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TRICARE For Life and Medicare: How They Work Together

By Brian Monahan Updated October 3, 2026

Reviewed October 3, 2026. When you become eligible for Medicare, TRICARE For Life (TFL) becomes your TRICARE coverage, but only if you have both Medicare Part A and Part B. Medicare pays first for services both programs cover, and TFL pays second, so most people owe little or nothing out of pocket for covered care. There’s no TFL enrollment fee, but you must pay the Medicare Part B premium.

Quick answer: To keep TRICARE at 65 (or when you get Medicare because of a disability), enroll in Medicare Part A and Part B. TFL starts automatically on the first day both are in effect. You don’t need Medicare Part D, because TFL beneficiaries keep the TRICARE Pharmacy Program. Active duty family members are the main exception to the Part B requirement.

What TRICARE For Life is

TRICARE For Life is Medicare-wraparound coverage for TRICARE-eligible people who have Medicare Part A and Part B, according to TRICARE.mil. It works much like a supplement: Medicare is your primary coverage, and TFL pays the remaining Medicare cost-sharing for services both programs cover. TFL is worldwide, and when you travel outside the U.S. and its territories, where Medicare doesn’t pay, TRICARE becomes the primary payer.

Do you need Medicare Part B to keep TRICARE?

Yes, in most cases. TRICARE says you only need Medicare Part A and Part B to have TFL coverage. If you’re entitled to premium-free Part A and don’t have Part B, you generally lose TRICARE coverage. The TRICARE newsroom notes that this requirement doesn’t apply to active duty family members or to people enrolled in the US Family Health Plan continuously since October 1, 2012.

Delaying Part B without a Special Enrollment Period can also trigger Medicare’s late enrollment penalty, an extra 10% for each full 12-month period you could have had Part B, for as long as you have it (Medicare.gov).

Who pays first: Medicare or TRICARE For Life?

Situation	Who pays first	Who pays second
Service covered by both Medicare and TRICARE (most doctor and hospital care)	Medicare	TFL (usually leaves you little or nothing to pay)
Service covered by TRICARE but not Medicare	TRICARE	You pay TRICARE’s deductible and cost-shares
Service covered by Medicare but not TRICARE	Medicare	You pay Medicare’s deductible and coinsurance
Care outside the U.S. and U.S. territories	TRICARE	You pay TRICARE’s deductible and cost-shares
You also have employer group health coverage	Your employer plan (follow Medicare coordination rules)	Medicare, then TFL last

TRICARE generally pays after all other health insurance except Medicaid and a few supplemental plans. For how Medicare ranks against job-based coverage, COBRA and other insurance, see our Medicare coordination of benefits guide.

What TRICARE For Life costs

No TFL enrollment fee or premium. TFL itself has no enrollment fee (TRICARE.mil).
Medicare Part B premium. You pay it to Medicare. In 2026 the standard premium is $202.90 a month, and higher earners pay more. See the 2026 Part B premium and IRMAA brackets.
Part A. Most people get premium-free Part A based on work history.
Pharmacy copayments. You pay TRICARE Pharmacy Program copayments, which depend on the drug and whether you use home delivery or a retail network pharmacy.

Do you need Part D, Medigap or Medicare Advantage with TFL?

Medicare Part D

No. TRICARE explains that Part D is optional because TFL beneficiaries remain eligible for the TRICARE Pharmacy Program (source). TRICARE pharmacy coverage counts as creditable coverage, so you won’t face a Part D late penalty if you later decide to join a Part D plan.

Medigap

TFL already pays most Medicare deductibles and coinsurance for services both programs cover, so many TFL beneficiaries decide a Medicare Supplement policy would duplicate coverage. Compare your expected costs before paying a Medigap premium.

Medicare Advantage

You can join a Medicare Advantage plan and keep TFL. TRICARE points out the trade-offs: you may pay a plan premium on top of Part B and must usually use the plan’s network. Some veterans choose an Advantage plan for extras like dental or a fitness benefit. If you’re weighing that, read Medicare Advantage HMO vs. PPO and Medicare vs. TRICARE for SilverSneakers.

Step-by-step: moving from TRICARE to Medicare

Check your Initial Enrollment Period. It’s the 7-month window around your 65th birthday month. If you already get Social Security benefits, you’re enrolled in Parts A and B automatically.
Sign up for Part A and Part B if you’re not automatic. Apply through Social Security online, by phone or in person. Don’t decline Part B if you want to keep TRICARE.
Confirm your Medicare start date. TFL begins the first day both Part A and Part B are in effect.
Keep DEERS up to date. TRICARE eligibility depends on your Defense Enrollment Eligibility Reporting System record.
Tell your doctors. Show both your Medicare card and your uniformed services ID card so claims go to Medicare first.
Review pharmacy coverage. Decide whether to stay with the TRICARE Pharmacy Program only, which most TFL beneficiaries do.

Our turning 65 Medicare checklist and guide to signing up for Part B cover the timing in more detail.

Under 65 with Medicare because of a disability

TFL also applies if you’re under 65 and get Medicare because of a disability, ALS or End-Stage Renal Disease. Medicare.gov says you get Medicare automatically after 24 months of disability benefits, or as soon as disability benefits start if you have ALS (Medicare.gov). Keep Part B when it starts so your TRICARE coverage continues. See Medicare for people with disabilities under 65.

Frequently asked questions

Is TRICARE For Life free?

There’s no TFL enrollment fee, but you must pay the Medicare Part B premium ($202.90 a month standard in 2026) to keep TFL, plus any pharmacy copayments.

Does TRICARE For Life replace Medicare?

No. Medicare is your primary coverage for services both cover. TFL pays after Medicare and fills in most of the cost-sharing.

Do I need Medicare Part D if I have TRICARE For Life?

No. TFL beneficiaries keep the TRICARE Pharmacy Program, which is creditable coverage, so Part D is optional.

Can I change from TRICARE Prime to TRICARE For Life?

When you become entitled to Medicare Part A and have Part B, your TRICARE coverage generally becomes TFL automatically. Active duty family members have different rules, so check with TRICARE.

Can I have a Medicare Advantage plan and TRICARE For Life?

Yes. TFL can pay after a Medicare Advantage plan, but you’ll usually pay any plan premium and must follow the plan’s network rules.

What happens if I drop Medicare Part B?

In most cases you lose TRICARE For Life coverage, and you may face a Part B late enrollment penalty if you re-enroll later.

This article is general information, not legal, tax or individual insurance advice. Medicare365 is not affiliated with or endorsed by the U.S. government or the federal Medicare program.