Group Health Plan is a subsidiary division of Coventry Health Care. Coventry Health Care is a managed health care firm based in Bethesda, Md. The company, through its subsidiaries, provides health plans, insurance and workers' compensation services. In addition, Coventry Health Care provides a variety of risk- and fee-based managed care products and services, including HMO, PPO, POS, Medicare Advantage, Medicaid and network rental. The company delivers solutions to various individuals, employer and government-funded groups, agencies and other insurance carriers and administrators. It serves clients in all 50 United States, including the District of Columbia and Puerto Rico. The managed care industry has experienced terrific growth since its beginnings as a California experiment and provides health care services to millions of people. It has helped the industry to substantially restrain medical inflation, reduced unnecessary tests and operations and focus attention on preventive care. Group Health Plan is headquartered in Earth City, Mo., where it employs nearly 300 people.