How Medicare and TRICARE For Life work together

Coordination of benefits — who pays first when you have more than one source of coverage — is the rulebook of TFL. For most retired military, the rules are simple and the outcome is favorable: Medicare pays, TFL wraps, you owe nothing.

The mental model: primary and secondary

Picture two payers stacked in order. Medicare is on top (primary). It looks at every bill first and pays its share. Then the claim drops down to TFL (secondary), which looks at what Medicare paid and what's left, and pays its share. Whatever (if anything) remains is your responsibility.

The four scenarios (memorize these)

Every bill you'll ever see falls into one of these four buckets:

Scenario 1 is by far the most common — almost every routine outpatient visit, hospital stay, and lab test for the typical retiree.

Step-by-step claim flow (Scenario 1)

1. You receive care from a Medicare-participating provider.
2. The provider's billing department submits the claim to Medicare electronically.
3. Medicare reviews and pays its share — typically 80% of the Medicare-approved amount for Part B services, after the annual deductible.
4. The Medicare claim crossover system identifies you as TFL-eligible from your Medicare Beneficiary Identifier and forwards the claim to WPS (Wisconsin Physicians Service), the TFL claims processor.
5. WPS pays the remaining Medicare-approved cost-share — the Part B deductible (if not already met) and the 20% coinsurance.
6. You receive a Medicare Summary Notice (MSN) every 3 months from Medicare and a TFL Explanation of Benefits (EOB) from WPS for each processed claim. Both usually show $0 patient responsibility.

You do nothing in this process beyond presenting your two cards at check-in.

What "Medicare-participating" really means

Three categories of Medicare providers, in order of how good they are for you:

1. Medicare-participating providers (best). They accept Medicare's approved amount as full payment and bill Medicare directly. TFL covers your 20% coinsurance.
2. Non-participating providers. They accept Medicare patients but have not signed the participation agreement. They can charge up to 15% above the Medicare-approved amount (the "limiting charge"). You may owe that extra 15% out of pocket; TFL's payment is based on the Medicare-approved amount, not the limiting charge.
3. Opt-out providers (avoid). They have formally opted out of Medicare for two years at a time. Medicare pays nothing. TFL pays the limited TRICARE allowable amount. You owe the rest of the bill. You and the provider sign a private contract.

Always ask up front: "Do you accept Medicare assignment?" That single question tells you whether you'll owe anything at the visit.

Inpatient claims

The same primary/secondary logic applies to hospital admissions, just with different numbers. Part A pays the bulk of the inpatient bill after the deductible; TFL covers the deductible. For long stays, TFL covers the daily coinsurance starting day 61. Skilled Nursing Facility coinsurance days 21–100 is also covered by TFL.

Pharmacy is separate

The Medicare/TFL coordination flow above is for medical services. Prescriptions follow a different path — through the TRICARE Pharmacy Program administered by Express Scripts. Medicare Part B does cover certain provider-administered drugs (chemotherapy, infusions); those go through the standard medical coordination. But outpatient prescription pills you fill at a pharmacy go through Express Scripts, not through Medicare.

What to do if a claim is wrong

1. Compare the Medicare Summary Notice and the TFL EOB.
2. Confirm the service date, provider, and CPT codes match what you received.
3. If the Medicare side looks wrong, call 1-800-MEDICARE.
4. If the TFL side looks wrong, call WPS at the number on your TFL EOB.
5. Keep documentation; the TFL Handbook explains the formal appeal process.

A practical tip: bring both cards

Show the front desk both your red-white-and-blue Medicare card and your Uniformed Services ID. Some providers' billing software needs both numbers to set up the crossover correctly the first time. Once it's in the system, future visits route automatically.

Continue learning

— suggested by the knowledge graph

Lessons

• What is Medicare? A complete overview for retired militaryA plain-English, handbook-grounded overview of the federal health insurance program for people 65 and older, written specifically for retired service members and their families.
• Understanding Original Medicare (Parts A & B) for veteransExactly what Part A and Part B cover, what they cost in 2026, and why both are required to keep TRICARE For Life.
• Frequently asked questions about Medicare and TRICARE For LifeA quick-reference summary of the questions retired service members and spouses ask most often — with citations to the official source.

Encyclopedia

• Medicare Part AThe hospital insurance side of Original Medicare — covers inpatient stays, skilled nursing, hospice, and some home health.
• Medicare Part BThe medical insurance side of Original Medicare — covers doctor visits, outpatient care, preventive services, and durable medical equipment.
• TRICARE For Life (TFL)The wraparound secondary health coverage for Medicare-eligible military retirees, spouses, and survivors — no premium, no enrollment fee.
• TRICARE Pharmacy ProgramThe DoD prescription drug benefit administered by Express Scripts — your drug coverage if you have TFL.
• WPS (TFL Claims Contractor)Wisconsin Physicians Service — the Defense Health Agency contractor that processes TRICARE For Life secondary claims.
• Medicare AssignmentA provider's agreement to accept Medicare's approved amount as full payment for a covered service.
• Military Treatment Facility (MTF) & Space-Available CareDoD military hospitals and clinics — at 65, retirees can only be seen if appointments aren't needed by active duty or TRICARE Prime enrollees.
• MedicareThe federal health insurance program for people 65+, certain younger people with disabilities, and people with ESRD or ALS.
• Original MedicareMedicare Parts A and B together — the fee-for-service version of Medicare run directly by the federal government.
• TRICAREThe Department of Defense's worldwide health-care program for uniformed service members, retirees, and their families.

FAQs

• Who pays first, Medicare or TRICARE For Life?Medicare pays first for any service it covers. TFL pays second. The claim usually crosses over automatically — you should never pay out of pocket up front.
• Is there an enrollment fee for TRICARE For Life?No. TFL has no enrollment fee and no monthly premium. The only premium you pay is for Medicare Part B.
• Does TFL cover long-term care or a nursing home?No. Medicare and TFL only cover short-term skilled care after a qualifying hospital stay. Custodial long-term care (assisted living, nursing home for daily living help) isn't covered by either.
• Does TFL cover a skilled nursing facility stay?Yes. After a qualifying 3-day inpatient hospital stay, Medicare covers up to 100 days of SNF care and TFL pays the days-21–100 coinsurance.
• I have other insurance besides Medicare and TFL. Who pays first?Order varies. Active-employment group insurance pays before Medicare; retiree coverage like FEHB pays after Medicare and usually before TFL. TFL is almost always last.
• What does TRICARE For Life actually cover?TFL is a wraparound. For services Medicare and TFL both cover, TFL pays nearly all remaining cost-shares. For Medicare-only services, TFL still acts as secondary. For TFL-only services (very few), TFL pays as primary.