Medicare for
Federal Retirees.
Most federal retirees become Medicare-eligible at age 65. Understanding when to sign up, how Medicare coordinates with your FEHB plan, what Part B costs based on your income, and when to delay enrollment without penalty are critical decisions that affect your health coverage for life.
Medicare Parts A, B,
C, and D.
Medicare has four distinct parts — each covering different services, with different costs and enrollment rules. Federal retirees interact with all four, but the decisions around Parts A and B are most critical.
Part A — Hospital Insurance
Free for most federal retirees
What it covers: Inpatient hospital care, skilled nursing facility stays, hospice, and some home health care.
Cost: Free if you or your spouse paid Medicare taxes for 10+ years (or worked in federal service on or after January 1, 1983). If not eligible for premium-free Part A, the 2026 premium is $311 or $565/month depending on years of Medicare-covered employment.
For federal retirees: OPM strongly recommends enrolling in Part A. With most FEHB plans, hospital copayments and coinsurance are waived when you carry both Medicare Part A and a FEHB plan — reducing your out-of-pocket hospital costs significantly.
Part B — Medical Insurance
Income-adjusted monthly premium — requires a decision
What it covers: Physician care, outpatient services, preventive care, durable medical equipment, and some home health services.
Cost: $202.90/month standard 2026 premium — but income-adjusted via IRMAA if your MAGI exceeds set thresholds. Higher earners pay 35–80% of total Part B cost.
For federal retirees: When you carry both Part B and FEHB, Medicare becomes your primary insurer and FEHB becomes supplemental — most FEHB plans waive their deductibles, copayments, and coinsurance. This combination typically reduces total out-of-pocket costs significantly, though you must evaluate your specific plan.
Part C — Medicare Advantage
Private plan alternative to traditional Medicare
What it covers: All benefits Original Medicare covers, often with extras like dental, vision, or drug coverage. Offered by private insurers — typically HMO or PPO structures with network restrictions.
For federal retirees: If you enroll in Medicare Advantage Part C, FEHB becomes redundant — but do not cancel your FEHB, suspend it instead. Call OPM at 1-888-767-6738 to get a suspension form. Suspension allows you to reinstate FEHB in a future Open Season if the MA plan doesn't work out. Canceling FEHB is permanent.
Part D — Prescription Drugs
Usually not needed — FEHB drug coverage is comparable
What it covers: Outpatient prescription drugs through private plans with a monthly premium based on income.
For federal retirees: Most federal employees do not need to enroll in Part D separately — all FEHB plans include prescription drug benefits that are at least equal to the standard Medicare prescription drug coverage. If you have limited income, however, Medicare's Low-Income Subsidy (Extra Help) program may be worth investigating through SSA at 1-800-772-1213.
How Medicare works
alongside your FEHB plan.
When you sign up for Medicare and are retired, your FEHB coverage becomes supplemental — Medicare pays first, then your FEHB plan picks up the difference to the extent outlined in your plan's brochure (typically Section 9).
Part A only vs. Parts A + B
Part A only: FEHB remains your primary coverage for physician and outpatient care. Medicare Part A is primary only for hospital care. This is a common choice for those who want to keep monthly costs lower while still getting hospital protection.
Parts A + B: Medicare becomes primary for both hospital and medical care. Most FEHB plans waive their deductibles, copayments, and coinsurance when you have both Part A and B — making this combination very cost-effective for retirees who use medical services regularly.
If your spouse is under age 65, their primary provider remains your FEHB plan until they turn 65.
When you don't have Medicare and your doctor's billing
If you choose not to enroll in Medicare at age 65, most FEHB plans still limit their payments for inpatient hospital and physician care to what Medicare would have paid. Your providers cannot charge more than the Medicare-approved rate. Outpatient hospital and non-physician care are not covered by this limitation — regular FEHB plan benefits apply.
Should I enroll in Medicare?
OPM recommends applying for Medicare benefits 3 months before turning age 65. Here is the general guidance:
Part A — always enroll if it's free
If you qualify for premium-free Part A (which most federal retirees do), enroll. It reduces your out-of-pocket hospital expenses and your FEHB plan's costs — which can help keep FEHB premiums lower over time. There is no reason to decline free Part A.
Part B — evaluate the premium against your expected usage
At $202.90/month standard premium, Part B requires a personal cost-benefit analysis. Key question: will the copayments and deductibles waived by your FEHB plan (when you carry Part B) exceed the monthly premium? For most retirees who regularly see doctors, the answer over time is yes.
OPM recommends reviewing the information and making an individual decision. Consider lower-cost FEHB plans that work well with Medicare — some plans become dramatically more affordable once you add Part B.
Part B delay penalty — when you can delay without penalty
When you can delay Part B without penalty
Still working at 65 (federal or other employer): You can delay Part B without penalty while covered under an employer's active health plan. Enroll within 8 months of leaving that employment or losing employer coverage.
Retired and covered under a working spouse's employer plan: You can delay while covered as a dependent under a working spouse's employer plan. Enroll within 8 months of the spouse leaving employment or losing coverage.
Switching FEHB to a federally employed spouse: This keeps your premiums non-taxable and allows you to delay Part B enrollment without penalty.
Retirees whose FEHB premiums are taxable (unlike active employees) and who start a business or work for an employer that doesn't provide primary health coverage will be penalized if they fail to take Part B at 65.
IRMAA — income-adjusted Part B & D premiums
Part B and Part D premiums are determined by your Modified Adjusted Gross Income (MAGI) from 2 years prior (the most recent IRS return available). Higher earners pay an Income Related Monthly Adjustment Amount (IRMAA) on top of the standard premium.
How IRMAA works
For most beneficiaries, the government pays approximately 75% of the Part B premium; beneficiaries pay the remaining 25% (the standard $202.90/month in 2026). Higher-income beneficiaries pay 35%, 50%, 65%, or 80% of the total Part B cost instead.
MAGI = your household's Adjusted Gross Income plus any tax-exempt interest income (Lines 11 and 2a on IRS Form 1040 in recent tax years). If your income drops significantly due to retirement or a life event, you can request an IRMAA adjustment using Form SS-44 filed with Social Security.
Signing up for Medicare
If you receive Social Security
You will be automatically enrolled in Medicare Parts A and B and should receive your Medicare card three months before your 65th birthday. If you want to decline Part B, follow the instructions that come with your enrollment package.
If you do not receive Social Security
You have a 7-month Initial Enrollment Period (IEP): 3 months before your 65th birthday, the month of your birthday, and 3 months after. Sign up at medicare.gov under "New to Medicare" (takes about 15 minutes), at your local Social Security office, or by calling 1-800-772-1213.
If you sign up the month you turn 65 or in the last 3 months of your IEP, coverage starts the first day of the month after you sign up.
Withdrawing from Part B after signing up
You can withdraw from Medicare Part B at any time — but doing so has consequences and requires a specific process.
How to cancel Part B
Use Form CMS-1763 — this form is not available online. Contact your Social Security Administration office to complete it. A representative will walk through the consequences with you (including any future penalties) and process the form by phone. Notify your FEHB plan immediately upon canceling Part B, as it will become your primary provider for medical services.
Paying Part B premiums from your CSRS annuity
For retirees not receiving Social Security
If you are eligible for Medicare but not receiving Social Security benefits, you can have Medicare premiums withheld directly from your OPM annuity payment. However, OPM cannot act on a direct request from you or from Social Security — the request must come from the Centers for Medicare and Medicaid Services (CMS). Contact Medicare at 1-800-MEDICARE (1-800-633-4227) to initiate the arrangement. Your local Social Security district office may be able to provide additional guidance.
Medicare claim number suffixes
Your Medicare claim number is your Social Security number followed by a letter suffix that identifies your benefit status. Common suffixes:
| Suffix | Benefit status |
|---|---|
| A | Primary claimant (wage earner) |
| B | Spouse (spouse of retired worker) |
| B1 | Aged husband, age 62 or over |
| B6 | Divorced wife, age 62 or over |
| C1–C9 | Child (minor, student, or disabled child) |
| D | Aged widow, age 60 or over |
| D1 | Aged widower, age 60 or over |
| D6 | Surviving divorced wife, age 60 or over |
| HA | Disabled claimant (wage earner) |
| M | Uninsured — premium health insurance benefits (Part A) |
| T | Enrolled in Medicare but Social Security benefits temporarily delayed |
| TA | Medicare Qualified Government Employment (MQGE) |
| W | Disabled widow |
| WA | Railroad Retirement |
Tricare for Life
Military retirees — sign up for Part B before 65 to keep Tricare
If you are retired military or a military spouse with Tricare, you must sign up for Medicare Part B in the 3 months before turning 65 to continue with Tricare for Life. Missing this window terminates Tricare for Life eligibility.
FEHB and Tricare interaction: Time spent covered under Tricare counts toward the 5-year FEHB enrollment requirement needed to carry FEHB into retirement. You must be enrolled in an FEHB plan at the time of your civilian retirement in order to subsequently suspend it for Tricare.
Civilian retirees who choose Tricare and suspend FEHB can re-enroll in FEHB during any future Open Season if providers stop accepting new Medicare/Tricare patients after a move or other coverage disruption.
Medicare guidance
& further reading.
Medicare.gov, OPM's Medicare FAQ, Social Security guidance, and the fedretire.net four-part series on Medicare and FEHB decisions.