A plan similar to an HMO which provides health services for a fixed price, relying on participating primary care physicians to serve as "gatekeepers" to control patient access to institutional services and specialty care. The primary care physician determines the patient's need for specialty care and any resulting referrals.

A group of primary care providers that are linked in some fashion. It may range from a loose association of physicians in a geographic area with a limited sharing of overhead, patient referral, calls, etc. to a more structured association such as commonly owned satellite clinics.

A group of doctors serving as primary care doctors.