Income Taxes

6 Months Ended

Jun. 30, 2021

Income Taxes [Line Items]

Income Taxes

INCOME TAXESIncome 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. The decreases in Alliant Energy’s, IPL’s and WPL’s overall effective income tax rates for the three and six months ended June 30, 2021 compared to the same periods in 2020 were primarily due to increased amortization of excess deferred taxes primarily at WPL, which were used to offset increases in WPL’s 2021 increased revenue requirements, and increased production tax credits at IPL.

	Alliant Energy				IPL				WPL
	Three Months		Six Months		Three Months		Six Months		Three Months		Six Months
	2021	2020	2021	2020	2021	2020	2021	2020	2021	2020	2021	2020
Overall income tax rate	(13%)	(6%)	(16%)	(10%)	(13%)	(7%)	(15%)	(14%)	(23%)	(9%)	(27%)	(9%)

Deferred Tax Assets and Liabilities -

Carryforwards - At June 30, 2021, carryforwards and expiration dates were estimated as follows (in millions):

	Range of Expiration Dates	Alliant Energy	IPL	WPL
Federal net operating losses	2037	$322	$297	$3
State net operating losses	2021-2041	652	29	2
Federal tax credits	2022-2041	506	302	182

IPL [Member]

Income Taxes [Line Items]

Income Taxes

INCOME TAXESIncome 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. The decreases in Alliant Energy’s, IPL’s and WPL’s overall effective income tax rates for the three and six months ended June 30, 2021 compared to the same periods in 2020 were primarily due to increased amortization of excess deferred taxes primarily at WPL, which were used to offset increases in WPL’s 2021 increased revenue requirements, and increased production tax credits at IPL.

	Alliant Energy				IPL				WPL
	Three Months		Six Months		Three Months		Six Months		Three Months		Six Months
	2021	2020	2021	2020	2021	2020	2021	2020	2021	2020	2021	2020
Overall income tax rate	(13%)	(6%)	(16%)	(10%)	(13%)	(7%)	(15%)	(14%)	(23%)	(9%)	(27%)	(9%)

Deferred Tax Assets and Liabilities -

Carryforwards - At June 30, 2021, carryforwards and expiration dates were estimated as follows (in millions):

	Range of Expiration Dates	Alliant Energy	IPL	WPL
Federal net operating losses	2037	$322	$297	$3
State net operating losses	2021-2041	652	29	2
Federal tax credits	2022-2041	506	302	182

WPL [Member]

Income Taxes [Line Items]

Income Taxes

INCOME TAXESIncome 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. The decreases in Alliant Energy’s, IPL’s and WPL’s overall effective income tax rates for the three and six months ended June 30, 2021 compared to the same periods in 2020 were primarily due to increased amortization of excess deferred taxes primarily at WPL, which were used to offset increases in WPL’s 2021 increased revenue requirements, and increased production tax credits at IPL.

	Alliant Energy				IPL				WPL
	Three Months		Six Months		Three Months		Six Months		Three Months		Six Months
	2021	2020	2021	2020	2021	2020	2021	2020	2021	2020	2021	2020
Overall income tax rate	(13%)	(6%)	(16%)	(10%)	(13%)	(7%)	(15%)	(14%)	(23%)	(9%)	(27%)	(9%)

Deferred Tax Assets and Liabilities -

Carryforwards - At June 30, 2021, carryforwards and expiration dates were estimated as follows (in millions):

	Range of Expiration Dates	Alliant Energy	IPL	WPL
Federal net operating losses	2037	$322	$297	$3
State net operating losses	2021-2041	652	29	2
Federal tax credits	2022-2041	506	302	182