How Medicare and TFL split the bill
Your provider files with Medicare, and the claim then crosses over to TRICARE. The TRICARE For Life Handbook (updated August 2026) lays out who pays:
| Type of service | Medicare pays | TRICARE pays | You pay |
|---|---|---|---|
| Covered by both | Medicare-allowed amount | The rest | Nothing |
| Medicare only (for example, chiropractic care) | Medicare-allowed amount | Nothing | Medicare deductible and cost share |
| TRICARE only | Nothing | TRICARE-allowable amount | TRICARE deductible and cost share |
| Neither | Nothing | Nothing | Billed charges |
If Medicare denies care as not medically necessary, TRICARE won't pay either, but if you win a Medicare appeal, TRICARE reconsiders too.
Keeping Part B
TFL requires both Part A and Part B. Part B costs $202.90 a month for most people in 2026 (2027 amounts aren't published yet). Drop it and you lose TRICARE coverage; see do I need Part B to keep TFL.
Using TFL in Oklahoma
- Base pharmacies: Oklahoma has military pharmacies at Tinker Air Force Base (72nd Medical Group), Fort Sill (Reynolds Army Health Clinic), Vance Air Force Base (71st Medical Group) and Altus Air Force Base (97th Medical Group). See using the Tinker or Fort Sill pharmacy.
- Space-available care: some military clinics offer TRICARE Plus primary care to TFL beneficiaries; ask the clinic whether it has openings.
- VA care: VA providers can't bill Medicare, so TFL pays only up to 20% of the TRICARE-allowable amount for non-service-connected care at the Oklahoma City or Muskogee VA medical centers. See VA and Medicare together.
Getting set up at 65
- Sign up for Part A and Part B with Social Security in your Initial Enrollment Period.
- Update DEERS so your record shows Medicare, then get a new uniformed services ID card.
- Use providers that take Medicare. TFL starts automatically once both parts are in effect.
Our guide for veterans, TRICARE and military retirees has more. To talk through whether anything beyond TFL makes sense, from the companies they work with, you can request a call from a licensed insurance agent.
Related questions
Do I need Part D with TFL?
TRICARE pharmacy and Part D.
Do I need Part B to keep TFL?
The rule and its exceptions.
VA and Medicare in Oklahoma
Choosing which to use.
Sources
- TRICARE — TRICARE For Life Handbook (August 2026)
- TRICARE — TRICARE For Life
- TRICARE — Becoming Medicare-eligible
- Tinker Air Force Base — 72nd Medical Group Pharmacy
- Reynolds Army Health Clinic, Fort Sill — Pharmacy
- Altus Air Force Base — Altus AFB pharmacy
- Military OneSource — Vance AFB health care
More questions in this guide
- Can I use VA health care and Medicare together in Oklahoma?
- Can military retirees on Medicare use the pharmacy at Tinker AFB or Fort Sill?
- Do I need Medicare Part B to keep TRICARE For Life?
- Do I need Medicare Part D if I have TRICARE For Life?
Part of the guide: Veterans, Military Retirees and Medicare in Oklahoma · All questions
Frequently asked questions
Do I need a Medicare Supplement (Medigap) with TRICARE For Life?
Usually not. For services both Medicare and TRICARE cover, TFL pays what Medicare leaves, so you generally owe nothing. A Medigap policy would mostly duplicate that. Some people keep other coverage for care neither program covers.
Can I use TFL with a Medicare Advantage plan?
Yes. TRICARE says that if you're in a Medicare Advantage plan, it can reimburse copayments you paid for services TFL covers, though you may need to file those claims yourself. You'd generally use the plan's network.
Who do I call about a TFL claim?
TFL customer service is at 1-866-773-0404, the number in the TRICARE For Life Handbook. For Medicare questions, call 1-800-MEDICARE.
Medicare in your Oklahoma county
Plans, local agents and help, county by county: Oklahoma · Tulsa · Cleveland · Canadian · Comanche · Rogers · Wagoner · Payne · Pottawatomie · Creek · Muskogee · Garfield · Grady · Washington · Logan · Bryan · Le Flore · Carter · Cherokee · McClain · All 77 counties →
