It serves more than 1,000,000 residential, commercial and industrial customers in the states of Ohio, Michigan, Kentucky, New York, Pennsylvania, Indiana, Virginia, Maryland, Texas, California, Illinois and Massachusetts.

In 1986, Marvin White, former CEO of Columbia Gas Distribution Companies, helped found Ohio's choice program.

By 1992, IGS Energy expanded its focus to include natural gas retail marketing directly to end-users.

[5] In 2011, IGS acquired gas and electricity supplier Accent Energy, based in Dublin, Ohio, and its subsidiary Dynowatt.

[10] IGS Energy participates in Natural Gas Choice and provides electric service to residential customers.

In January 2013, IGS Energy CNG Services announced plans to invest $10 million to construct four compressed natural gas refueling stations off Interstate 79 in West Virginia and Pennsylvania.

[15] IGS owns, operates or maintains 20 CNG stations across Ohio, Indiana, West Virginia, Pennsylvania and Wisconsin.