TRICARE refers to the military health plans for active duty and retired members and their families. As long as all of the member's paperwork is up to date, members are automatically enrolled in TRICARE Standard. This is a health plan that can require up to 20% of payment in certain scenarios. The Extra plan is like an upgraded version of the Standard plan which requires that you pay a maximum of 15%.
The last and best of the three plans is the TRICARE Prime plan. TRICARE Prime is typically only for active duty members. Active duty members can also include members of the Army or Air Force reserves and even those in the National Guard, provided that they are in activated status. If you are on active duty, you can get this plan without having to pay annual enrollment fees or any type of copayment out of your own pocket. This is what most people prefer to use, but the catch is that it is only available in specific areas. If you happen to be in an area that allows this or are in a scenario where you are an eligible family member, you should definitely take advantage of it. In general, family members of inactive personnel will pay more out of pocket for medical services. For instance, there is a fee for the Prime plan for family members.
All of these plans have a few basic things in common. The main thing is that each plan provides you with a primary care manager (PCM). As long as you seek medical attention from your PCM, generally everything is covered by your insurance. It is up to you to seek a referral from your PCM should you need to see a specialist.