If you think you missed a Medicare deadline, take a breath: most penalties are avoidable, and many people who worry about one never actually owe it. The Medicare late enrollment penalty is a surcharge added to your premium when you sign up for Part A, Part B, or Part D later than you were supposed to, without other coverage that counts. The amount depends on which part you delayed and for how long. This guide walks through how each penalty is calculated, how long it lasts, and the clear steps you can take to avoid one or keep it from growing. If you are still unsure which deadline applied to you, our guide to Medicare enrollment periods lays out every window.
How the Medicare late enrollment penalty works, part by part
A late penalty is not a one-time fee or a bill for back premiums. For Part B and Part D, it is a permanent surcharge added to your monthly premium for as long as you keep that coverage. Each part calculates it in its own way, so it helps to take them one at a time.
Part B: 10% per year you delayed
If you do not enroll in Part B during your Initial Enrollment Period and you do not qualify for a Special Enrollment Period or a Medicare Savings Program, your monthly Part B premium goes up 10% for each full 12-month period you could have had Part B but did not. The penalty stays with you for as long as you have Part B. Note that those are the Part B exceptions: creditable coverage is a Part D term for prescription drug coverage, and it does not excuse a late Part B enrollment.Centers for Medicare & Medicaid Services. (n.d.). Avoid late enrollment penalties. medicare.gov. Retrieved Jul 15, 2026, from https://www.medicare.gov/basics/costs/medicare-costs/avoid-penalties
It is easier to see with a number. The standard Part B premium is $202.90 a month, the amount CMS (the federal Medicare agency) set for 2026.Centers for Medicare & Medicaid Services. (2026). 2026 Medicare Parts A & B Premiums and Deductibles. cms.gov. Retrieved Aug 7, 2026, from https://www.cms.gov/newsroom/fact-sheets/2026-medicare-parts-b-premiums-deductibles If you went two full years without Part B when you could have had it, that is a 20% surcharge, or about $40.58 added to that base premium, every month, for the rest of the time you have Part B. A single full year would be 10%; three full years, 30%. Partial years do not count, so a gap of 11 months adds nothing, while a gap of 13 months counts as one full 12-month period.Centers for Medicare & Medicaid Services. (n.d.). Avoid late enrollment penalties. medicare.gov. Retrieved Jul 15, 2026, from https://www.medicare.gov/basics/costs/medicare-costs/avoid-penalties
The most common way people avoid this is simple: sign up during your Initial Enrollment Period, the seven-month window around your 65th birthday. The other way is to have coverage from a current employer that lets you delay. If you are still working at 65, read our guide to creditable coverage before you decide to wait on Part B, because not every kind of insurance protects you.
Part D: 1% per month without drug coverage
Part D, the prescription drug benefit, has its own penalty, and it is keyed to months rather than years. For each full month you were eligible for Part D but went without it or without other creditable drug coverage, Medicare adds 1% of the national base beneficiary premium to your Part D premium. Like the Part B penalty, it lasts as long as you have Part D.Centers for Medicare & Medicaid Services. (n.d.). Avoid late enrollment penalties. medicare.gov. Retrieved Jul 15, 2026, from https://www.medicare.gov/basics/costs/medicare-costs/avoid-penalties
Two details matter here. First, the trigger is the 63-day rule: the penalty applies if you go 63 or more continuous days after the end of your Part D Initial Enrollment Period without either Part D coverage or other creditable drug coverage. A short gap will not cost you; a gap that crosses 63 days will.Centers for Medicare & Medicaid Services. (n.d.). Creditable prescription drug coverage. medicare.gov. Retrieved Aug 22, 2026, from https://www.medicare.gov/health-drug-plans/part-d/basics/creditable-coverage Second, the penalty is a percentage, not a fixed dollar amount. The "national base beneficiary premium" it is calculated from is a figure Medicare sets each year, so the exact dollar amount can shift slightly from year to year even though your percentage stays fixed. Your percentage is set by how many full months you went uncovered. For 2026 that base premium is $38.99, so a two-year gap of 24 full months means a 24% penalty, which works out to about $9.40 added to your monthly Part D premium (Medicare rounds the penalty to the nearest 10 cents).Centers for Medicare & Medicaid Services. (n.d.). Creditable prescription drug coverage. medicare.gov. Retrieved Aug 22, 2026, from https://www.medicare.gov/health-drug-plans/part-d/basics/creditable-coverage For more on how this part works, see our Medicare Part D guide.
Part A: only if you have to buy it
Most people never face a Part A penalty, because about 99% of beneficiaries get Part A premium-free, based on at least 40 quarters (10 years) of Medicare-covered work. If you qualify for premium-free Part A, there is no late penalty to worry about, and you can sign up at any time.Centers for Medicare & Medicaid Services. (2026). 2026 Medicare Parts A & B Premiums and Deductibles. cms.gov. Retrieved Aug 7, 2026, from https://www.cms.gov/newsroom/fact-sheets/2026-medicare-parts-b-premiums-deductibles
The penalty applies only to the small share of people who must buy Part A because they do not have enough work history. For them, signing up late means the premium may go up 10%, and unlike the others, you pay it for a set stretch rather than for life: twice the number of years you delayed. Delay two years, and you pay the higher premium for four. Usually no penalty applies if you meet the conditions that let you sign up for Part A during a Special Enrollment Period.Centers for Medicare & Medicaid Services. (n.d.). Avoid late enrollment penalties. medicare.gov. Retrieved Jul 15, 2026, from https://www.medicare.gov/basics/costs/medicare-costs/avoid-penalties
| Part | How it's calculated | How long it lasts | How to avoid it |
|---|---|---|---|
| Part B | 10% added to your premium for each full 12-month period you could have had Part B but did not | As long as you have Part B | Enroll during your Initial Enrollment Period, or qualify for a Special Enrollment Period or a Medicare Savings Program |
| Part D | 1% of the national base beneficiary premium for each full month without Part D or creditable drug coverage | As long as you have Part D | Avoid a gap of 63 or more days; keep creditable drug coverage and your annual notice, or qualify for Extra Help |
| Part A | Premium may go up 10%; applies only if you must buy Part A | For twice the number of years you delayed | Sign up on time, or during a Part A Special Enrollment Period; most people get Part A premium-free and owe no penalty |
How to avoid a Medicare late enrollment penalty
The good news running through all three penalties is that they are avoidable, and the steps are within your control. There are really two paths.
Enroll on time. The cleanest way to never owe a penalty is to sign up during your Initial Enrollment Period, the seven-month window that spans the three months before your 65th birthday, the month itself, and the three months after. If you are not sure your window has passed or is still open, our Medicare enrollment periods guide walks through each one.
Or keep coverage that counts, and keep the proof. If you have other coverage when you turn 65, you may be able to delay penalty-free, but only if that coverage is creditable. For drug coverage, creditable means it is expected to pay, on average, at least as much as Medicare's standard Part D coverage. CMS says creditable coverage includes, but is not limited to, some employer-based prescription drug coverage (including the Federal Employees Health Benefits Program), qualified State Pharmaceutical Assistance Programs, military-related coverage such as TRICARE and VA drug benefits, certain Medigap policies, and Indian Health Service, Tribal, or Urban Indian program coverage. CMS guidance says drug coverage from a current or former employer or union may be considered creditable, so whether yours counts turns on that sponsor's annual determination. Drug discount cards, free clinics, and drug discount websites do not count.Centers for Medicare & Medicaid Services. (n.d.). Creditable prescription drug coverage. medicare.gov. Retrieved Aug 22, 2026, from https://www.medicare.gov/health-drug-plans/part-d/basics/creditable-coverage Each entity that offers drug coverage has to decide every year whether what it offers is creditable and send you a written notice saying so. Because Medicare's fall Open Enrollment starts October 15, that notice has to reach you before then.Centers for Medicare & Medicaid Services. (n.d.). Creditable Coverage — CMS (employers and plan sponsors). cms.gov. Retrieved Jul 30, 2026, from https://www.cms.gov/medicare/prescription-drug-coverage/creditablecoverage
Save those notices. If you later join a Part D plan, it may send you a letter asking about your prior coverage, and you will need to respond by the deadline to prove you had continuous creditable coverage and avoid the penalty. Keeping each year's notice in one place is the single best insurance against a Part D penalty you do not actually owe.
One warning about COBRA (continuation coverage): it is not coverage based on current employment, so it does not let you delay Part B without a penalty. Your Part B Special Enrollment Period runs for up to 8 months from the day your job or your employer group coverage ends, not from the day COBRA ends, so waiting out your COBRA months first can leave you with both a lifetime Part B penalty and a coverage gap.Centers for Medicare & Medicaid Services. (n.d.). COBRA coverage. medicare.gov. Retrieved Jul 17, 2026, from https://www.medicare.gov/basics/get-started-with-medicare/medicare-basics/working-past-65/cobra-coverage If that is your situation, read COBRA instead of Medicare Part B before you decide.
If you already owe a penalty
If a penalty is already on your premium, you still have options, and two are worth knowing.
Ask for a review if you think it is wrong. If a Part D penalty was added but you actually had creditable drug coverage during the months in question, start with the paperwork trail. When you joined your Part D plan, it may have sent you a letter asking whether you had creditable drug coverage; if that form went back after the deadline, or never went back at all, the plan had no way to know you were covered, and the penalty follows automatically.Centers for Medicare & Medicaid Services. (n.d.). Creditable prescription drug coverage. medicare.gov. Retrieved Aug 22, 2026, from https://www.medicare.gov/health-drug-plans/part-d/basics/creditable-coverage Call your plan, ask how the penalty was calculated and how to request a review of it, and send the creditable coverage notices your previous plan gave you as proof. Those same notices are what support a Part B penalty question you raise with Social Security.
Check whether Extra Help exempts you. People who qualify for Extra Help, the federal Part D Low-Income Subsidy that helps pay drug costs, are not charged the Part D late enrollment penalty.U.S. Government Publishing Office. (n.d.). 42 CFR 423.780(e) — Premium subsidy; waiver of late enrollment penalty for subsidy-eligible individuals. ecfr.gov. Retrieved Jul 11, 2026, from https://www.ecfr.gov/current/title-42/section-423.780 CMS guidance applying 42 CFR 423.286(e), 423.773(c) and 423.780(e) goes further than a pause: if you are already paying the penalty when Extra Help starts, the penalty is removed and your count of uncovered months resets to zero, and losing Extra Help later does not bring those months back. What survives is any penalty already billed and unpaid for months before Extra Help began, plus a new gap of 63 or more continuous days without creditable coverage counted from the day after Extra Help ends.U.S. Government Publishing Office. (n.d.). 42 CFR 423.780(e) — Premium subsidy; waiver of late enrollment penalty for subsidy-eligible individuals. ecfr.gov. Retrieved Jul 11, 2026, from https://www.ecfr.gov/current/title-42/section-423.780 If your income and resources are limited, applying for Extra Help through Social Security can both lower your drug costs and clear the Part D penalty you are already paying. Our guide to Extra Help and the Part D late enrollment penalty covers how that works.
To act on any of this, use the operative federal channels directly.
Frequently Asked Questions
How long does the Part B late enrollment penalty last?
For as long as you have Part B, which for most people means for life. The penalty is 10% added to your premium for each full 12-month period you could have had Part B but did not, and it does not go away once you finally enroll. That is why signing up during your Initial Enrollment Period, or keeping coverage that lets you delay, matters so much.
Does having job-based coverage protect me from a penalty?
It can, but only if the coverage counts as creditable. Coverage from a current employer can let you delay Part B penalty-free, and drug coverage that pays on average at least as much as standard Part D lets you delay Part D penalty-free. Not every plan qualifies. COBRA is the trap: it is not coverage based on current employment, so it does not protect you from a Part B penalty, and your Part B Special Enrollment Period starts when the job or the employer coverage ends rather than when COBRA does.Centers for Medicare & Medicaid Services. (n.d.). COBRA coverage. medicare.gov. Retrieved Jul 17, 2026, from https://www.medicare.gov/basics/get-started-with-medicare/medicare-basics/working-past-65/cobra-coverage Confirm your coverage counts before you decide to wait, and see our creditable coverage guide for the details.
How do I prove I had creditable drug coverage?
Each year, before Medicare's October 15 Open Enrollment start, whoever provides your drug coverage has to send you a written notice telling you whether that coverage is creditable.Centers for Medicare & Medicaid Services. (n.d.). Creditable Coverage — CMS (employers and plan sponsors). cms.gov. Retrieved Jul 30, 2026, from https://www.cms.gov/medicare/prescription-drug-coverage/creditablecoverage Save these notices. When you later join a Part D plan, it may send a letter asking about your prior coverage, and you must respond by the deadline with proof of continuous creditable coverage to avoid the penalty. The annual notices are how you show you never crossed the 63-day gap.
Can a Medicare penalty ever be removed?
Sometimes. If you believe a penalty was charged in error, you can ask your plan for a review, and your saved creditable coverage notices are the evidence that supports your case; people who qualify for Extra Help are not charged the Part D penalty at all. The section above, if you already owe a penalty, walks through both paths and who to contact.
Will the General Enrollment Period erase my penalty?
No. Signing up during a later window, like the General Enrollment Period, gets you enrolled, but it does not undo a penalty for the months you went without coverage you could have had. The penalty attaches when you enroll. That is why the goal is to avoid the gap in the first place, not to count on a later window to fix it.
Learn More
If you are weighing whether to delay Medicare or worried you already missed a deadline, get personalized help sorting out your penalty risk and your next step at brevy.com.
The information on Brevy.com is for educational purposes only and is not a substitute for professional legal, financial, or medical advice. Rules vary by state and program and change frequently. Always verify with the relevant agency or a qualified professional. Brevy is not a law firm, financial advisor, or healthcare provider.