MX Energy was founded in 1999 in Louisville, Kentucky before moving their headquarters to Connecticut in 2000. MX Energy's mission was to provide electricity and natural gas service in deregulated energy markets in the United States and Canada. In 2011, MX Energy was purchased by Constellation Energy.

Constellation Energy is one of the largest conglomerates in North America. They operate over 35 power plants in 11 states and are one of the leading competitive suppliers of electricity and natural gas, as well as Baltimore Gas & Electric, their regulated utility in central Maryland.

MX Energy services customers for retail electricity and/or natural gas in the following states: California, Connecticut, Florida, Georgia , Illinois, Indiana, Kentucky, Maryland, Massachusetts, Michigan, New Jersey, New York, Ohio, Pennsylvania, and Texas.