TRICARE and Medicare: How TRICARE For Life Works

TRICARE For Life requires Part A and Part B

When a military retiree becomes eligible for Medicare (usually at 65), TRICARE coverage transitions to TRICARE For Life (TFL). To keep TFL, you must enroll in both Medicare Part A and Part B. This is the single most important thing to understand: TFL is not a substitute for Medicare — it’s built on top of it. Without Part B, you are not eligible for TRICARE For Life.

How TRICARE For Life pays

TRICARE For Life pays as secondary coverage to Medicare. Medicare pays first for Medicare-covered services, and TFL then picks up most of the remaining cost-sharing — the deductibles and coinsurance Medicare leaves behind. For services covered by both, this combination often leaves you with little or no out-of-pocket cost. TRICARE For Life has no enrollment fee; your main recurring expense is the Medicare Part B premium, which you must keep paying to stay eligible.

What happens if you skip Part B

Skipping Part B to avoid the premium is a costly mistake for a TRICARE retiree. Because TFL requires Part B, dropping or delaying it can mean losing TRICARE coverage entirely. On top of that, if you enroll in Part B later you may owe a lifelong late-enrollment penalty (10% for each full 12 months you went without it). The safest path is to enroll in Part B during your Initial Enrollment Period around your 65th birthday. Our turning 65 guide explains how to enroll on time and avoid gaps.

A note on CHAMPVA

CHAMPVA, the VA health benefit for certain spouses and dependents, follows a similar rule: Medicare-eligible beneficiaries generally need both Part A and Part B, and CHAMPVA coordinates as secondary coverage in most situations. If you have CHAMPVA, confirm your specific requirements before deciding on Part B.

Bottom line for TRICARE retirees

Enroll in Part A and Part B on time, keep paying the Part B premium, and TRICARE For Life will wrap around Medicare to keep your costs low. This is different from how VA health care works — compare the two in our guide on VA benefits and Medicare, or return to the Veterans and Medicare hub.

A licensed advisor can confirm your TRICARE and Medicare timing so you don’t accidentally lose coverage — at no cost to you.