Preferred provider organization
In health insurance in the United States, a preferred provider organization (PPO), sometimes referred to as a participating provider organization or preferred provider option, is a managed care organization of medical doctors, hospitals, and other health care providers who have agreed with an insurer or a third-party administrator to provide health care at reduced rates to the insurer's or administrator's clients.
Health maintenance organization
In the network model, an HMO will contract with any combination of groups, IPAs (Independent Practice Associations), and individual physicians. Since 1990, most HMOs run by managed care organizations with other lines of business (such as PPO, POS and indemnity) use the network model.