ALLIANT ENERGY CORP

The liquidity and capital resources summary included in the 2025 Form 10-K has not changed materially, except as described below.

Liquidity Position -At September 30, 2026, Alliant Energy had $26 million of cash and cash equivalents, $596 million ($139 million at the parent company, $300 million at IPL and $157 million at WPL) of available capacity under the single revolving credit facility and no available capacity at IPL under its sales of accounts receivable program at the current limit on cash proceeds.

Capital Structure - The following table shows financial capital structures as of September 30, 2026, as well as an adjusted capitalization structure that Alliant Energy believes is consistent with how a majority of the rating agencies currently view its junior subordinated notes (in millions):

(a)The long-term debt component of Alliant Energy’s financial capital structure includes junior subordinated notes classified as “Long-term debt, net” on Alliant Energy’s balance sheet. The adjusted presentation attributes 50% of the junior subordinated notes to common equity and 50% to long-term debt, to align with the debt-to-capital ratio used by the majority of rating agencies. The non-GAAP adjusted presentation reflecting this treatment is useful and relevant to investors in understanding how management and the rating agencies evaluate Alliant Energy’s capital structure.

Cash Flows -Selected information from the cash flows statements was as follows (in millions):

Operating Activities -The following items contributed to increased (decreased) operating activity cash flows for the nine months ended September 30, 2026 compared to the same period in 2025 (in millions):

Investing Activities - The following items contributed to increased (decreased) investing activity cash flows for the nine months ended September 30, 2026 compared to the same period in 2025 (in millions):

(a)Largely due to higher expenditures for IPL’s gas generation and WPL’s refurbishment of existing wind farms, partially offset by lower expenditures for IPL’s energy storage.

(b)Refer to Note 14 for details of the transfer of gas generation assets from WPL to IPL.

(c)Includes higher cash payments related to cost of removal obligations at IPL and WPL.

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 2026 through 2030 are currently anticipated as follows (in millions), which are focused on adding renewable generation and energy storage projects, dispatchable thermal generation and Liquified Natural Gas (LNG) projects to meet growing customer demand for electricity and natural gas, including expected future data center growth from currently executed electric service agreements, and strengthening the resiliency and reliability of the electric and gas distribution systems. 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. Refer to “Customer Investments” for further discussion of certain key utility business projects impacting construction and acquisition plans, and the related regulatory filings.

Financing Activities - The following items contributed to increased (decreased) financing activity cash flows for the nine months ended September 30, 2026 compared to the same period in 2025 (in millions):

Common Stock Issuances and Common Stock Dividends - Refer to Note 5 for discussion of common stock issuances by Alliant Energy in 2026 and Alliant Energy’s at-the-market offering programs. Refer to “Results of Operations” for discussion of expected future issuances of common stock for the remainder of 2026 through 2030 and common stock dividends in 2027.

Short-term Debt - Refer to Note 6(a) for discussion of Alliant Energy’s term loan credit agreement entered into in 2026.

Long-term Debt - Refer to Note 6(b) for discussion of issuances and/or retirements of long-term debt by Alliant Energy, AEF and IPL in 2026. Refer to “Results of Operations” for discussion of expected future issuances and retirements of long-term debt by the end of 2027.

U.S. Department of Energy (DOE) Loan Guarantee Borrowings - In October 2026, IPL and WPL each entered into a loan guarantee agreement with the DOE. Under the agreements, the DOE may guarantee borrowings of up to $3.5 billion for IPL and up to $1.6 billion for WPL, subject to satisfaction of applicable conditions and requirements. The guaranteed financing is intended to support eligible energy infrastructure projects and could provide lower-cost financing for the benefit of IPL’s and WPL’s customers. No amounts have been borrowed under the loan guarantee agreements.

Impact of Credit Ratings on Liquidity and Collateral Obligations -

Ratings Triggers - In March 2026, Standard & Poor’s Ratings Services changed certain IPL credit ratings, which are not expected to have a material impact on Alliant Energy’s and IPL’s liquidity or collateral obligations. Alliant Energy’s, IPL’s and WPL’s 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 2025 Form 10-K and has not changed materially from the items reported in the 2025 Form 10-K, except for the items described in Notes 3,6 and 12.