NiSource Inc. is an energy holding company that operates as a fully regulated natural gas and electric utility serving nearly 4 million customers across six states through its Columbia Gas and NIPSCO brands; its core offerings include natural gas distribution via nearly 60,000 miles of pipeline to residential, commercial, and industrial customers in Indiana, Ohio, Kentucky, Pennsylvania, Maryland, and Virginia, as well as electric generation, transmission, and distribution to approximately 500,000 customers in northern Indiana using a mix of natural gas, hydroelectric, wind, coal, and over 3,000 megawatts of total capacity. The company provides these services through six local utilities: Northern Indiana Public Service Co. (NIPSCO), Columbia Gas of Ohio, Columbia Gas of Kentucky, Columbia Gas of Pennsylvania, Columbia Gas of Maryland, and Columbia Gas of Virginia. Founded in 1912 as Northern Indiana Public Service Company and headquartered in Merrillville, Indiana, NiSource employs about 7,700 people and focuses on reliability, sustainability, renewable natural gas integration, and hydrogen blending initiatives. Recent developments include the 2024 completion of a $2.16 billion transaction issuing a 19.9% indirect minority equity interest in NIPSCO to a Blackstone Infrastructure Partners affiliate, with an additional $250 million equity commitment; a 2025 partnership with Quanta Services and Zachry Group via joint venture for combined cycle gas turbine projects starting execution in 2026 and completing by 2032; and the October 2025 re-establishment of a $1.5 billion at-the-market equity issuance program through 2028 to support capital investments.