The Indiana Municipal Power Agency was created in 1980 by a group of municipally-owned electric utilities. IMPA, called a joint action agency, was formed so these utilities could share power resources, allowing member cities and towns to provide electricity more economically to their customers. The Agency began operations in 1983 with 26 members. Currently, 52 Indiana cities and towns are members of IMPA.

IMPA is a not-for-profit organization focused on providing its members with a power supply that is low-cost, reliable and environmentally responsible.

IMPA member utilities purchase their power requirements through IMPA and deliver that power to the residents and companies in their service territories. Members deliver electric service to approximately 170,000 households, businesses and industries throughout Indiana. Purchasing power through IMPA, instead of purchasing or generating it themselves, helps members save money and keep electric costs as low as possible. Over its history, IMPA has lowered costs for its members by providing power supply options that were not available to individual member utilities.

The Agency focuses on keeping members and their customers satisfied by providing low-cost, reliable service. To meet these objectives, IMPA decides how best to meet its members' energy needs through a mix of its own generating capacity and purchased power. The Agency's active management of power costs and service quality has built IMPA into one of the country's most competitive power providers.