I thought TRICARE covered everything — why do I need Medicare too?

TRICARE requires Medicare enrollment at 65. Without Part A and B, you can't use TRICARE For Life — the most comprehensive TRICARE option. Think of it this way: Medicare becomes your primary coverage, and TRICARE fills the gaps.

I already pay for TRICARE through my military retirement — why should I pay for Part B too?

TRICARE For Life has no enrollment fees or premiums beyond what you already pay. But it requires Medicare Part B. The $202.90/month Part B premium (in 2026) gives you access to TFL's wrap-around coverage, which typically results in $0 out-of-pocket costs.

Can I keep using military treatment facilities without Part B?

Yes, but your access to TRICARE For Life benefits outside MTFs ends without Part B. If you only use MTFs and never need civilian healthcare, you might consider this — but most beneficiaries want the flexibility and protection of TFL.

I Have TRICARE and Just Turned 65, Do I Need to Enroll in Part B?

If you're a military retiree with TRICARE approaching age 65, you face a critical decision: You must enroll in Medicare Part B to keep TRICARE For Life coverage. This isn't optional — it's a requirement. Here's everything you need to know to protect your benefits and avoid costly mistakes.

The Short Answer

Yes, you must enroll in Medicare Part B to keep TRICARE For Life.

When you turn 65:

You're automatically enrolled in Medicare Part A (hospital coverage) if you receive Social Security
You must actively enroll in Part B (medical coverage) to maintain TRICARE For Life
If you don't enroll in Part B, you lose TRICARE For Life and must use TRICARE Select (with higher costs)

What Is TRICARE For Life?

TRICARE For Life (TFL) is the TRICARE benefit for military retirees (and their families) who have Medicare Part A and Medicare Part B.

How it works:

Medicare pays first as your primary insurance
TRICARE For Life pays most or all remaining costs as secondary coverage
Result: Often $0 out-of-pocket for covered services

This combination is exceptionally valuable — you get comprehensive coverage with minimal costs.

The Part B Requirement

Without Part B:

TRICARE For Life ends — You can't use TFL without both Part A and Part B
You're limited to TRICARE Select — Which has enrollment fees, copays, and cost-shares
Late enrollment penalties apply — If you delay Part B and enroll later, you'll pay a permanent premium penalty

2026 Part B Costs

The standard Part B premium for 2026 is $202.90/month. Higher earners pay more through the Income-Related Monthly Adjustment Amount (IRMAA):

Individual Income (from 2024 tax return)	Married Filing Jointly	Part B Premium
$109,000 or less	$218,000 or less	$202.90
$109,001–$137,000	$218,001–$274,000	$284.10
$137,001–$171,000	$274,001–$342,000	$405.80
$171,001–$205,000	$342,001–$410,000	$527.50
$205,001–$499,999	$410,001–$749,999	$649.20
$500,000 or more	$750,000 or more	$689.90

The Part B annual deductible for 2026 is $283. Estimate your prescription drug costs to factor into your decision.

When to Enroll in Part B

If You're Already Receiving Social Security

You'll be automatically enrolled in Part A
Part B enrollment is not automatic — watch for your enrollment packet from Social Security
Enroll during your Initial Enrollment Period (IEP): the 7-month window surrounding your 65th birthday

If You're Still Working With Employer Coverage

You may be able to delay Part B without penalty if you or your spouse is actively working and covered through that employer's group health plan.

Important: TRICARE is not considered creditable employer coverage that allows you to delay Part B. You cannot use TRICARE as a reason to postpone Part B enrollment without penalty.

Your Initial Enrollment Period (IEP)

Your IEP is a 7-month window. Check your specific enrollment deadlines →

3 months before your 65th birthday month
Your birthday month
3 months after your birthday month

Example: If you turn 65 on June 15, 2026:

IEP begins: March 1, 2026
IEP ends: September 30, 2026

Best practice: Enroll in the 3 months before your birthday to ensure coverage starts on the 1st of your birthday month.

What Happens If You Miss the Deadline?

If you don't enroll during your IEP and don't have qualifying employer coverage:

Late Enrollment Penalty

10% added to your Part B premium for each 12-month period you were eligible but not enrolled
This penalty is permanent — you pay it for life
Example: 2 years late = 20% penalty = $202.90 + $40.58 = $243.48/month in 2026

Coverage Gap

You can only enroll during the General Enrollment Period (January 1–March 31 each year)
Coverage starts the first of the month after you enroll
During the gap, you have no TRICARE For Life — only TRICARE Select

Special Situations

You're Working Past 65 With Employer Coverage (Not TRICARE)

If you have employer coverage through active employment (you or your spouse), you may delay Part B. When that employment/coverage ends:

You get an 8-month Special Enrollment Period
No late penalty applies
You'll need to provide proof of employment

Your Spouse Has TRICARE

Spouses of military retirees also need Part B to maintain TRICARE For Life when they turn 65. The same rules apply.

You Have VA Healthcare

VA benefits are separate from Medicare. You can use both, but:

VA care doesn't require Part B
TRICARE For Life does require Part B
Many veterans keep Part B for flexibility to use non-VA providers

How to Enroll in Part B

Online

Visit ssa.gov/medicare

Phone

Call Social Security at 1-800-772-1213

In Person

Visit your local Social Security office

Documents you may need:

Social Security number
Proof of citizenship or legal residency
Proof of any employer coverage (if applicable)