Medical Mutual of Ohio has its roots in the formation in Cleveland Hospital Service Association (CHSA) in 1934, CHSA was a precursor to the Blue Cross Association.
Medical Mutual of Cleveland was formed in 1956 and merged with Akron Hospital Service to form Blue Cross Plans, which became affiliated with the Blue Shield system in 1961.
Blue Cross of Northeast Ohio and Blue Shield merged to form Blue Cross and Blue Shield of Ohio in 1984.
Medical Mutual of Ohio later left the the Blue Cross/Blue Shield Association in 1997.
Today the company is a nonprofit managed care company that provides health insurance to 1.6 million members in several midwestern and southern states in the United States.