The Hawaii Medical Service Association (HMSA) is a nonprofit, mutual benefit society founded in 1938. HMSA is the most experienced provider of health care coverage in the state, and is dedicated to helping control Hawaii's health care costs by providing quality, affordable health plans and employee benefit services. HMSA serves approximately 690,000 members -- 500,000 sponsored by employers. HMSA is a member of the Blue Cross Blue Shield Association, an association of independent Blue Cross and Blue Shield plans.