A plan similar to a civilian Health Maintenance Organization (HMO) that provides the lowest out-of-pocket cost, in return for the requirement that enrollees use only doctors, hospitals and other health care providers who are part of the TRICARE network.

Enrollees are assigned a Primary Care Physician, known generally as a "Gatekeeper" who supervises all medical care and is the one who authorizes referrals for specialty care.

Enrollees are charged an annual enrollment fee of $230 per person or $460 per family and are charged pre-established co-payments depending on the type of medical care received.

TRICARE STANDARD is the name for the health care option formerly known as CHAMPUS (Civilian Health and Medical Program of the Uniformed Services).

With TRICARE STANDARD, eligible beneficiaries have the greatest flexibility in choosing a health care provider and the government will pay a percentage of the cost. It is chosen most often by individuals and families who have established relationships they wish to maintain with civilian physicians.

TRICARE EXTRA Is the Preferred Provider Option (PPO). It offers choices of civilian physicians and specialist from a network of health care providers. It is chosen by individuals and families whose regular physician is a member of the network or who live too far away from a military hospital.

As with TRICARE STANDARD, the government shares the costs of health care. For using this network of preferred physicians and specialists, the government will pay an additional 5% of medical costs incurred (85% for dependents of active duty members and 80% for retirees).

Beneficiaries are free to switch back and forth among providers by using TRICARE STANDARD or TRICARE EXTRA.