How long does the Part B late enrollment penalty last?

For life, for most people. The penalty applies as long as you have Part B — which for most beneficiaries means the rest of their life. It doesn't 'phase out' or expire. The only ways the penalty stops: (1) you lose Part B (rare), (2) you become eligible for Medicaid in some specific dual-eligible categories that pay Medicare premiums (QMB primarily), or (3) you successfully request equitable relief from CMS in cases of administrative error or mistaken government information.

Can I appeal the Part B late enrollment penalty?

In limited circumstances. You can request 'equitable relief' if your delay was caused by misinformation or error from a federal government employee (e.g., a Social Security representative told you incorrectly that you didn't need Part B). Equitable relief is granted infrequently and requires documentation. Contact your local Social Security office or call 1-800-772-1213 to start the process. For most penalty situations, no appeal pathway exists — Social Security calculates based on enrollment records.

If I had a small employer (under 20 employees), does my coverage count?

No, for Part B SEP purposes. Employer group health plans from employers with fewer than 20 employees don't qualify you for a Part B Special Enrollment Period. The reason: at small employers, Medicare is the primary payer at age 65, and your employer plan is secondary. CMS's rationale is that you should have enrolled in Part B at 65 since you needed it as primary coverage anyway. If you delayed Part B while working at a small employer, late penalties apply when you finally enroll.

Does the Part B penalty apply if I'm only enrolling in Medicare Advantage?

Yes — Medicare Advantage requires you to be enrolled in Parts A and B first. If you delayed Part B without creditable coverage and now want to enroll in an MA plan, you must first enroll in Part B (which triggers the penalty) before the MA plan can take effect. The penalty applies to the Part B premium you continue paying even while enrolled in MA.

How is the penalty calculated if I had creditable coverage for only part of my delay?

Only the months WITHOUT creditable coverage count toward your delay. For example: you turned 65 in January 2022 and didn't enroll in Part B. You had employer coverage from a 20+ employer through July 2023 (creditable). You then went without coverage from August 2023 until enrolling in Part B in January 2026 — that's 30 months of non-creditable delay = 2 full 12-month periods = 20% penalty. The 18 months of creditable coverage are excluded from the calculation. Social Security will request documentation of your creditable coverage period via Form CMS-L564.

Is the Part B late enrollment penalty the same as the Part D late enrollment penalty?

No — they're separate. The Part D late enrollment penalty applies when you delay Part D enrollment without creditable prescription drug coverage. Part D penalty is calculated differently: 1% of the 'national base premium' ($38.99 in 2026) for each month of delay, not just full years. Part D penalty is also permanent. You can have both penalties simultaneously if you delayed both without creditable coverage.

Medicare Part B Late Enrollment Penalty Calculator (2026 Ohio)

On this page

Calculator
How the penalty works
What counts as 'creditable coverage'
Avoiding the penalty (the SEP options)
Real Ohio examples
Common questions

Calculator

Part B Late Enrollment Penalty Calculator

Estimate your monthly Part B penalty if you delayed enrollment. The penalty is permanent — it lasts as long as you have Part B.

When did you become Medicare-eligible? Usually the month you turned 65 (or month 25 of SSDI for disability eligibility).

When did you (or will you) enroll in Part B? Month and year of actual Part B enrollment.

Did you have creditable health and prescription coverage during the gap? Employer plan from a 20+ employer, FEHB, TRICARE, VA Health, or similar.

Your estimated penalty

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Enter your dates above to calculate. Results assume the 2026 standard Part B premium of $202.90/month.

This calculator provides estimates only. Your actual Part B penalty is determined by Social Security based on official records. The 2026 standard Part B premium is $202.90/month; the penalty adjusts annually with the premium.

How the penalty works

The Medicare Part B late enrollment penalty exists to incentivize timely enrollment. The rules:

Penalty rate: 10% of the standard Part B premium for each full 12-month period you delayed Part B after first becoming eligible, while having no creditable coverage. Partial years don't count — you must accumulate a full 12 months of delay to add another 10%.
Permanent: The penalty lasts as long as you have Part B. For most beneficiaries, that means for life. It does not "phase out" over time.
Calculated on the standard premium: The penalty is 10% of the standard Part B premium ($202.90 in 2026) — not 10% of any IRMAA-adjusted premium you might be paying. The dollar amount of the penalty changes annually as the standard premium changes.
Stacks with IRMAA: If you have both an IRMAA surcharge and a late-enrollment penalty, both apply to your monthly premium.
Applied automatically: Social Security calculates and applies the penalty when you enroll in Part B. You don't need to do anything to trigger it; it just shows up in your Medicare premium.

What counts as 'creditable coverage'

The penalty doesn't apply if you had creditable coverage during your delay. Creditable Part B-equivalent coverage means health insurance that provides at least the same coverage as Original Medicare Part B. Common examples:

Employer group health plan from a 20+ employer — coverage based on current employment (yours or your spouse's). The 20-employee minimum matters; smaller employers' plans don't count for Part B SEP purposes.
FEHB (Federal Employees Health Benefits) — federal employee plans count when based on current federal employment.
PSHB (Postal Service Health Benefits) — replaced FEHB for postal workers in 2025; same creditable coverage rules apply.
TRICARE — military health coverage. TRICARE recipients have unique Part B coordination — see your TRICARE handbook.
VA Health — Veterans Affairs medical care typically counts as creditable for Part B SEP purposes when actively used.
Foreign country health system if you lived abroad — qualifies for a Part B SEP upon return.

Does NOT count as creditable for Part B SEP:

COBRA (continuation coverage from a former employer).
Retiree health plans (coverage based on past, not current, employment).
Individual insurance plans purchased on healthcare.gov or directly from carriers.
Short-term medical plans, indemnity plans, or other non-comprehensive insurance.
Medicaid that began after you became Medicare-eligible (timing matters).

COBRA is the most common penalty trap

Many people losing employer coverage at 65 elect COBRA to bridge to retirement, then enroll in Medicare months or years later. COBRA does NOT count as creditable coverage for Part B Special Enrollment Period purposes. By the time COBRA ends and you enroll in Part B, you've accumulated months of delay that count toward the penalty calculation. If you're approaching 65 with COBRA on the horizon, enroll in Part B during your Initial Enrollment Period — don't wait.

Avoiding the penalty (the SEP options)

The two ways to avoid the Part B late enrollment penalty:

Enroll during your Initial Enrollment Period (IEP) — the 7-month window around your 65th birthday. The 3 months before, your birthday month, and the 3 months after.
Use a Part B Special Enrollment Period (SEP) tied to creditable coverage — if you delayed Part B because you had employer coverage from a 20+ employer (yours or your spouse's), FEHB based on current employment, or similar creditable coverage, you have an 8-month SEP starting when that coverage ends. Enroll within those 8 months to avoid the penalty.

The SEP requires documentation. When you enroll under a Part B SEP, Social Security typically requests Form CMS-L564 ("Request for Employment Information") completed by your former employer, plus Form CMS-40B ("Application for Enrollment in Medicare Part B"). Submit both to your local Social Security office or via mail.

See our Working Past 65 in Ohio hub for the full SEP framework.

Real Ohio examples

How the penalty plays out in practice:

Example 1 — No penalty: Mary turns 65 in March 2024. She enrolls in Part B during her IEP. No penalty. She pays the standard Part B premium plus any IRMAA based on her income.
Example 2 — No penalty (SEP): John retires from Wright-Patterson AFB at 67 in 2025. He had FEHB based on current federal employment. Within 8 months of retiring, he enrolls in Part B using his SEP. No penalty.
Example 3 — 30% penalty: Susan turned 65 in 2021. She delayed Part B without creditable coverage. By the time she enrolled in 2024, she had 36 months of delay — 3 full 12-month periods. Her penalty is 30% (3 × 10%). Her 2026 monthly premium: $202.90 standard + $60.87 penalty = $263.77/month. For life. Over a 20-year retirement, the penalty alone costs her approximately $14,600.
Example 4 — 10% penalty after COBRA: Tom retired at 64 with retiree coverage from his Akron tire-industry employer. He turned 65 in 2023. His retiree coverage continued, but retiree coverage doesn't count as creditable for Part B SEP. By the time he enrolled in Part B in early 2025, he had 22 months of delay — one full 12-month period, plus a partial year. His penalty is 10%. Monthly premium: $202.90 + $20.29 = $223.19/month for life.

Worried about a potential Part B late enrollment penalty in Ohio?A licensed Ohio Medicare agent or OSHIIP counselor can review your specific situation, verify your creditable coverage status, and help you avoid or minimize a penalty. No cost to you.

Find a Medicare Agent in Ohio