Prepaid Group Health Organizations: Organized systems for providing comprehensive prepaid health care that have five basic attributes: (1) provide care in a defined geographic area; (2) provide or ensure delivery of an agreed-upon set of basic and supplemental health maintenance and treatment services; (3) provide care to a voluntarily enrolled group of persons; (4) require their enrollees to use the services of designated providers; and (5) receive reimbursement through a predetermined, fixed, periodic prepayment made by the enrollee without regard to the degree of services provided. (From Facts on File Dictionary of Health Care Management, 1988)