TRICARE East vs TRICARE West
TRICARE East and TRICARE West are the two U.S. regional networks that deliver the same TRICARE Prime and TRICARE Select benefits. Two different contractors run them: Humana Military in the East region and TriWest Healthcare Alliance in the West.
Every guide we write on TRICARE regions starts from the same point readers get wrong. The region changes who administers your network. It does not change what your plan actually costs.
How TRICARE Assigns Your Region
Your TRICARE region is assigned automatically by the Defense Health Agency from the ZIP code on your address of record in the Defense Enrollment Eligibility Reporting System (DEERS). You do not pick East or West the way you pick a plan type. The region follows wherever you live.
States generally sort into one region or the other. A handful of states split between the two, so two beneficiaries in the same state can carry different regional assignments depending on which part of the state they live in.
A Permanent Change of Station (PCS) move that crosses the boundary between regions changes your assignment once you update your address in DEERS. An address change that never makes it into DEERS can leave you assigned to a contractor that no longer covers where you live.
Is TRICARE East the Same as TRICARE Select?
No. TRICARE East is a region, and TRICARE Select is a plan type, and the two answer different questions. TRICARE Select is a Preferred Provider Organization (PPO) style plan available to eligible beneficiaries in both the East and West regions, administered locally by whichever contractor covers your address.
TRICARE East describes where you live. TRICARE Select describes which plan you signed up for. Humana Military simply processes TRICARE Select claims for beneficiaries in the East region, and TriWest does the same job for TRICARE Select enrollees in the West.
TRICARE East vs TRICARE West Cost Share
TRICARE cost-shares are set federally by the Department of Defense and are identical nationwide. TRICARE East and TRICARE West cost exactly the same for the same plan and beneficiary category. Enrollment fees, annual deductibles, copayments, and catastrophic caps do not change based on which region administers your care.
A retiree enrolled in TRICARE Prime in Virginia pays the same enrollment fee and copays as a retiree enrolled in TRICARE Prime in California.
What does vary by region is the provider network, referral and prior-authorization processing, and which company's customer service line you call. A network gap or a slower authorization turnaround in one region is a staffing issue at that regional contractor. It is not a sign that one region charges more than the other.
TRICARE East and TRICARE West Plan Options
Both regions offer the same menu of plans: TRICARE Prime, TRICARE Select, TRICARE Reserve Select, TRICARE Young Adult, and the other standard TRICARE plan types. Eligibility for each plan depends on your sponsor's status, your location, and your family situation, not on which region you live in.
The practical difference between your options in the East versus the West comes down to network density. A rural ZIP code in either region can have thinner TRICARE Prime coverage than a ZIP code near a military treatment facility. That gap has nothing to do with which side of the East/West line it falls on.
What Changes When You PCS Across the East/West Line
Moving across the boundary between TRICARE East and TRICARE West changes your day-to-day experience even though your plan and its costs stay the same. Handle these steps in order after a PCS that crosses regions:
- Update your address in DEERS as soon as you have a new address. The DEERS update triggers your regional reassignment automatically.
- Confirm your new regional contractor and set up an account with Humana Military or TriWest, whichever now covers your address.
- Find a new primary care manager (PCM) if you are enrolled in TRICARE Prime, since your old PCM's network does not carry over across the regional line.
- Check whether existing referrals and authorizations transfer. Some do not carry over automatically between contractors, so a referral in progress before your move may need to be reissued.
- Update any Reserve Select or Young Adult enrollment paperwork tied to your prior region, since billing and enrollment records move to the new contractor.
None of these steps changes what you pay. They change who you call and which network directory you search.
TRICARE East vs TRICARE For Life: Not the Same Thing
TRICARE East and TRICARE West are regional networks for beneficiaries under 65 or otherwise not yet Medicare-eligible. TRICARE For Life is a different program entirely: a wraparound to Medicare for retirees and eligible family members who have both Medicare Part A and Part B.
A national contractor processes TRICARE For Life claims, separate from Humana Military and TriWest. A retiree who ages into TRICARE For Life at 65 leaves the East/West regional system altogether.
TRICARE East and TRICARE For Life are separate programs, with separate contractors and separate enrollment rules. Our TRICARE For Life guide covers eligibility, enrollment, and how it works alongside Medicare in full.
Checking Your Own Region and Costs
Confirm your regional assignment and current-year cost-shares directly through TRICARE's own beneficiary tools, rather than assuming last year's figures still apply. Enrollment fees and catastrophic caps update annually.
Our broader TRICARE plans and costs guide lays out the full 2026 fee schedule across Prime, Select, and Reserve Select, if you want the complete picture beyond the East/West split.