Alliant Energy Corporation filed a combined Form 8-K on October 28, 2026, disclosing that its subsidiaries Wisconsin Power and Light Company and Interstate Power and Light Company each entered into DOE loan guarantee agreements and Federal Financing Bank credit facilities on October 26, 2026.

Key Highlights

  • WPL maximum guaranteed loan amount: Advances under the WPL Credit Facility may not exceed $1,626,488,000, according to the filing.
  • IPL maximum guaranteed loan amount: Advances under the IPL Credit Facility may not exceed $3,500,000,000, according to the filing.
  • Availability period: Each borrower may request advances until the earliest of September 15, 2033, reaching the applicable loan cap, or an event of default, the filing states.
  • Final maturity: The scheduled final maturity date for all borrowings under each Credit Facility is May 15, 2056, as disclosed in the filing.
  • Interest rate structure: Each advance will bear interest at the applicable U.S. Treasury rate plus a spread of 37.5 basis points, set by the FFB at the time of the advance.
  • Senior unsecured obligations: All borrowings under both Credit Facilities are described as "full recourse, senior unsecured obligations" of the respective borrowing subsidiary.
  • Parent company position: The filing states that Alliant Energy Corporation "is not a party to, and has no direct obligations with respect to, the Loan Documents."

WPL and IPL Secure DOE-Guaranteed Credit Facilities Through Federal Financing Bank

According to the filing, Wisconsin Power and Light Company ("WPL") and Interstate Power and Light Company ("IPL"), both wholly owned subsidiaries of Alliant Energy Corporation (NASDAQ:LNT), separately entered into loan guarantee agreements with the U.S. Department of Energy on October 26, 2026. Each subsidiary also executed a note purchase agreement and a future advance promissory note with the Federal Financing Bank ("FFB") and the U.S. Secretary of Energy. The agreements were made under the DOE Loan Guarantee Program established under Title XVII of the Energy Policy Act of 2005, as amended.

The filing discloses that proceeds of advances under each Credit Facility must be used to reimburse the applicable borrower for "up to 80%" of "eligible project costs" as defined in the applicable Loan Guarantee Agreement. Eligible projects described in the filing may include energy infrastructure such as nuclear, coal, oil, natural gas, geothermal or hydropower generation facilities, new and upgraded transmission infrastructure, substations, energy storage, and other grid resilience technologies. Each borrower may request advances up to one time per calendar quarter and no more than four times per year. If the first advance to WPL or IPL has not occurred within 18 months of the effective date of the applicable Loan Guarantee Agreement, the DOE may terminate that agreement upon not less than 10 business days' notice, according to the filing.

WPL's outstanding principal is payable in four equal annual installments on May 15, 2053, May 15, 2054, May 15, 2055, and May 15, 2056. IPL's outstanding principal is payable in five installments on November 15, 2052, November 15, 2053, November 15, 2054, November 15, 2055, and May 15, 2056. The filing notes that each advance's interest rate equals the applicable U.S. Treasury rate plus 37.5 basis points, with interest payable on May 15 and November 15 of each year. The FFB Notes allow each borrower to elect to have the applicable U.S. Treasury rate reset periodically by selecting an interim maturity date in its advance request.

What Was Disclosed

Alliant Energy's subsidiaries WPL and IPL entered into separate DOE-guaranteed loan facilities on October 26, 2026, capped at $1,626,488,000 and $3,500,000,000 respectively, to finance eligible energy infrastructure projects, with borrowings maturing by May 15, 2056.