If you are a military retiree approaching 65, TRICARE For Life is the version of TRICARE that takes over once you become eligible for Medicare. It works by wrapping around Medicare rather than replacing it, and the single most important thing to understand is that keeping it depends on enrolling in Medicare Part B.
What TRICARE For Life is
TRICARE For Life (TFL) is the TRICARE coverage that works with Medicare. When you reach Medicare eligibility, which is generally at age 65, your TRICARE coverage transitions to TFL automatically as long as you meet its requirements. TFL is designed to coordinate with Medicare, picking up where Medicare leaves off rather than standing in for it.
This guide is specifically about TRICARE For Life. It is a separate program from Veterans Affairs (VA) health care, and the rules described here apply to TRICARE, not to VA coverage.
The defining feature of TFL is the requirement to carry Medicare alongside it. Once you are Medicare-eligible, TFL is secondary coverage that sits on top of Medicare, so Medicare has to be in place for the wraparound to function.
Why Part B is required to keep TRICARE
This is the rule that catches the most people off guard. To keep your TRICARE coverage once you become Medicare-eligible, you must have Medicare Part A and Part B. You will lose TRICARE coverage if you do not enroll in Part B, if you drop Part B, or if you fail to pay your Part B premiums. This applies even if you live overseas.
The reason is structural. TFL is built to be secondary to Medicare, so it assumes Medicare is paying first. Without Part B in place, there is no primary coverage for the outpatient and physician services Part B covers, and the wraparound cannot operate. Losing Part B means losing TRICARE along with it.
Because of this, timing your Medicare enrollment matters. For how Medicare enrollment windows work and how to avoid a gap, see Medicare enrollment periods. Enrolling in Part B when you are first eligible keeps your TRICARE coverage continuous.
How TRICARE For Life pays: Medicare first, TFL second
For care that both Medicare and TRICARE cover, Medicare is the primary payer and TFL is the secondary, or wraparound, payer.
In most cases the process is automatic. The provider files the claim with Medicare, Medicare pays its share, and the claim then crosses over to the TFL claims processor. TRICARE pays the provider for TRICARE-covered services. For services that both Medicare and TRICARE cover, you often owe little or nothing out of pocket.
The coordination is what makes TFL valuable. Medicare handles the first layer of payment, and TFL fills in much of what Medicare leaves behind for dual-covered care, which is why beneficiaries frequently have low or no cost-sharing for those services.
Prescription drugs: you do not need Part D
The TRICARE pharmacy benefit is considered creditable prescription drug coverage. Because it is creditable, you do not need Medicare Part D to keep TRICARE, and you can decline Part D without a late-enrollment penalty as long as you keep your TRICARE pharmacy coverage.
There is one thing to watch. If you went 63 or more continuous days without creditable drug coverage, you could face a Part D late-enrollment penalty later. As long as your TRICARE pharmacy coverage stays in place, that gap does not open. For more on how creditable coverage protects you, see Medicare creditable coverage. If you ever want to understand how Part D itself works, see Medicare Part D.
Do you need Medigap or Medicare Advantage?
Generally, no. You do not need a Medigap policy or a Medicare Advantage plan with TFL, because TFL already wraps around Original Medicare. The role that a Medigap policy plays for other Medicare beneficiaries, filling in cost-sharing left by Original Medicare, is largely what TFL already does for you. For background on what Medigap is and who it serves, see Medicare and Medigap.
The key requirement stays the same: keep Medicare Part A and Part B. That is what allows TFL to function as your wraparound coverage.
TRICARE For Life and Medicare at a glance
| Question | Answer |
|---|---|
| Is Medicare Part B required? | Yes. You must have Part A and Part B to keep TRICARE; dropping or not paying for Part B ends your TRICARE coverage, even overseas. |
| Who pays first? | Medicare pays first; TRICARE For Life pays second as wraparound coverage. |
| Out-of-pocket for dual-covered care | For services both Medicare and TRICARE cover, you often owe little or nothing. |
| Do you need Medicare Part D? | No. The TRICARE pharmacy benefit is creditable, so you can decline Part D without penalty while you keep TRICARE pharmacy coverage. |
| Do you need Medigap or Medicare Advantage? | No. TFL already wraps around Original Medicare; the key is keeping Part A and Part B. |
Frequently asked questions
Yes. Once you are Medicare-eligible, you must have both Medicare Part A and Part B to keep your TRICARE coverage. If you do not enroll in Part B, drop it, or fail to pay the Part B premium, you lose TRICARE, even if you live overseas. Enrolling in Part B when you are first eligible keeps your coverage continuous; see Medicare enrollment periods for the timing.
Medicare pays first and TRICARE For Life pays second. For care both programs cover, the provider files with Medicare, Medicare pays its share, the claim crosses over to the TFL claims processor, and TRICARE pays the provider for TRICARE-covered services. For dual-covered services you often owe little or nothing out of pocket.
No. The TRICARE pharmacy benefit is creditable prescription drug coverage, so you do not need Part D and can decline it without a late-enrollment penalty as long as you keep your TRICARE pharmacy coverage. A gap of 63 or more continuous days without creditable drug coverage could trigger a Part D penalty later, which is why keeping your TRICARE pharmacy coverage matters. See Medicare creditable coverage for details.
No. You generally do not need a Medigap policy or a Medicare Advantage plan, because TFL already wraps around Original Medicare and fills in much of the cost-sharing those products are meant to cover. The requirement that matters is keeping Medicare Part A and Part B. See Medicare and Medigap for more on what Medigap does.
Learn More
- What is Medicare? Parts A, B, C, and D explained
- Medicare enrollment periods and late penalties
- Medicare creditable coverage explained
- Medicare and Medigap
If you are a military retiree mapping out how Medicare and TRICARE For Life will fit together, you can find clear, step-by-step guidance at brevy.com.
The information on Brevy.com is for educational purposes only and is not a substitute for professional legal, financial, or medical advice. Rules vary by state and program and change frequently. Always verify with the relevant agency or a qualified professional. Brevy is not a law firm, financial advisor, or healthcare provider.