Aetna Medicare Supplement Plans have become very popular over the past year. In addition, Aetna has been purchasing smaller insurance companies to expand their footprint in the Medicare marketplace. Two well-known insurance companies Aetna has purchased are Continental Life & American Continental. Both of these companies offer Medicare Supplements at very low prices in some states, including Georgia & Arizona. Aetna was founded in 1853, and is headquarted in Hartford, CT.