences.

	Alliant Energy		IPL		WPL
	2023	2022	2023	2022	2023	2022
Overall income tax rate	(1%)	4%	(18%)	(14%)	12%	19%

Deferred Tax Assets and Liabilities -

Carryforwards - At March 31, 2023, the carryforwards and expiration dates were estimated as follows (in millions):

	Range of Expiration Dates	Alliant Energy	IPL	WPL
State net operating losses	2025-2043	$535	$12	$1
Federal tax credits	2027-2043	698	468	218