Medicare Late Enrollment Penalty: How to Avoid It and Appeal

Why Medicare Has Late Enrollment Penalties

Medicare uses late enrollment penalties to keep the system financially stable. If people could sign up only when they got sick, premiums would skyrocket for everyone. The penalties are designed to reward people who enroll on time and to spread costs fairly across the entire Medicare pool.

There are three separate penalties, one for each part of Medicare that can carry a premium: Part A (hospital), Part B (medical), and Part D (prescription drugs). Each is calculated differently, and each lasts a different length of time. The Part B and Part D penalties, in particular, are generally permanent, which is why understanding the rules before you delay is so important.

If this is your first time navigating Medicare, our step-by-step enrollment guide walks through the timing rules that keep you penalty-free.

The Medicare Part B Late Enrollment Penalty

Part B is where most people get hit with a penalty because it carries a monthly premium ($202.90 for the standard 2026 rate) and the surcharge is permanent. For context, the 2026 Part B deductible is $283, so a penalty stacks on top of an already-rising base cost.

How the Part B penalty is calculated

The Part B late enrollment penalty is 10% of the standard Part B premium for each full 12-month period you could have had Part B but did not enroll, and that extra amount is added to your monthly Part B premium for as long as you have Part B. Only full 12-month periods count, so an 11-month delay produces no penalty, while a 13-month delay counts as one full year.

The formula is straightforward:

Monthly penalty = 10% × $202.90 × (number of full years delayed)

That works out to about $20.29 per month for every full year of delay, which Medicare then adds to your standard premium and rounds to the nearest 10 cents.

2026 Part B penalty examples

If you waited 2 full years (24 months) to sign up for Part B and did not qualify for a Special Enrollment Period, you will pay a 20% late enrollment penalty (10% for each full 12-month period). Over a typical 20-year retirement, that adds up to nearly $10,000 in extra premiums for just a two-year delay.

The Medicare Part D Late Enrollment Penalty

Part D covers prescription drugs, and its penalty structure is different but just as permanent.

How the Part D penalty is calculated

The Part D penalty is 1% of the national base beneficiary premium for every full month you went without Part D or other creditable prescription drug coverage after you were first eligible.

For 2026, the national base beneficiary premium is $38.99, a 6% increase from $36.78 in 2025. That means:

Monthly penalty = 1% × $38.99 × (number of full uncovered months)

So one uncovered month adds about $0.39 per month to your Part D premium, and 12 uncovered months add about $4.68 per month, permanently. Medicare rounds the final figure to the nearest 10 cents. Medicare's own 2026 example: if you waited 14 months after you were eligible for Medicare to join a Medicare drug plan, and you did not have creditable drug coverage, you will have to pay a 14% penalty, which works out to about $5.50 per month for the rest of your life.

2026 Part D penalty examples

Here is how longer delays look at the 2026 base premium of $38.99:

The 63-day rule matters here. If you go 63 or more days in a row without Part D or creditable drug coverage after your Initial Enrollment Period, the penalty clock starts. For details on how drug coverage pairs with a supplement, see our Medigap and Part D guide.

The Medicare Part A Late Enrollment Penalty

Part A is unique because most people never pay a premium for it, and therefore never face a penalty. But if you or your spouse worked fewer than 40 quarters (10 years) of Medicare-taxed employment, you have to buy Part A, and a penalty can apply.

2026 Part A premiums and penalty rules

For 2026, people who must buy Part A pay either $311 per month (30-39 work quarters) or $565 per month (fewer than 30 quarters). The late enrollment penalty adds an extra 10% to that premium.

The Part A penalty has one big advantage over Part B and Part D: it is not permanent. You pay the higher premium for twice the number of years you delayed. So a 2-year delay means 4 years of the 10% surcharge, and then it goes away.

Our Medicare Parts A, B, C, D beginner's guide explains which part of Medicare covers what, so you know exactly what you are enrolling in.

How to Avoid the Late Enrollment Penalty

There are three main ways to avoid a Medicare late enrollment penalty: enroll on time, keep creditable coverage, or qualify for a Special Enrollment Period.

1. Enroll during your Initial Enrollment Period

Your Initial Enrollment Period is the 7-month window that starts three months before the month you turn 65 and ends three months after. Signing up during this window means no penalty, ever, on any part of Medicare.

2. Keep creditable coverage

Creditable coverage is health or drug coverage that is at least as good as Medicare's standard benefit. If you have creditable coverage, you can delay Medicare without penalty. Common creditable coverage sources include:

• For Part B: Group health coverage based on current active employment (your own or a spouse's). Note that COBRA and retiree coverage generally do not count. Our guide on working past 65 explains this in detail.
• For Part D: Employer or union prescription drug plans, VA benefits, TRICARE, FEHB, and some Medigap policies sold before 2006.

Get written proof of creditable coverage from your plan every year. You will need it if Medicare ever questions your enrollment history.

3. Use a Special Enrollment Period (SEP)

An SEP lets you enroll outside the normal windows without penalty when certain life events happen. Details on each type are in our Special Enrollment Periods guide, but the main categories are:

• Loss of employer coverage: 8-month SEP for Part B, 63-day window for Part D
• Moving out of your plan's service area
• Losing Medicaid or Extra Help
• Natural disasters or declared emergencies in your area (SEP begins on the first day of the declaration and runs for 6 months after it ends)
• Release from incarceration (12-month SEP after release)
• Volunteering abroad for a recognized 501(c)(3) organization
• Employer, plan, or federal agency misinformation that caused you to miss enrollment
• New for 2026: A temporary SEP for Medicare Advantage enrollees who relied on incorrect provider directory information in Medicare Plan Finder, if they discovered the issue within three months of the plan's effective date

Exceptions and Waivers

Certain groups are protected from late enrollment penalties entirely:

If you qualify for Extra Help (the Low Income Subsidy), you generally do not pay a Part D late enrollment penalty at all, even if you enrolled late.

How to Appeal or Request Reconsideration

If you receive a late enrollment penalty notice you believe is wrong, you have the right to appeal. The process differs by part.

Appealing a Part D penalty

Part D penalty appeals go to C2C Innovative Solutions, the Independent Review Entity contracted by Medicare to handle Part D LEP reconsiderations. You have 60 days from the date of the penalty notice to file.

Step-by-step process:

1. Get the form. Request the "Part D LEP Reconsideration Request Form C2C" from your Part D plan or download it from CMS.gov.
2. Fill it out. Include your Medicare number (MBI), plan name, penalty amount, and a clear explanation of why the penalty is wrong. A signature by the enrollee is required on this form in order to process an appeal.
3. Attach evidence. Letters from prior employers, unions, or insurers confirming dates and creditability of your previous drug coverage are the most powerful proof.
4. Submit to C2C. By USPS mail: C2C Innovative Solutions, Inc., Part D LEP Reconsiderations, P.O. Box 44165, Jacksonville, FL 32231-4165. By fax: (833) 946-1912. Submit one reconsideration request per enrollee and include all case documentation in a single submission.
5. Wait for the decision. C2C typically issues a written decision within 90 days.

The reconsideration decision is generally final, but you can request a reopening within 180 days if you obtain new evidence.

Appealing a Part B penalty

Part B penalty appeals go through the Social Security Administration using form SSA-561-U2 (Request for Reconsideration). You have 60 days from your notice to file. Successful appeals usually require proof of federal employee error, misinformation, or a qualifying SEP that was not properly applied. For a broader overview of how Medicare appeals work at every level, see our guide on how to appeal a Medicare denial.

Decision Checklist for Delaying Medicare

Before you decide to delay Part B or Part D enrollment past age 65, walk through this checklist:

• Do I have coverage from current active employment (mine or my spouse's)? Retiree and COBRA do not count for Part B.
• Is my employer plan creditable for Part D? I have written confirmation.
• Have I calculated the lifetime cost of a potential penalty if my delay turns out to not qualify?
• Do I know the exact date my current coverage ends so I can time my Medicare enrollment within the 8-month SEP?
• Am I keeping copies of all creditable coverage notices in a safe place?
• Have I confirmed my employer size? If fewer than 20 employees, Medicare is usually primary and delaying Part B can leave gaps. For a deeper look at how Medicare coordinates with other insurance, this matters.
• Do I qualify for Extra Help, Medicaid, or a Medicare Savings Program? If so, penalty risk drops significantly.

If you check every box confidently, delaying may make sense. If any box is uncertain, enroll on time. The cost of guessing wrong is a lifetime penalty. If you also have a health savings account, see our guide on Medicare and HSA rules before deciding.

Frequently Asked Questions

How much is the Medicare late enrollment penalty in 2026?

The Part B penalty is 10% of the standard $202.90 monthly premium for each full year of delay, or about $20.29 per month per year. The Part D penalty is 1% of the $38.99 national base beneficiary premium per uncovered month, or about $0.39 per month, per uncovered month. The Part A penalty is a flat 10% added to the $311 or $565 monthly Part A premium.

Does the Medicare penalty last forever?

Yes, for Part B and Part D. Both penalties are added to your monthly premium for as long as you keep the coverage, which for most people means the rest of their life. The Part A penalty is the exception. It lasts only twice the length of your delay and then ends.

Can I get the Medicare late enrollment penalty waived?

In rare cases, yes. Waivers are typically granted when a federal employee, government agency, or health plan gave you incorrect information that caused the delay. You can also avoid the penalty entirely if you had creditable coverage, qualified for a Special Enrollment Period, or receive Extra Help or Medicaid benefits.

How do I appeal a Medicare Part D late enrollment penalty?

You appeal by filing the "Part D LEP Reconsideration Request Form C2C" with C2C Innovative Solutions within 60 days of your penalty notice. Include supporting documents such as letters from prior employers or insurers proving you had creditable prescription drug coverage. C2C typically issues a decision within 90 days, and the decision is generally final unless you request a reopening within 180 days.

Does COBRA count as creditable coverage for Medicare Part B?

No. COBRA and retiree coverage do not protect you from the Part B late enrollment penalty. Only group health coverage based on current active employment (yours or your spouse's) counts. If you are on COBRA when you turn 65, you should enroll in Part B during your Initial Enrollment Period to avoid a permanent penalty.