ALLIANT ENERGY CORP

NOTE 9. INCOME TAXES

Income Tax Rates -Overall effective income tax rates for the three and nine months ended September 30, 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, investment tax credits, amortization of excess deferred taxes and the effect of rate-making on property-related differences. Also impacting Alliant Energy’s and IPL’s effective income tax rates for the nine months ended September 30, 2024 were the pre-tax non-cash charge of $60 million for IPL’s Lansing Generation Station discussed in Note 2 and the pre-tax non-cash charge of $20 million for the portion of recorded AROs allocated to IPL’s steam business discussed in Note 11.

Deferred Tax Assets and Liabilities -

Carryforwards -At September 30, 2024, the carryforwards and expiration dates were estimated as follows (in millions):

Iowa Tax Reform - Pursuant to Iowa tax reform enacted in 2022, and based on the remeasurement of Alliant Energy parent company’s deferred tax assets in the third quarter of 2023 for the Iowa corporate income tax rate of 7.1% effective January 1, 2024, a charge of $8 million was recorded to income tax expense in Alliant Energy’s income statement in the third quarter of 2023.