Income Taxes

3 Months Ended

Mar. 31, 2022

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. The increases in Alliant Energy’s and WPL’s overall effective income tax rates for the three months ended March 31, 2022 compared to the same period in 2021 were primarily due to decreased amortization of excess deferred taxes primarily at WPL.

	Alliant Energy		IPL		WPL
	2022	2021	2022	2021	2022	2021
Overall income tax rate	4%	(19%)	(14%)	(17%)	19%	(29%)

Deferred Tax Assets and Liabilities -

Carryforwards - At March 31, 2022, carryforwards and expiration dates were estimated as follows (in millions):

	Range of Expiration Dates	Alliant Energy	IPL	WPL
Federal net operating losses	2037	$94	$87	$1
State net operating losses	2022-2042	578	13	2
Federal tax credits	2022-2042	589	369	197

Iowa Tax Reform - In March 2022, Iowa tax reform was enacted, which would reduce the current 9.8% Iowa corporate income tax rate beginning in 2023 if certain state income tax revenue triggers are satisfied. Annually, and by each November 1, the Iowa Department of Revenue will establish corporate income tax rates for the next tax year based on net corporate income tax receipts for the prior tax year. Rate reductions are currently expected to occur over a period of several years, with a target corporate income tax rate of 5.5%. Alliant Energy is currently unable to predict with certainty the timing or amount of any rate reductions. The majority of any reduction in income tax expense as a result of the lower Iowa corporate income tax rate is currently expected to reduce rates for IPL’s customers. In addition, after the 2023 corporate income tax rate is known in the fourth quarter of 2022, Alliant Energy currently expects to record a charge related to the remeasurement of accumulated deferred income tax assets at its non-utility businesses.

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. The increases in Alliant Energy’s and WPL’s overall effective income tax rates for the three months ended March 31, 2022 compared to the same period in 2021 were primarily due to decreased amortization of excess deferred taxes primarily at WPL.

	Alliant Energy		IPL		WPL
	2022	2021	2022	2021	2022	2021
Overall income tax rate	4%	(19%)	(14%)	(17%)	19%	(29%)

Deferred Tax Assets and Liabilities -

Carryforwards - At March 31, 2022, carryforwards and expiration dates were estimated as follows (in millions):

	Range of Expiration Dates	Alliant Energy	IPL	WPL
Federal net operating losses	2037	$94	$87	$1
State net operating losses	2022-2042	578	13	2
Federal tax credits	2022-2042	589	369	197

Iowa Tax Reform - In March 2022, Iowa tax reform was enacted, which would reduce the current 9.8% Iowa corporate income tax rate beginning in 2023 if certain state income tax revenue triggers are satisfied. Annually, and by each November 1, the Iowa Department of Revenue will establish corporate income tax rates for the next tax year based on net corporate income tax receipts for the prior tax year. Rate reductions are currently expected to occur over a period of several years, with a target corporate income tax rate of 5.5%. Alliant Energy is currently unable to predict with certainty the timing or amount of any rate reductions. The majority of any reduction in income tax expense as a result of the lower Iowa corporate income tax rate is currently expected to reduce rates for IPL’s customers. In addition, after the 2023 corporate income tax rate is known in the fourth quarter of 2022, Alliant Energy currently expects to record a charge related to the remeasurement of accumulated deferred income tax assets at its non-utility businesses.

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. The increases in Alliant Energy’s and WPL’s overall effective income tax rates for the three months ended March 31, 2022 compared to the same period in 2021 were primarily due to decreased amortization of excess deferred taxes primarily at WPL.

	Alliant Energy		IPL		WPL
	2022	2021	2022	2021	2022	2021
Overall income tax rate	4%	(19%)	(14%)	(17%)	19%	(29%)

Deferred Tax Assets and Liabilities -

Carryforwards - At March 31, 2022, carryforwards and expiration dates were estimated as follows (in millions):

	Range of Expiration Dates	Alliant Energy	IPL	WPL
Federal net operating losses	2037	$94	$87	$1
State net operating losses	2022-2042	578	13	2
Federal tax credits	2022-2042	589	369	197

Iowa Tax Reform - In March 2022, Iowa tax reform was enacted, which would reduce the current 9.8% Iowa corporate income tax rate beginning in 2023 if certain state income tax revenue triggers are satisfied. Annually, and by each November 1, the Iowa Department of Revenue will establish corporate income tax rates for the next tax year based on net corporate income tax receipts for the prior tax year. Rate reductions are currently expected to occur over a period of several years, with a target corporate income tax rate of 5.5%. Alliant Energy is currently unable to predict with certainty the timing or amount of any rate reductions. The majority of any reduction in income tax expense as a result of the lower Iowa corporate income tax rate is currently expected to reduce rates for IPL’s customers. In addition, after the 2023 corporate income tax rate is known in the fourth quarter of 2022, Alliant Energy currently expects to record a charge related to the remeasurement of accumulated deferred income tax assets at its non-utility businesses.