Tricare to medicare is a transition that every military retiree must navigate carefully. When you or your sponsor turns 65, your TRICARE coverage changes significantly. You don’t lose military health benefits entirely. However, you must enroll in Medicare Part A and Part B to keep them. Failing to enroll on time can create gaps in coverage and trigger lifetime penalties.
The standard Part B premium is $202.90 per month in 2026. Missing your enrollment window means paying an additional 10% penalty for every full 12-month period you delayed. That surcharge stays with you for as long as you have Part B. Understanding the tricare to medicare process protects both your coverage and your wallet.
How the Tricare to Medicare Transition Works
Once you become Medicare-eligible at age 65, your existing TRICARE plan ends. It gets replaced by TRICARE For Life (TFL). TFL is a Medicare-wraparound benefit that covers costs Medicare doesn’t pay. The key requirement is straightforward. You must have both Medicare Part A and Part B to qualify.
TFL enrollment is automatic once both Medicare parts are active. There are no enrollment forms or fees for TFL itself. Medicare pays first for covered services, then TFL picks up the remaining TRICARE-covered costs. As a result, most beneficiaries pay little to nothing out of pocket for services covered by both programs. This coordination makes the tricare to medicare shift less disruptive than many retirees expect.
One important distinction applies to Medicare Advantage (Part C) enrollees. If you choose a Medicare Advantage plan, claims do not automatically cross over to TFL. You must file claims separately for TRICARE-covered services. With Original Medicare, this crossover happens automatically.
Enrollment Deadlines and the Tricare to Medicare Timeline
Your Initial Enrollment Period (IEP) lasts 7 months. It starts 3 months before you turn 65, includes your birthday month, and ends 3 months after. Signing up during this window ensures no break in TRICARE coverage. You should begin the process several months early to avoid delays.
Military members and their spouses also qualify for a Special Enrollment Period (SEP). This 8-month window begins while your sponsor is on active duty. It continues for 8 months after retirement or after employer group coverage ends. Enrolling in Part B before your sponsor retires is critical. If you wait until after retirement, you will experience a gap in TRICARE coverage that cannot be backdated.
The table below summarizes key enrollment windows:
| Enrollment Period | Duration | When It Applies |
|---|---|---|
| Initial Enrollment Period (IEP) | 7 months | Around your 65th birthday |
| Military Special Enrollment Period | 8 months | After active duty ends or sponsor retires |
| General Enrollment Period | January 1 – March 31 | If you missed IEP and SEP |
Missing both the IEP and the 8-month SEP forces you to wait for the General Enrollment Period. Coverage then starts the month after you sign up. In most cases, that means months without TRICARE or Medicare coverage. Late enrollment penalties also apply — 10% added to your Part B premium for each full year you were eligible but didn’t enroll.
Prescription Drug Coverage and Avoiding Part D Penalties
TRICARE pharmacy benefits count as creditable prescription drug coverage under Medicare rules. This means you do not need to enroll in a separate Medicare Part D plan to avoid late penalties. As long as you maintain continuous TRICARE pharmacy coverage without a gap of 63 days or more, no Part D penalty applies when you eventually enroll.
If you need proof of creditable coverage, submit a written request to the Defense Manpower Data Center (DMDC) and DEERS Support Office. Keep this documentation accessible. For example, you may need it years later if you decide to add a standalone Part D plan. TRICARE For Life already includes pharmacy benefits, so most military retirees find the tricare to medicare drug coverage transition seamless.
Steps to Protect Your Benefits During the Switch
Start by confirming your Medicare eligibility through the Social Security Administration. You qualify for premium-free Part A if you or your spouse paid into Social Security for at least 40 quarters — roughly 10 years of work. Apply for Medicare Part A and Part B at least 3 months before your 65th birthday or your sponsor’s retirement date.
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Next, verify your DEERS record is current. TFL activation depends on accurate DEERS data showing both your TRICARE eligibility and active Medicare enrollment. Contact your local SHIP program (State Health Insurance Assistance Program) for free, personalized counseling. SHIP counselors specialize in helping beneficiaries navigate the tricare to medicare process and can review your specific situation at no cost.
Finally, if your sponsor has an exception — such as still being on active duty past age 65 — you do not need Part B until that sponsor retires. This exception is narrow but important. Confirm your status with TRICARE directly to avoid enrolling too early or too late.
Frequently Asked Questions
Do I lose TRICARE when I turn 65?
You lose your current TRICARE plan, but you gain TRICARE For Life automatically. The requirement is that you enroll in both Medicare Part A and Part B. Without Part B, your TRICARE coverage ends entirely — including pharmacy benefits.
Can I keep TRICARE For Life if I choose a Medicare Advantage plan?
Yes, TFL still pays as the second payer after your Medicare Advantage plan. However, claims do not cross over automatically like they do with Original Medicare. You must file claims with TFL separately for reimbursement of TRICARE-covered services. Many retirees find Original Medicare plus TFL simpler for this reason.
What happens if I miss the tricare to medicare enrollment deadline?
You will have a gap in coverage until the next General Enrollment Period, which runs January through March each year. Additionally, you face a permanent Part B late enrollment penalty. Typically, this adds 10% to your monthly premium for every full 12-month period you were eligible but did not sign up. Contact Medicare.gov or call 1-800-MEDICARE to explore your options immediately.
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Official Sources & Resources
For verified information on Medicare regulations and consumer protection:
- Medicare.gov (Official Site): medicare.gov
- CMS (Centers for Medicare & Medicaid Services): cms.gov
- NAIC (National Association of Insurance Commissioners): naic.org
- KFF Medicare Research: kff.org/medicare
- Social Security Administration: ssa.gov
Content last reviewed April 2026. If you notice any outdated information, please contact us.