Does the Medicare late enrollment penalty ever go away?

The Part B and Part D penalties last for as long as you have that coverage, which for most people means for life. The Part A penalty is the exception: it applies only to people who must buy Part A, and it is paid for twice the number of years of delay and then stops.

Why does my Part D penalty change from one year to the next?

The Part D penalty is one percent of the national base beneficiary premium for each uncovered month, not one percent of what your own drug plan charges. CMS republishes that national base figure every year, so the dollar cost of an unchanged penalty moves with it even though the percentage stays the same.

I had coverage through my employer after 65. Do I still owe a penalty?

Usually not. Coverage from your own or a spouse's current employment generally opens a Special Enrollment Period with no penalty. Two things that do not count and catch people out: COBRA and retiree coverage. Social Security decides whether a period counted, so this estimator asks you for the uncovered months rather than guessing them.

Is a Part D penalty worth avoiding if I take no medicines at all?

The penalty is charged on the months you went without creditable drug coverage, whether or not you needed any drugs during them. That is the arithmetic, not a recommendation: the trade between a modest drug-plan premium now and a permanent surcharge later is yours to weigh, and a SHIP counselor will talk it through free of charge.

Medicare Late Enrollment Penalty Calculator

Sign up for Medicare Part B or Part D late and the surcharge is permanent. Enter how many months you went without each kind of coverage to estimate what the penalty adds every month, every year, and over a horizon you choose. Part B counts full twelve-month periods only, so partial years cost nothing.

Works offline — your inputs never leave this device. How that works

Part B counts full years only

Ten percent is added for each full twelve-month period you could have had Part B and did not. Partial years are ignored altogether, so being 23 months late costs exactly what being 12 months late costs. Part D is the opposite: it counts every single month.

Months without Part B after you could have had itmonthsLeave out months covered by your own or a spouse's current employer group health plan. COBRA and retiree coverage do not count for this.Months without creditable drug coveragemonthsCoverage is creditable when it is expected to pay at least as much as standard Medicare drug coverage. Your plan tells you so in writing each autumn.Show the running total overyearsYour choice, not ours. We are not going to assert how long you will live in order to make a total look larger.

Added to your premium every month$49.98

Part B penalty (20%)$40.58/mo

Part D penalty (24%)$9.40/mo

Over a year$600

Over 15 years(at this year's figures)$8,996

How the Part B figure was reached

2 full 12-month periods late, at 10% each, is 20% added to the standard premium.

How the Part D figure was reached

24 months without creditable drug coverage, at 1% each, is 24% of the national base premium of $38.99, rounded to the nearest $0.10. This figure changes each year as the national base changes.

These two do not end

The Part B and Part D penalties are charged for as long as you hold that coverage. The percentage is fixed by statute, but the dollars follow each year's premium figures, so the same penalty costs a little more every year. The Part A penalty is the one exception — it applies only to people who must buy Part A, and it stops after twice the years of delay.

Before you assume you owe this

Coverage from your own or a spouse's current employment usually opens a Special Enrollment Period with no penalty at all. Social Security decides whether a period counted, which is why this tool asks you for the uncovered months rather than working them out for you. Work out your own enrollment dates to see which window you are actually in.

Where to take a plan question

We take no money from any insurer and name none, so we are not the place to settle what you buy. These three are, and all of them are free.

Verified 2026-08-02 against Medicare.gov, "Avoid late enrollment penalties"; formulas cross-checked against MLN Matters MM14279, "Medicare Deductible, Coinsurance & Premium Rates: CY 2026 Update" (December 5, 2025) (effective 2026-01-01)

Verified 2026-08-02 against CMS fact sheet, "2026 Medicare Parts A & B Premiums and Deductibles" (released November 14, 2025); figures identical to the statutory notice CMS-8091-N, 90 FR 52063 (November 19, 2025) (effective 2026-01-01)

Verified 2026-08-02 against CMS, "Annual Release of Part D National Average Monthly Bid Amount and Other Part C & D Bid Information" (July 28, 2025) for the national base beneficiary premium; CMS, "Final CY 2026 Part D Redesign Program Instructions" (https://www.cms.gov/files/document/final-cy-2026-part-d-redesign-program-instruction.pdf) for the defined-standard deductible and the annual out-of-pocket threshold (effective 2026-01-01)

Estimate only — not financial, tax, legal, or insurance advice. Only MEDICARE can determine your actual amounts.

Official source: Medicare.gov — Avoid late enrollment penalties ↗

🎓 Understand this tool

What it is

An estimate of the permanent surcharge added to a Medicare premium when someone enrolls later than they could have, worked separately for Part B and for Part D because the two use completely different formulas that people routinely conflate.

How it works

Part B adds 10% for each FULL twelve-month period you could have had it and did not, applied to the current standard premium — partial years are ignored, so 23 months late costs exactly what 12 months late costs. Part D adds 1% of the national base beneficiary premium for each uncovered month, rounded to the nearest ten cents, and that national base is republished annually. Both percentages are statutory; only the dollars move.

Getting the most from it

Count the months between when you could first have enrolled and when you actually did, for each part separately. The two counts are usually different.
Leave out any months covered by your own or a spouse's current employer group health plan. COBRA and retiree coverage do not count for this purpose, which is the trap that catches most people.
For Part D, count months without creditable drug coverage. A plan is creditable when it is expected to pay at least as much as standard Medicare drug coverage, and your plan tells you so in writing.
Set the horizon to something realistic for you. We ask rather than assuming, because asserting a life expectancy in order to make a total look larger is not a thing we are willing to do.

Reading your result

The monthly figure is what is added to your premium, and for Part B and Part D it does not stop. The percentage is fixed by statute, but the dollars follow the current year's premium figures, so the same penalty costs a little more each year. Read the total over your chosen horizon as an estimate of scale rather than a bill.

What it can't tell you

It cannot decide whether your months were genuinely uncovered. Whether a Special Enrollment Period applied, whether your old drug coverage was creditable, and whether an exception fits your circumstances are all determinations Social Security makes on the record. It also does not model the Part A penalty, which applies only to the minority who must buy Part A.

Frequently asked questions

Ten percent is added for each full twelve-month period you could have had Part B and did not sign up, applied to the standard premium for the current year. Partial years are ignored entirely, so being twenty-three months late costs the same as being twelve months late. The estimate here shows both the percentage and the dollars.

Part of: Medicare Enrollment Dates, Penalties, and the Two Coverage Shapes →

Related calculators

Enrollment Dates

Your seven-month Medicare sign-up window is worked out from your birthday, and being born on the first of a month shifts the whole thing a month earlier. Enter your date of birth to estimate your own dates, see when coverage would start, and download them to your calendar. No email address required.

Part B Premium

The standard Medicare Part B premium and annual deductible for 2026, taken straight from the CMS notice that set them, with every year back to 2016 so you can see how fast this line item has actually risen. Higher earners pay more through IRMAA; this page shows the base figure everyone starts from.

Total Cost Estimator

Nobody publishes one number for what a year of Medicare costs a household, because the pieces live in separate documents. This estimator adds them: the Part B premium, any IRMAA surcharge, deductibles, and the drug or supplement premium you supply. Original Medicare and Advantage are shown as two shapes of cost, without a verdict.

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