ALLIANT ENERGY CORP

Construction and Acquisition Expenditures - Construction and acquisition expenditures and financing plans are reviewed, approved and updated as part of the strategic planning process. Changes may result from a number of reasons, including changes in expected load growth, regulatory requirements, changing legislation, not obtaining favorable and acceptable regulatory approval on certain projects, changing costs of projects due to market conditions and the impact of tariffs, improvements in technology, and improvements to ensure resiliency and reliability of the electric and gas distribution systems. Alliant Energy, IPL and WPL have not yet entered into contractual commitments relating to the majority of their anticipated future construction and acquisition expenditures. As a result, they have some discretion with regard to the level and timing of these expenditures. Construction and acquisition expenditures for 2025 through 2028 are currently anticipated as follows (in millions), which are focused on adding generation to meet growing customer demand for electricity, including expected future data center growth from currently executed electric service agreements, and strengthening the resiliency and reliability of the electric grid, and include renewable generation and energy storage projects, dispatchable gas generation projects, and converting certain coal-fired EGUs to natural gas. Alliant Energy, IPL and WPL are currently evaluating the impacts of tariffs, recently enacted legislation and additional potential large load growth customers on their resource plans, and will update their anticipated construction and acquisition expenditures as needed in the future. Cost estimates represent Alliant Energy’s, IPL’s and WPL’s portion of construction expenditures and exclude allowance for funds used during construction and capitalized interest, if applicable.

Financing Activities - The following items contributed to increased (decreased) financing activity cash flows for the six months ended June 30, 2025 compared to the same period in 2024 (in millions):

Common Stock Issuances - Refer to Note 5 for discussion of common stock issuances by Alliant Energy in 2025 and Alliant Energy’s at-the-market offering program. Refer to “Results of Operations” for discussion of expected future issuances of common stock from 2025 through 2028.

Long-term Debt - Refer to Note 6(b) for discussion of AEF’s term loan credit agreements and various issuances and/or retirements of long-term debt by Alliant Energy and IPL in 2025. Refer to “Results of Operations” for discussion of expected future issuances and retirements of long-term debt in 2025.

Impact of Credit Ratings on Liquidity and Collateral Obligations -

Ratings Triggers - In March 2025, Standard & Poor’s Ratings Services changed certain Alliant Energy, IPL and WPL credit ratings and outlooks, which are not expected to have a material impact on Alliant Energy’s, IPL’s and WPL’s liquidity or collateral obligations, and the current credit ratings and outlooks are as follows:

Off-Balance Sheet Arrangements and Certain Financial Commitments -A summary of Alliant Energy’s and IPL’s off-balance sheet arrangements and Alliant Energy’s, IPL’s and WPL’s contractual obligations is included in the 2024 Form 10-K and has not changed materially from the items reported in the 2024 Form 10-K, except for the items described in Notes 3,6 and 12.