Hawaii Medical Service Association (HMSA) is Hawaii's largest health insurance company. The not-for-profit company serves some 708,000 members and is an independent licensee of the Blue Cross and Blue Shield Association. Hawaii Medical Service Association's insurance plans include Health Plan Hawaii (HMO), preferred provider plans (PPOs), and traditional indemnity, as well as supplemental Medicare and high-deductable plans. The company serves both employer groups and individual members. In addition to health plans, the company covers dental and vision services and prescription drugs. HMSA also provides wellness, disease management, and health education services. It was formed in 1938.