The Federal Employees Health Benefits Program is one of the largest employer-sponsored health insurance programs in the world, covering more than 8 million people. It includes active federal workers, retirees, members of Congress, postal service employees, and their immediate families. The Office of Personnel Management administers the program and contracts with 65 private insurance companies to provide coverage. OPM has oversight authority over these carriers, but the scope of that authority over individual health data is disputed.