Medicare and TRICARE

What TRICARE for Life is

TRICARE is the health care program for uniformed services members, retirees, and their families. TRICARE for Life is the coverage that generally becomes available to eligible retirees at age 65.

TRICARE for Life is not a substitute for Medicare. It is designed to work with Medicare. The person must generally have Medicare Part A and Part B to use TRICARE for Life. TRICARE then pays after Medicare for covered services.

The program is different from active-duty TRICARE. A person who is still serving or who has a different status should check the specific TRICARE rules. The age-65 retiree path is the one that most often involves Medicare.

A person who is eligible for TRICARE for Life should not treat it as automatic. The person must enroll in Medicare and keep the enrollment current. A lapse in Part B can affect the TRICARE coverage.

Why Part B is required

TRICARE for Life generally requires Part B. A person who delays Part B may lose access to TRICARE for Life, even if Part A is in place. That is a risk that is easy to miss because the person may feel covered by TRICARE alone.

The Part B premium is a cost, but it is also the key to the TRICARE benefit. A person who drops or delays Part B can end up with neither the full TRICARE coverage nor Medicare Part B.

A person who delays Part B can also face a late enrollment penalty. The penalty is generally 10 percent of the standard premium for each full 12-month period without Part B, and it is generally permanent.

A person who is still working and has employer coverage may have a special enrollment period. That can allow a delay without a penalty. But the TRICARE rules should be checked separately, because the TRICARE benefit may still require Part B at 65.

How the coordination works

When a person has Medicare and TRICARE for Life, Medicare generally pays first. TRICARE for Life generally pays second. The TRICARE coverage may pay some or all of the costs Medicare leaves behind, depending on the service and the rules.

The person should show both cards when receiving care. The provider should bill Medicare first, then TRICARE. If the provider bills the wrong program first, the claim can be delayed or denied.

A person who uses a military treatment facility should check how the facility bills Medicare and TRICARE. The rules can differ from civilian providers.

A person who travels or lives overseas should check the TRICARE rules for care outside the United States. Medicare generally does not cover care outside the country, and TRICARE may have its own rules.

Drug coverage and Part D

TRICARE provides prescription drug coverage. That coverage is generally creditable for Part D, meaning it is at least as good as standard Medicare drug coverage. The person should confirm the status with the plan notice.

If the TRICARE drug coverage is creditable, the person may be able to delay Part D without a penalty. If it is not creditable, the person may owe a Part D late enrollment penalty later. The penalty is generally 1 percent of the national base beneficiary premium for each full month without creditable coverage.

A person who enrolls in Part D while keeping TRICARE should check how the two plans coordinate. In most cases, a person would not use both as primary drug coverage, but the costs and the formulary should be compared.

A person who loses TRICARE drug coverage may have a special enrollment period for Part D. The person should keep the notices and the dates.

Cost and access

TRICARE for Life can reduce the cost of care after Medicare, but it is not free. The person still pays the Part B premium, and TRICARE may have copays or cost-sharing for some services.

A person who uses military providers may have a different experience than a person who uses civilian providers. The person should check the network and the referral rules before receiving care.

A person who is comparing TRICARE for Life with a Medicare Advantage plan should check the networks, the drug formularies, and the travel rules. TRICARE for Life generally works with Original Medicare, not with Medicare Advantage.

A person who is considering a Medicare Advantage plan should ask whether the plan works with TRICARE. In many cases, the combination is not the same as Original Medicare plus TRICARE for Life.

Worked example

Suppose a military retiree turns 65 and is eligible for TRICARE for Life. The retiree enrolls in Part A and Part B during the initial enrollment period. Medicare pays first, and TRICARE for Life pays second.

A second retiree delays Part B because TRICARE feels sufficient. The retiree later learns that TRICARE for Life requires Part B. The retiree enrolls late, faces a penalty, and may have a gap in coverage.

A third retiree is still working and has employer coverage. The retiree checks the special enrollment period rules and the TRICARE requirements. The retiree decides to enroll in Part B at 65 to protect the TRICARE benefit.

The examples show that TRICARE for Life and Medicare are linked. The Part B decision is not just a Medicare decision; it can affect the TRICARE benefit.

Common mistakes

One mistake is assuming TRICARE for Life starts automatically at 65. The person must enroll in Medicare and meet the program rules. A delay can leave a gap.

Another mistake is delaying Part B because TRICARE feels comprehensive. TRICARE for Life generally requires Part B. Without it, the person may lose the TRICARE benefit.

A third mistake is choosing a Medicare Advantage plan without checking how it coordinates with TRICARE. TRICARE for Life is generally designed to work with Original Medicare. The combination should be confirmed before enrolling.

A fourth mistake is forgetting to show both cards at the provider's office. The claim may be sent to the wrong payer and delayed. A simple check at the front desk can prevent the problem. Keep the written answer with the plan documents and review it before each open season. The rules can change, and the TRICARE benefit is too important to leave to memory.

Three honest caveats

1. TRICARE for Life generally requires Part A and Part B. A delay can cost you the TRICARE coverage.
2. Medicare generally pays first and TRICARE pays second. Show both cards to providers.
3. Drug coverage creditable status should be confirmed with the TRICARE notice.

Frequently asked questions

Do I need Medicare Part B for TRICARE for Life?

Generally yes. Eligible retirees must have Part A and Part B to use TRICARE for Life.

Does Medicare or TRICARE pay first?

Medicare generally pays first, and TRICARE for Life generally pays second.

What happens if I delay Part B?

You may lose TRICARE for Life eligibility and face a Part B late enrollment penalty when you enroll later.

Is TRICARE drug coverage creditable for Part D?

TRICARE generally provides creditable drug coverage, but you should confirm with the plan notice.

Can I use TRICARE for Life with Medicare Advantage?

TRICARE for Life is generally designed to work with Original Medicare. Check with TRICARE before choosing a Medicare Advantage plan.

Does Medicare cover care overseas?

Medicare generally does not cover care outside the United States. TRICARE may have its own rules for overseas care.

Source table

Figure	Value used	Official source
TRICARE and Medicare	TRICARE for Life rules	TRICARE MedicareChecked October 28, 2026
Who pays first	Medicare generally	Medicare.gov who pays firstChecked October 28, 2026
Part B enrollment	Social Security application	SSA Medicare sign-upChecked October 28, 2026
Part D costs	Creditable coverage rules	Medicare.gov Part D costsChecked October 28, 2026

What to do next

Confirm your TRICARE for Life eligibility and the Part B requirement before you turn 65. Keep both cards and show them at every visit. The Medicare and VA benefits guide covers another military-related path, and the Medicare initial enrollment period guide explains the timing. If you are worried about a Part B penalty, use the Part B late enrollment penalty calculator.