Medicare and TRICARE For Life: How They Actually Work Together

TRICARE For Life is Medicare-wraparound coverage for retirees, and it comes with one rule that matters more than any other: if you’re eligible for premium-free Medicare Part A, you need Part B to keep your TRICARE coverage. Here’s how the two programs work together, what they cost, and where Medicare Advantage fits in.

This is a different system from VA health benefits, even though people sometimes assume the two work the same way. If you’re not sure which one applies to you, that distinction matters more than almost anything else in this article.

Questions about your own TRICARE and Medicare timing? Talk with our Medicare team, by phone or video wherever you live. There’s no cost and no obligation.

What TRICARE For Life Actually Is

TRICARE For Life (TFL) is TRICARE’s Medicare-wraparound coverage for military retirees, their eligible family members and survivors who have Medicare Part A and Part B. It doesn’t replace Medicare. It works alongside it, and what it pays depends on who covers the service. For services that both Medicare and TRICARE cover, TFL generally pays what Medicare leaves behind, including Medicare’s deductibles and cost-sharing. For services that only TRICARE covers, TRICARE pays as if it were your only coverage, and TRICARE’s own deductible and cost-shares apply. For services that only Medicare covers, such as chiropractic care, TRICARE pays nothing.

That role is similar to what a Medicare Supplement plan does for civilians, though it isn’t the same thing. There’s no TFL premium and no TFL enrollment fee. Each person needs their own Medicare Parts A and B: TFL coverage doesn’t extend to family members who don’t have Medicare.

The Main Rule: You Need Both Part A and Part B, With a Few Exceptions

If you’re a retiree, a family member of a retiree, a survivor or another eligible beneficiary, and you’re eligible for premium-free Part A, you need Part B to keep your TRICARE coverage, including your TRICARE pharmacy benefit. TRICARE’s own wording is that in most cases you must have Medicare Part B to keep TRICARE. Failing to enroll in Part B when you first become eligible, dropping it, or letting your Part B premium go unpaid all mean losing TRICARE coverage until Part B is back in place.

The exceptions are real, though. If neither you nor your spouse (including a former or deceased spouse) is eligible for premium-free Part A, you don’t need Part B. You keep TRICARE Prime (if you live in a Prime Service Area) or TRICARE Select instead of moving to TFL, and you update your DEERS record at a Uniformed Services ID card office with your Social Security Notice of Award or Notice of Disapproved Claim. Active duty service members and their families, and people enrolled in TRICARE Reserve Select, TRICARE Retired Reserve, TRICARE Young Adult or the Uniformed Services Family Health Plan, follow different rules too. TRICARE is the authority on which situation applies to you.

How the Coordination of Benefits Actually Works

With Original Medicare, Medicare pays first for anything both programs cover, and TFL pays second. For services both cover, TRICARE says you’ll generally have no out-of-pocket costs, and the claim crosses over from Medicare to TRICARE automatically, so in most cases you never file a form. Sometimes you do need to file your own claim, for example if TRICARE is your primary insurance, Medicare doesn’t cover the service, or you have other health insurance. TFL even covers the Medicare Part B deductible when the service is covered by both programs.

One exception: if you or your spouse is still working and has an employer plan based on current employment, that plan generally pays first, Medicare second and TRICARE last when the employer has 20 or more employees. With fewer than 20 employees, Medicare pays first, the employer plan second and TRICARE last. If you delay Part B because of that coverage, TFL doesn’t apply and TRICARE won’t act as second payer to the employer plan.

TRICARE also has a catastrophic cap, $3,000 per family per calendar year in 2026. It applies only to TRICARE-covered costs when TRICARE is paying as the primary or only payer, such as for care Medicare doesn’t cover. It doesn’t cap your Medicare cost-sharing or services that neither program covers, and TRICARE posts the current figure on its cost chart.

What TFL Actually Costs

There’s no TFL premium and no TFL enrollment fee. Your required monthly cost is your Medicare Part B premium, currently $202.90 a month for the standard amount and higher with a higher income, plus the Part A premium if you’re not eligible for premium-free Part A and choose to buy it. You may also pay TRICARE pharmacy copays, and when TRICARE is the only payer for a service, TRICARE’s own deductible and cost-shares apply.

That’s a different cost structure than a civilian retiree comparing Medicare Advantage premiums against Medicare Supplement premiums, since TFL is wraparound coverage with no premium attached to it specifically.

Prescription Drugs: Why You Probably Don’t Need a Separate Part D Plan

TRICARE’s pharmacy program is considered creditable prescription drug coverage under Medicare’s rules, which means you don’t need Medicare Part D to have prescription coverage, and you won’t face a Part D late enrollment penalty as long as you don’t go 63 days or more in a row without creditable drug coverage. Keep in mind that your TRICARE pharmacy options depend on Part B: if you don’t enroll in Part B, you can only fill prescriptions at military pharmacies.

You’re not locked out of Part D. You can join a Part D plan during your Initial Enrollment Period or each year from October 15 to December 7, and TRICARE then pays second after the Part D plan for medications both cover. Some people choose a separate Part D plan if it covers a specific medication better than the TRICARE formulary. (If you’re in a Medicare Advantage HMO or PPO, you generally can’t add a stand-alone Part D plan. You’d choose a Medicare Advantage plan that includes drug coverage instead.) If you involuntarily lose TRICARE drug coverage, Medicare gives you a Special Enrollment Period, lasting two full months after the month you lose it, to join a Part D plan or a Medicare Advantage plan with drug coverage. Medicare also gives you a Special Enrollment Period to drop a Part D plan, or a Medicare Advantage plan that includes drug coverage, while you have creditable drug coverage like TRICARE. Note that TRICARE’s pharmacy benefit has not covered weight-loss drugs since August 31, 2025, while Medicare’s temporary GLP-1 Bridge program, which runs through Part D, covers certain ones for eligible people (see our guide to Medicare and weight-loss drugs).

How Medicare Advantage Works With TRICARE For Life

Some TRICARE-eligible retirees choose a Medicare Advantage plan instead of Original Medicare, and you can keep TRICARE For Life when you do. A Medicare Advantage plan includes both Part A and Part B, so enrolling in one doesn’t cost you TRICARE eligibility as long as you keep paying your Part B premium. Medicare Advantage becomes your primary coverage, and TFL remains the second payer for TRICARE-covered services.

One practical difference is worth knowing before you choose. With Original Medicare, claims cross over to TRICARE automatically. With a Medicare Advantage plan they don’t, and TRICARE says you’ll have to file claims to be reimbursed for TRICARE-covered services. TRICARE can reimburse the copayments and coinsurance you paid for services TRICARE covers, but not your plan’s premium, and never more than TRICARE would have paid on its own. Claims go to the TFL claims contractor with the provider’s itemized bill and the other documents TRICARE’s claims instructions call for (the claims contractor’s line, 866-773-0404, can tell you what to include for a Medicare Advantage claim). The deadline is one year from the date of service or inpatient discharge in the U.S., and three years for care overseas, so it pays to keep every statement your plan sends. TRICARE’s claims page has the current form and mailing address, and we explain the process in TRICARE For Life with a Medicare Advantage plan.

TRICARE’s regulations also tie reimbursement to following your plan’s rules. They exclude costs tied to unauthorized out-of-system care, or care obtained in circumstances that lead your plan to deny or limit coverage, and they limit TRICARE’s payment to what it would have paid had the plan covered the care. TRICARE also says that if your other plan denies a claim for failure to follow its rules, TRICARE may deny the claim too. That’s why the type of plan matters, and why it’s worth asking what happens before you go out of network, not after.

What a Medicare Advantage PPO Can Add for TRICARE Retirees

For many TFL beneficiaries, Original Medicare plus TFL already leaves very little out of pocket, with no network to work within and no claims to file. So the real question isn’t which option covers more. It’s what a Medicare Advantage plan would add that you’d actually use. For TRICARE retirees, three things are worth a look:

• Dental, vision and hearing. TRICARE doesn’t cover routine dental care, routine eye exams or hearing aids for retirees on TFL. Retirees can buy dental and vision coverage separately through FEDVIP, and some military clinics sell hearing aids at a reduced price through the Retiree-At-Cost Hearing Aid Program. KFF’s analysis of 2026 plans found that 98% or more of individual plans offered some dental, some vision and some hearing coverage (each at 98% or more), but the benefits often come with limits, such as preventive-only dental in some plans, yearly dollar caps and provider networks, so check the details of each plan you’re considering for 2027.
• A lower Part B premium. Some Medicare Advantage plans reduce the Part B premium you pay. Medicare says some plans “may help pay all or part of your Part B premium,” KFF calls it a Part B rebate, and it’s sometimes marketed as a “giveback.” Because you have to keep Part B to keep TFL, a plan that lowers that premium reduces the cost of something you were paying anyway. It usually shows up as a smaller Part B deduction from your Social Security payment. It isn’t common, though. KFF’s analysis of 2026 plans found that nearly one-third (32%) of individual plans offered one, the amount is small for most enrollees, it isn’t available in every area, and it can change every year. The reduction is paid for from the same rebate that funds a plan’s other extras, so a plan with a larger reduction may offer less elsewhere.
• More room to see out-of-network providers. A PPO covers out-of-network providers, at higher cost-sharing, while an HMO generally covers only in-network care, apart from emergency care, urgent care when you’re out of the area, and temporary out-of-area dialysis. That gives a PPO more flexibility if you want to keep doctors who aren’t in the plan’s network, though an out-of-network provider has to agree to treat you and can’t have opted out of Medicare.

That last point comes with an important caveat. The out-of-network coverage comes from the Medicare Advantage plan, not from TRICARE. TRICARE doesn’t promise to pay the extra cost of going out of network. Its regulations exclude costs tied to unauthorized out-of-system care, or care obtained in circumstances that lead your plan to deny or limit coverage, and limit TRICARE’s payment to what it would have paid had the plan covered the care. We found no TRICARE statement that it pays a PPO’s out-of-network difference, so don’t assume it will. If you’re counting on it, get an answer in writing from the TFL claims contractor first.

There are tradeoffs on the other side, too: a provider network to stay inside (a PPO has one too, with lower costs in network), prior authorization rules (KFF found that 99% of Medicare Advantage enrollees in 2026 were in plans that require it for some services), the claims-filing step described above, and plan benefits, networks and premiums that can change every year. Neither path is wrong. Someone who wants maximum simplicity often does best with Original Medicare and TFL. Someone who wants dental, vision and hearing benefits built in, and doesn’t mind the extra step, may prefer a Medicare Advantage plan.

Going back to Original Medicare is straightforward on the TRICARE side. TFL is automatic whenever you have Parts A and B, with no application and no health questions, so returning to Original Medicare doesn’t require a Medigap application. You can switch during the Medicare Advantage Open Enrollment Period (January 1 through March 31, one change only) or during the fall Open Enrollment Period (October 15 through December 7, effective January 1). See our guide to switching back to Original Medicare and how the enrollment period works.

Plan choice also affects your drugs. Most Medicare Advantage plans include drug coverage, and plans without it are a minority (about 11% of individual plans for 2026, since KFF found that 89% include drug coverage), so check what’s offered where you live. If you pick a plan without drug coverage, TRICARE remains your drug coverage, though you generally can’t add a stand-alone Part D plan. If you pick a plan with drug coverage included, that plan becomes your primary drug coverage and TRICARE pays second, and TRICARE Pharmacy Home Delivery is generally unavailable when you have other coverage with a drug benefit, so compare the plan carefully against what TRICARE already gives you.

Want help comparing a Medicare Advantage plan with staying on Original Medicare and TFL? Talk with our Medicare team. We’ll walk through your doctors, your prescriptions and your TRICARE situation with you, with no cost and no obligation.

Enrollment: There’s Nothing Extra to Sign Up For

You don’t separately apply for TRICARE For Life the way you would a Medigap plan. Coverage starts automatically, the first day Medicare Part A and Part B are both in effect, as long as your information in the Defense Enrollment Eligibility Reporting System (DEERS) is accurate and current. That last part is worth double-checking, especially after a marriage, divorce or any change in a dependent’s status. DEERS is what confirms your eligibility, and outdated information there can cause problems with claims, billing and authorizations. You can update your contact information with DEERS by phone at 1-800-538-9552, but marriage, divorce and dependent changes are made by the sponsor at a Uniformed Services ID card office.

Timing Matters More Than It Seems

Because TRICARE eligibility depends on having Part B in place, and because a gap in Part B means a gap in TRICARE coverage, this isn’t a decision worth putting off. If you’re eligible for premium-free Part A, aim to enroll in Part B well before your 65th birthday month. Starting early in your Initial Enrollment Period gives you the best chance of an uninterrupted transition with no coverage gap on either side. TRICARE’s own published guidance gives slightly different cutoffs on different pages, so the safest approach is to sign up as early as your Initial Enrollment Period allows. Our post on turning 65 on TRICARE lays out the timeline step by step.

If You Also Have VA Benefits

TRICARE For Life and VA health benefits are separate systems with different eligibility rules, and it’s entirely possible to have some connection to both without them working identically. VA benefits alone don’t require you to enroll in Medicare Part B the way TRICARE does. See Medicare and the Cincinnati VA for how that separate system works, and keep in mind that if you add Part B later, a late enrollment penalty may apply. If you’re not sure which situation applies to you, that’s exactly the kind of thing worth sorting out directly rather than assuming either set of rules applies to your specific benefits.

What Happens If You Ever Lose or Drop Part B

If Part B lapses for any reason, whether a missed premium payment or a deliberate choice, your TRICARE For Life coverage lapses with it until Part B is reinstated. You can re-enroll during the General Enrollment Period (January 1 through March 31), and your Part B and TRICARE For Life coverage then start the first day of the month after you sign up. The Part B late enrollment penalty is generally 10% for each full 12-month period you were eligible but not enrolled, and it lasts as long as you have Part B. This is exactly why keeping a close eye on your Part B premium payments matters more for TRICARE-eligible retirees than it might for someone without that added dependency.

A Typical Situation

Picture a retired service member who’s confused about why a friend, also a retiree, seems to be paying nothing for supplemental coverage while he’s still comparing Medigap plans and premiums. Once the two situations are laid side by side, it becomes clear his friend has TRICARE For Life through his own military retirement, which works as his supplemental coverage with no additional premium beyond Part B. The first retiree doesn’t have that TRICARE eligibility, so a traditional Medicare Supplement plan really is the right comparison for his situation. It’s a good reminder that “what worked for my friend” isn’t always the same starting point. (This is an illustration of a common situation, not an account of one specific client.)

Not Near Cincinnati? You Don’t Have to Be

Our office is in Bethel, Ohio, but military retirees live everywhere, and you don’t have to be near Cincinnati to work with us. We’re licensed in 25 states and talk with military retirees and their families by phone or video wherever they live. If you’re near a major installation, our pages for Kansas, Texas, North Carolina, Virginia, Georgia and Florida cover the local Medicare landscape, and the full list of states is on our Locations We Serve page. We’re an independent agency, not affiliated with TRICARE or the Department of Defense.

Frequently Asked Questions

Do I have to actively enroll in TRICARE For Life?

No. Coverage starts automatically once you have both Medicare Part A and Part B, as long as your DEERS record is current. There’s no separate application the way there is for a Medigap plan.

Can I delay Part B the same way people delay it while still working?

You can, under the same employer-coverage rules that apply to anyone still working, but TRICARE says that if you delay Part B you won’t be covered by TFL, and TRICARE won’t act as second payer to your employer plan. To have TRICARE when the employer coverage ends, sign up for Part B during your Special Enrollment Period. See what to do with Medicare if you’re still working past 65 for how that timing works.

Do I need a Medicare Supplement plan if I have TRICARE For Life?

Often not. TRICARE For Life provides wraparound coverage with no TFL premium, which is why many TFL-eligible retirees don’t need a separate Medigap plan, and TRICARE suggests evaluating your own needs.

What if my DEERS information is out of date?

You can update your contact information by calling 1-800-538-9552. For a marriage, divorce or a change in a dependent’s status, the sponsor needs to visit a Uniformed Services ID card office. Outdated DEERS information is one of the more common reasons TRICARE coverage doesn’t line up the way someone expects.

Is there a cost to talk through how this fits with the rest of my Medicare planning?

No. There’s no cost and no obligation to walk through your specific TRICARE and Medicare situation with us, whether you’re newly eligible or have had both for years.

What happens to my TRICARE Prime or Select coverage when I turn 65?

If you’re eligible for premium-free Part A, you need both Medicare Part A and Part B to keep your TRICARE benefits, and TRICARE For Life takes over automatically on the day both are effective. If neither you nor your spouse (including a former or deceased spouse) is eligible for premium-free Part A, you keep TRICARE Prime (in a Prime Service Area) or TRICARE Select past 65 without Part B. See turning 65 on TRICARE for the timeline.

Does TRICARE For Life work if I live overseas?

You still need Medicare Part B to stay eligible, even though Medicare generally doesn’t cover care abroad. Overseas, where Medicare doesn’t pay, TRICARE For Life becomes the primary payer for TRICARE-covered services.

Do I have to file my own claims if I choose a Medicare Advantage plan?

Yes. TRICARE says Medicare Advantage claims don’t cross over, so you file a claim with the TFL claims contractor to be reimbursed for TRICARE-covered services. In the U.S. the deadline is one year from the date of service or inpatient discharge. See TRICARE For Life with a Medicare Advantage plan for what that looks like.

Will TRICARE pay for out-of-network care if I have a Medicare Advantage PPO?

Not as a rule. A PPO’s out-of-network coverage comes from the plan. TRICARE can reimburse copayments for TRICARE-covered services, but its regulations exclude costs tied to unauthorized out-of-system care or care that leads your plan to deny or limit coverage, and limit TRICARE’s payment to what it would have paid had the plan covered the care. We found no TRICARE statement that it pays a PPO’s out-of-network difference. Get an answer in writing from the TFL claims contractor before relying on it.

Can a Medicare Advantage plan lower my Part B premium?

Some plans do (Medicare says some plans “may help pay all or part of your Part B premium,” and it’s sometimes marketed as a “giveback”). Whether a plan offers one, and how much, varies by plan and county and can change each year, so ask for it by name when you compare plans. You still need to keep Part B to keep TRICARE For Life.

Have TRICARE For Life and questions about how it fits with your Medicare enrollment? Talk with our Medicare team, in person near Cincinnati or by phone or video anywhere in our 25 licensed states. There’s no cost and no obligation.