Alliant Energy Subsidiaries Secure Up to $5.13B in Low-Cost DOE Loan Guarantees & FFB Facilities

Executive Summary

On October 26, 2026, Alliant Energy Corporation ($LNT) announced that its two primary operating utility subsidiaries, Interstate Power and Light Company (IPL) and Wisconsin Power and Light Company (WPL), entered into material financing agreements under Title XVII of the Energy Policy Act of 2005 with the U.S. Department of Energy (DOE) and the Federal Financing Bank (FFB).

Together, the agreements establish multi-advance term loan facilities totaling up to $5,126,488,000 in debt financing backed by 100% DOE guarantees.

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Facility Breakdown and Key Terms

Feature	Wisconsin Power & Light (WPL)	Interstate Power & Light (IPL)
Max Guaranteed Amount	$1,626,488,000	$3,500,000,000
Borrower Type	Full recourse, senior unsecured	Full recourse, senior unsecured
Final Maturity Date	May 15, 2056	May 15, 2056
Amortization Schedule	4 equal annual installments (2053–2056)	5 equal annual installments (2052–2056)
Interest Rate	U.S. Treasury Rate + 37.5 bps	U.S. Treasury Rate + 37.5 bps
Interest Payment Dates	May 15 and November 15	May 15 and November 15
Availability Window	Through September 15, 2033	Through September 15, 2033

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Key Provisions & Strategic Impact

1. Ultra-Low Cost of Capital: Borrowing at U.S. Treasury rates plus a 37.5 bps spread significantly undercuts prevailing commercial utility debt yields, delivering substantial interest expense savings over the ~30-year life of the loans.
2. Long-Term CapEx Support: Proceeds reimburse up to 80% of eligible project costs across grid resilience, power generation (nuclear, gas, renewables, storage), and transmission infrastructure upgrades through 2033.
3. Customer Rate Relief: The reduced cost of debt directly benefits utility rate cases and customer bill affordability under state utility commissions (PSCW and IUC), lowering regulatory friction for capital deployment.
4. Balance Sheet & Credit: Borrowings are senior unsecured obligations of the respective operating subsidiaries, with parent Alliant Energy having no direct debt obligations or guarantees under the facilities.