FEHB and Medicare Part B for Federal Retirees
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Last updated
Last reviewed Oct 30, 2026
Start with the FEHB Open Season 2026 checklist for retirees (Nov 9 – Dec 14, 2026).
Short answer: FEHB does not require Medicare Part B (postal retirees in PSHB are different)[9]. Enrolling in Medicare doesn't raise or lower your FEHB premium[7]. Whether Part B is worth its monthly premium is a personal decision; here are the facts OPM gives.
What Part B can add
- Some FEHB plans reimburse Part B premiums, and plans may waive copays, coinsurance and deductibles for services Part B covers[8].
- Some Part B services may be only partly covered by your FEHB plan, such as durable medical equipment, home health care and prosthetics[8].
- In an FEHB HMO, you can go outside the network for Part B services[8].
- Many Medicare Advantage plans offered through FEHB reimburse some or all of the Part B premium; you need Parts A and B to join one[7].
Costs and penalties
- Part A is premium-free for most FEHB enrollees; Part B has a monthly premium, and higher-income people pay more[7].
- If you wait 12 months or more after first becoming eligible, your Part B premium goes up 10% for each 12 months you could have had it, for as long as you have Part B[8].
- Part B premiums come out of Social Security, or out of your annuity if you don't get Social Security[8].
A one-time plan change
When you become eligible for Medicare, you can change to any option of any plan starting 30 days before you become eligible. You can use this event only once[6].
How to enroll
If you get Social Security, you're enrolled in Parts A and B automatically at 65; otherwise sign up with SSA[7][11]. If you delay Part B while still working, your retirement system may need to complete form CMS-L564 so you can use the Special Enrollment Period[8].
More Open Season guides
- FEHB Open Season 2026 checklist for retirees
- How to compare prescriptions and doctors across plans
- The 5-year rule for keeping FEHB in retirement
- 2027 FEHB costs for retirees
- PSHB and Medicare Part B for postal retirees
- Self Plus One vs Self and Family
- Keeping FEHB for a surviving spouse
Frequently asked questions
Is Medicare Part B required with FEHB?
No for FEHB. PSHB (postal) annuitants are different: many must enroll in Part B (OPM).
Does Medicare lower my FEHB premium?
No. OPM says enrolling in Medicare doesn't reduce or increase FEHB premiums.
Sources
- OPM: FEHB Handbook, Annuitants (checked Oct 30, 2026)
- OPM: Medicare and FEHB (checked Oct 30, 2026)
- OPM: Medicare for FEHB annuitants (checked Oct 30, 2026)
- OPM: Postal Service Health Benefits (PSHB) Program (checked Oct 30, 2026)
- SSA: Medicare enrollment (checked Oct 30, 2026)
Retiring within 5 years?
Retiring within 5 years? Book a free 20-minute Open Season review.
General information only, not a plan recommendation. Not affiliated with OPM or any government agency.