Patient Responsibility

Medicare Late Enrollment Penalty: How to Appeal It

Name: Medicare Late Enrollment Penalty: How to Appeal It
Creator: Barley Billing Team
Published: 2026-09-24

Written by Barley Billing Team, Medicare Billing Experts | Fact-checked against primary CMS sources | Last reviewed September 24, 2026

Were you charged a Medicare Part B or Part D late enrollment penalty?

"Medicare says I owe a late enrollment penalty"

"My Part B premium went up because I signed up late"

"My drug plan says I have a Part D late enrollment penalty"

"I want to appeal my Medicare late enrollment penalty"

Let's check whether you have a valid ground to challenge the penalty, and which reconsideration route applies — Social Security for Part B, the independent reviewer for Part D.

What This Means

Your Social Security notice, Medicare premium bill, or Part D plan letter says you owe a late enrollment penalty — an ongoing add-on to your monthly premium because of a period without Medicare or equivalent coverage. Part B and Part D each have their own penalty, their own rules for what counts as protected coverage, and their own way to challenge the amount. Part B penalties are challenged through Social Security; Part D penalties through the independent reviewer named on your drug plan’s notice, not the plan itself.

Part B penalty. If you did not sign up for Part B when you were first eligible, and did not qualify for a Special Enrollment Period, your premium goes up 10% for each full 12-month period you could have had Part B but didn’t (Medicare.gov: Avoid late enrollment penalties). On the standard 2026 Part B premium of $202.90, two full years uncovered means a 20% penalty — $40.58 more a month (20% of $202.90), for a total of $243.48, which Medicare rounds to $243.50. You generally pay this penalty for as long as you have Part B.

Part D penalty. If you went 63 days or more without Part D drug coverage or other creditable drug coverage after your initial enrollment period ended, your drug plan adds 1% of that year’s national base beneficiary premium for every full uncovered month, rounded to the nearest 10 cents (Medicare.gov: Avoid late enrollment penalties; 42 CFR 423.46(a)). The national base beneficiary premium is $38.99 for 2026 and $41.33 for 2027, and Medicare recalculates the dollar penalty from that year’s premium each year, so the amount you owe can change from one year to the next even though the percentage locked in at the time does not.

Both penalties can be wrong or unfairly applied. If you had coverage that should have protected you, or were misinformed by the government or an employer, you may be able to get the penalty reduced or removed.

Why This Happens

Group health coverage was never checked against the right rule. Only coverage based on current employment — yours or a working spouse’s — protects you from the Part B penalty. Retiree coverage, COBRA, and VA benefits do not, however good they are, and it is a common and expensive misunderstanding.
Creditable drug coverage was never reported. Part D plans learn about your prior drug coverage from what you tell them at enrollment and from employer or union reporting. If that information didn’t reach the plan, it will assume the gap was uncovered.
A Special Enrollment Period was missed or never claimed. Both programs have SEPs for people affected by a government error, an employer or health plan’s wrong information, or an emergency or disaster. For Part B, months covered by one of these can be excluded from the penalty calculation, but only if you enrolled within that SEP.
Extra Help wasn’t on file for the period in question. People who qualify for the Part D Low-Income Subsidy (Extra Help) don’t pay a Part D penalty while they have it, no matter when the coverage gap happened, but the plan needs a record of that eligibility to apply it.
Social Security’s records were incomplete or wrong. Part B reconsideration exists in part because these determinations are made from records that can be incomplete or wrong. Part D works differently: the independent reviewer only considers the specific grounds listed on the reconsideration form, so an unraised, undocumented claim of a “miscount” isn’t itself something the reviewer will act on.

Should You Appeal?

Appeal outlook: Mixed — it depends on why the coverage gap happened

Part B — request reconsideration through Social Security, not Medicare. The Part B late enrollment penalty is a Social Security determination — the premium adjustment under 42 CFR 408.22 is an initial determination (42 CFR 405.924(a)(5)) — appealed the same way any Social Security decision is: request reconsideration, generally within 60 days of receiving the decision, using Form SSA-561-U2 or Social Security’s online process (SSA: Request reconsideration). Social Security presumes you received the decision 5 days after the date on it, unless you can show otherwise (POMS GN 03101.010). If you’ve missed the deadline, file anyway and explain why you were late — Social Security can accept a late request for good cause (20 CFR 404.911). Strong grounds include:

You had group health coverage based on current employment — yours or a spouse’s — during the months counted against you (42 CFR 408.24(a)(7)(i) excludes those months from the penalty; if you’re under 65 and have Medicare because of a disability, the same exclusion is 42 CFR 408.24(a)(9); 42 CFR 407.20 is the related special enrollment period).
Equitable relief — a federal employee or someone authorized to act for the government gave you wrong information, or made an error, that caused the late enrollment (42 CFR 407.32).
An employer or health plan misinformed you, for enrollments on or after January 1, 2023: months covered by this exceptional-conditions Special Enrollment Period do not count against the penalty, but only if you enrolled within that SEP, which runs 6 months from the day you told Social Security about the misinformation (42 CFR 408.24(b)(2), 42 CFR 407.23(c)(2)).
You had Medicare because of a disability before 65 and have now turned 65. Once you’re 65, months before the month you turned 65 aren’t counted toward your Part B penalty; if your premium still reflects them, ask Social Security to recompute it (42 CFR 408.24(a)(5)). If you’re still under 65, this ground doesn’t apply yet.
You qualify for a Medicare Savings Program. If your state pays your Part B premium through a Medicare Savings Program, you generally won’t have to pay the Part B penalty (42 CFR 408.24(a)(3)) — apply through your state Medicaid office.
The months were simply miscounted.

Part D — request reconsideration by an independent reviewer, not your plan. Your Part D plan sends an LEP Reconsideration Notice and request form with the penalty notice. The review itself is not done by your plan — it’s conducted by CMS or an Independent Review Entity (IRE) under contract with Medicare, and by law the review is done by CMS or its contractor, not the plan (42 CFR 423.46(c)). You must submit the reconsideration form within 60 days from the date on the letter telling you that you owe the penalty; a late request must include an explanation of the delay, though the reviewer can still dismiss a late request (Medicare.gov: Avoid late enrollment penalties; Part D LEP Reconsideration Request Form). Note that you generally won’t get another chance to ask for reconsideration of the Part D penalty if you joined a different drug plan earlier and were already paying a penalty (Medicare.gov: Avoid late enrollment penalties). The reviewer only considers the grounds listed on the reconsideration form:

You had creditable prescription drug coverage — employer, union, TRICARE, VA, or another source that paid, on average, at least as much as standard Part D coverage — during the months counted against you.
You had drug coverage but didn’t get a notice that clearly explained whether it was creditable (42 CFR 423.56(g)).
You weren’t eligible to enroll in Part D during that period — for example, you were living outside the United States.
You were unable to enroll because of a serious medical emergency.
You have or had Extra Help. While you have Extra Help you don’t pay the Part D penalty, whenever the gap happened; give the form your Extra Help dates (42 CFR 423.780(e)).

A Part D reconsideration decision is generally final — there’s no further appeal level, though CMS may review and revise it at its discretion (42 CFR 423.46(c)), so send all your evidence the first time. By law, you must keep paying the penalty while a reconsideration is pending, even if you disagree with it or have already requested a review.

What To Do Next

Read your notice closely. It tells you which penalty you’re being charged (Part B or Part D), the months counted as uncovered, and — for Part D — the exact deadline and instructions for requesting reconsideration.
Gather your evidence first. For Part B: proof of group health coverage based on current employment, documentation of misinformation or an SEP you qualified for, proof of your disability-based entitlement if you turned 65, or proof of Medicare Savings Program enrollment. For Part D: proof matching your ground — creditable drug coverage for the disputed months, proof you weren’t eligible to enroll, proof of a serious medical emergency, or proof of Extra Help eligibility.
Part B: request reconsideration from Social Security. File within 60 days of receiving the decision (presumed 5 days after the date on it), using Form SSA-561-U2, online, or by calling 1-800-772-1213 and telling the representative you want to request reconsideration of a Part B late enrollment penalty determination. If you’re past 60 days, ask anyway and explain the delay — good cause can excuse a late filing (SSA: Request reconsideration; POMS GN 03101.010).
Part D: complete the LEP Reconsideration Request Form and send it to the Independent Review Entity, following the address or fax number on the form — not your drug plan. You must do this within 60 days from the date on the letter telling you that you owe the penalty; a late request must include an explanation of the delay, though the reviewer can still dismiss a late request (Medicare.gov: Avoid late enrollment penalties; Part D LEP Reconsideration Request Form). In general, the IRE decides within 90 calendar days of receiving your request (CMS: Late Enrollment Penalty (LEP) Appeals), sometimes 14 days longer for good cause (Medicare.gov: Avoid late enrollment penalties).
Keep paying the billed premium while your case is pending. A successful reconsideration corrects your premium going forward and may include a refund; it does not pause what you owe in the meantime.
If you need help, contact your State Health Insurance Assistance Program (SHIP). A SHIP counselor can review your notice, help gather documentation, and walk through either reconsideration process for free — find yours at shiphelp.org or by calling 1-800-MEDICARE (1-800-633-4227).

Sources

Medicare.gov: Avoid late enrollment penalties — the Part B 10%-per-year formula and 2026 example calculation ($202.90 standard premium, $40.58/20% penalty, $243.48 rounded to $243.50), the Part D 1%-per-month formula, the 63-day gap threshold, the 2026 national base beneficiary premium ($38.99), and the Part D reconsideration process (a Medicare contractor not connected with the drug plan does the review, 60-day filing window from the notice date, explanation required for a late filing, no second reconsideration chance if you already joined a different plan while paying a penalty, and a 90-day decision with a possible 14-day extension).
CMS: 2026 Medicare Parts A & B Premiums and Deductibles — the $202.90 standard 2026 Part B premium.
CMS: Medicare Part D 2027 National Average Monthly Bid Amount Information — the $41.33 2027 national base beneficiary premium.
CMS: Late Enrollment Penalty (LEP) Appeals — the Part D reconsideration process, confirming review is conducted by CMS or an Independent Review Entity rather than the plan, and the 90-day decision timeframe.
Part D LEP Reconsideration Request Form (C2C) — the five grounds the IRE will review, the 60-day filing window from the notice date, and the instruction to explain a late filing.
42 CFR 408.22 — Increased premiums for late enrollment — the 10%-per-full-12-months Part B penalty formula.
42 CFR 407.20 — Special enrollment period related to coverage under group health plans — the special enrollment period for current-employment group health coverage.
42 CFR 407.32 — Prejudice to enrollment rights because of Federal Government misrepresentation, inaction, or error — the equitable relief ground for Part B.
42 CFR 408.24 — Individuals who enrolled or reenrolled before April 1, 1981 or after September 30, 1981 — paragraph (a)(3) excludes months under a state Medicaid buy-in agreement; paragraph (a)(5) excludes, for someone now 65 or older, months before they turned 65; paragraph (a)(7)(i) excludes months after December 1982 when someone age 65 or over was covered under a group health plan by reason of current employment; paragraph (b)(2) excludes months covered by an exceptional-conditions SEP from the Part B penalty period for enrollments on or after January 1, 2023, provided the person enrolled within the SEP.
42 CFR 405.924 — Actions that are initial determinations — paragraph (a)(5): a Part B premium adjustment under 42 CFR 408.22 is an initial determination, which is why it’s appealed as a Social Security reconsideration.
42 CFR 407.23 — Special enrollment periods for exceptional conditions — paragraph (c)(2) is the SEP for individuals misinformed by an employer or health plan, running 6 months from the day the person notifies Social Security of the misrepresentation.
42 CFR 423.46 — Late enrollment penalty — the Part D penalty trigger (63+ days without creditable coverage) and paragraph (c), which places the reconsideration with CMS or an Independent Review Entity and states the decision is not subject to appeal but may be reviewed and revised at CMS’s discretion.
42 CFR 423.56 — Verification of creditable coverage — paragraph (g), the ground for challenging a Part D penalty when you didn’t get a notice clearly explaining whether your coverage was creditable.
42 CFR 423.780 — Premium subsidy — paragraph (e), Extra Help (LIS) recipients are not subject to the Part D late enrollment penalty.
20 CFR 404.911 — Good cause for missing the deadline to request review — the good-cause standard for a late Social Security reconsideration request.
Social Security POMS GN 03101.010 — Time Limit for Filing Administrative Appeals — the 60-day appeal period and the presumption that notice is received 5 days after the date on it.

Not sure if your bill is right? Check it against Medicare's rules →

Frequently Asked Questions

How is the Part B late enrollment penalty calculated?

Add 10% of the standard Part B premium for every full 12-month period you were eligible for Part B but did not have it, and were not covered by a Special Enrollment Period. For 2026 the standard premium is $202.90, so two full years uncovered adds 20%, or $40.58 more a month (20% of $202.90), for a total of $243.48, which Medicare rounds to $243.50. You generally pay this penalty for as long as you have Part B.

How is the Part D late enrollment penalty calculated?

Multiply 1% of that year's national base beneficiary premium by the number of full months you went without Part D or other creditable drug coverage after your initial enrollment period ended, then round to the nearest 10 cents. The national base beneficiary premium is $38.99 for 2026 and $41.33 for 2027, and Medicare recalculates the penalty using the current year's premium each year, so the dollar amount changes even though the percentage does not.

What's the deadline to challenge each penalty?

For Part B, Social Security's late enrollment penalty determination is an initial determination (42 CFR 405.924(a)(5)), and Social Security's general reconsideration deadline is 60 days from when you receive the decision. Social Security presumes you received the decision 5 days after the date printed on it, unless you can show otherwise. For Part D, medicare.gov and the reconsideration form both describe a 60-day window from the date on the letter telling you that you owe the penalty. Follow the date and instructions printed on your own notice. If you've missed either deadline, file anyway and explain why you were late: Social Security can accept a late Part B request for good cause, and a late Part D request must include an explanation of the delay, though the reviewer can still dismiss a late request.

What evidence do I need?

For Part B, bring proof of group health coverage based on current employment (yours or a spouse's), such as an employer benefits letter or plan enrollment records, or documentation of the misinformation or error that caused the late enrollment. For Part D, bring proof matching your ground: creditable prescription drug coverage for the months in question, such as a notice of creditable coverage from an employer, union, TRICARE, or VA plan; proof you weren't eligible to enroll during that period, such as proof of living outside the United States; proof of a serious medical emergency that kept you from enrolling; or proof of your Extra Help dates.

Does Extra Help remove the Part D penalty?

Yes. If you qualify for the Part D Low-Income Subsidy, known as Extra Help, you don't pay a Part D late enrollment penalty while you have it, no matter when the coverage gap happened. If a penalty is still showing on your premium after you were approved for Extra Help, that is a strong reason to request reconsideration.

See If Your Bill Is Right

Barley checks your bill or Medicare notice against Medicare's rules — so you know if there's an error and what to do about it.

Check My Bill

Free to start. No credit card.

Already a member? Open your dashboard →

This information is for educational purposes only and is not legal or medical advice. Always verify with your doctor's office and insurance company.