Medicare Part B Late Enrollment Penalty: How Federal Retirees Avoid It

How the Penalty Works

The Medicare Part B late enrollment penalty is a permanent surcharge added to your monthly Part B premium. It's calculated at 10% of the standard premium for every full 12-month period you were eligible for Part B but didn't enroll.

For 2026, the standard Part B premium is $202.90 per month. If you were eligible for three full years without enrollment, your penalty would be 30% of $202.90 — an extra $60.87 per month on top of the standard premium, for life. The penalty never goes away. It follows you through every future premium increase, recalculated annually against the new standard rate.

A rough formula: take the number of full 12-month periods you delayed, multiply by 10%, and apply that percentage to the current year's standard premium.

Example: You turned 65 in 2020, were already retired, and chose not to enroll in Part B. In 2026, you decide you want Part B. That's six years of delay, so your penalty is 60% of $202.90 = $121.74 extra per month. Your total monthly Part B premium: $324.64. And that 60% surcharge recalculates upward each year as the base premium rises.

Why Federal Employees Working Past 65 Are Protected

If you're still actively employed in federal service past age 65, your FEHB plan is your primary coverage. Medicare knows this. As long as you have group health coverage based on current employment (not retiree coverage, not COBRA), you can delay Part B without penalty.

This protection is called the Special Enrollment Period (SEP). Here's how it works:

1. You work past 65 with FEHB as your primary plan
2. You retire at any age past 65
3. You get an 8-month window from your last month of active employment to enroll in Part B with no penalty

The key paperwork: submit Form CMS-40B (Application for Medical Insurance) and Form CMS-L564 (Request for Employment Information) to your local Social Security office. The L564 must be completed by your agency's HR department or by OPM, certifying that your FEHB coverage was based on active employment.

The SEP exists specifically for people in your situation — those who had qualifying employer-based coverage that legitimately justified delaying Part B.

The Trap: Retiring Before 65 and Skipping Part B

This is where federal retirees most commonly get stung. You retire at 58 under FERS with 30 years. Your FEHB coverage continues into retirement. You turn 65 and think, "I already have great health insurance — why pay an extra $202.90 per month for Part B?"

That reasoning isn't wrong in the short term. But once you're retired, your FEHB coverage is retiree coverage, not active employee coverage. It doesn't qualify for the Special Enrollment Period protection. If you skip Part B at 65 while already retired, there is no SEP — your Initial Enrollment Period (the 7-month window around your 65th birthday) was your one penalty-free chance.

Miss that window and you face:

• Waiting for the next General Enrollment Period (January through March annually)
• Coverage starting the first day of the month after you enroll
• The permanent 10% per-year penalty on every premium payment going forward

How PSHB Changes the Penalty Calculus for Postal Retirees

Postal employees and retirees transitioned from FEHB to the Postal Service Health Benefits (PSHB) program on January 1, 2025. For postal retirees who retired after that date and were under 64 as of January 1, 2025, Medicare Part B enrollment is mandatory to maintain PSHB coverage.

If a postal retiree declines Part B, PSHB coverage is automatically terminated — permanently. There's no re-enrollment option. So for postal retirees subject to the mandate, the Part B late enrollment penalty becomes irrelevant in one sense (you can't skip Part B without losing all health coverage) but even more critical in another: if you delay enrolling and then need to catch up, you're paying the penalty premium alongside the mandatory Part B premium for the rest of your life.

Postal retirees who retired on or before January 1, 2025, and were not enrolled in Part B as of that date, or who were 64 or older on that date, are exempt from the Part B mandate. The same exemptions apply to retirees with VA health coverage, Indian Health Service eligibility, or permanent foreign residency.

Can You Get the Penalty Removed?

In limited circumstances, yes:

If you had qualifying group coverage and can prove it: If you had employer-based group health coverage during the period you didn't enroll — and you can now provide documentation through CMS-L564 — you may be able to have the penalty removed retroactively. This typically requires an appeal to your local Social Security office.

Medicare Part B Income-Related Premium Adjustment (IRMAA) appeal: This is a different issue. If your IRMAA surcharge (based on 2-year lookback income) doesn't reflect your current income because you've retired, Form SSA-44 can request a recalculation. But SSA-44 doesn't affect the late enrollment penalty — only the income-based surcharge.

For most retirees who simply chose not to enroll: There's no appeal. The penalty stands. CMS treats the decision to skip Part B during an available enrollment period as a permanent choice with permanent consequences.

Timeline: When to Act

If you're approaching any of these milestones, mark the dates:

Still working past 65: No action needed. Your SEP starts when you separate from service. Just don't miss the 8-month window after your last day of active employment.

Planning to retire before 65: No Part B decision yet. Enroll in Part A at 65 (it's free). When you turn 65 as a retiree, you have the 7-month Initial Enrollment Period (3 months before your birthday month through 3 months after) to decide on Part B. If you decline it then, the penalty clock starts.

Already retired and past 65 without Part B: Evaluate whether the wrap-around benefit of FEHB + Medicare Part B is worth the annual premium. If you decide to enroll, the General Enrollment Period runs January 1 through March 31 each year, with coverage starting the first day of the month after you enroll.

The FEHB & Medicare Coordination Guide breaks down the premium math for each major FEHB plan — showing exactly when the Part B wrap-around benefit pays for itself and when it doesn't.

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