United Health Group is the parent of United Healthcare, one of the largest health insurers in the U.S. It was created in 1977, as United HealthCare Corporation (it renamed itself in 1998), but traces its origin to a firm it acquired in 1977, Charter Med Incorporated, which was founded in 1974. In 1979, it introduced the first network-based health plan for seniors. In 1984, it became a publicly traded company. In 2005, United Health Group purchased Pacificare Health Systems.
