ALLIANT ENERGY CORP (LNT)

Alliant Energy is a regulated investor-owned public utility holding company headquartered in Madison, Wisconsin. Its strategy is built around serving customers and building stronger communities. Its primary focus is regulated electric and natural gas service in the Midwest, provided through two public utility subsidiaries, Interstate Power and Light (IPL) and Wisconsin Power and Light (WPL). Together they serve approximately 1,010,000 electric and 435,000 natural gas customers.

The business is organized into four main parts. IPL generates and distributes electricity and distributes and transports natural gas in select Iowa markets. At December 31, 2025, it served about 505,000 electric and 230,000 natural gas retail customers. It also sells electricity at wholesale in Illinois and Iowa. It exited its Cedar Rapids steam business after year-end. WPL does the same in select Wisconsin markets, serving about 505,000 electric and 205,000 natural gas retail customers and selling electricity at wholesale in Wisconsin. Corporate Services provides administrative services to the group. Alliant Energy Finance (AEF) holds the non-utility businesses: - A 16% interest in American Transmission Company (ATC), an independent transmission-only company, and a 20% interest in ATC Holdco LLC. - Corporate venture investments in energy-technology funds. - A 50% interest in a 225 MW wind farm in Oklahoma. - The 347 MW natural gas-fired Sheboygan Falls Energy Facility, leased to WPL through 2044. - Travero, a supply chain business with short-line rail, a Mississippi River freight terminal, freight brokerage and a rail-served warehouse. - Development-ready industrial sites across its service territories.

Customers are retail and wholesale electricity users and natural gas users in Iowa and Wisconsin. IPL serves incorporated Iowa communities under non-exclusive franchises of up to 25 years, while WPL operates under municipal permits of indefinite duration. Both utilities are regulated: IPL by the Iowa Utilities Commission and WPL by the Public Service Commission of Wisconsin. The Federal Energy Regulatory Commission also has authority over wholesale rates, affiliate transactions and certain other matters. IPL has a retail electric base rate moratorium from October 2025 through September 2029.

Alliant Energy had 2,948 employees at December 31, 2025, and 58% were covered by collective bargaining agreements. Neither IPL nor WPL owns FERC-regulated transmission facilities. They rely mainly on the ITC and ATC transmission systems and participate in the MISO wholesale market. Their generation fleet includes coal-fired stations (such as Ottumwa, George Neal, Louisa, Edgewater 5 and Columbia), natural gas-fired plants (such as Burlington, Prairie Creek, Marshalltown and West Riverside), and 400 MW of solar projects placed in service in 2024. Both utilities are subject to federal, state and local environmental regulation, including evolving EPA greenhouse gas, Clean Air Act and wastewater rules. Prudent compliance costs are eligible for recovery in customer rates.