Gateway Health Plan opens doors to health care coverage. Gateway Health Plan company provides managed health care services (as an HMO) to Pennsylvania residents. Its Medicaid HMO serves some 225,000 eligible recipients. In addition, the company serves 24,000 members who qualify for both Medicare and Medicaid assistance through its Medicare Assured special needs program. Gateway's service area covers about 27 counties throughout Pennsylvania. The company's services include primary care, dental, prescriptions, disease management, and mental health services. Gateway, an affiliate of Highmark, was founded in 1992 as an alternative to the Department of Public Welfare's Medical Assistance Program in Pennsylvania.