The group health insurance program for Federal employees; the largest employer-sponsored contributory health insurance program in the world. It is voluntary for the employees; about 80 percent of those eligible being covered. At present it covers 8.8 million persons—2.8 million Federal employees and annuitants and their 6 million dependents. It was established under the Federal Employees Health Benefits Act of 1959 (P.L. 86-382, codified in chapter 89, title V, U.S. Code), began operation in July, 1960, and is administered by the United States Civil Service Commission. Every employee may choose between two government-wide plans: a service benefit plan administered by Blue Cross and Blue Shield, and an indemnity benefit plan offered by the insurance industry through the Aetna Life Insurance Company. In addition to the two government-wide plans, there are fifteen employee organizations offering indemnity type plans to their members. An additional choice is available to employees residing in certain geographic areas where prepaid group practice plans are in operation. There are now seven Individual practice plans and nineteen group practice plans participating in the program. One of the various different types of plans operating as apart of the FEHB Program is referred to as a FEHB Plan.