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What Will Delaying Part B Cost You?

Delay Part B without the right kind of coverage and Medicare adds 10% to your premium for every full year you waited — permanently. Enter three things to see what you'd owe, and the month to enroll by to stop it growing. Free for everyone — no membership required.

Medicare Part B Penalty Calculator

About 1 min
Takes about a minute

Three questions, one number.

The penalty depends on when your Initial Enrollment Period ended (set by your birthday), when you sign up for Part B, and how many of the months in between you had coverage from a current employer.

Your date of birth
When do (or did) you sign up for Part B?The month you enroll — or plan to. Coverage normally begins the following month; the penalty counts every uncovered month through the month you sign up.

An estimate under Medicare's standard rules; Social Security makes the final determination when you enroll. Special Enrollment Periods and equitable relief can reduce or erase a penalty.

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Social Security makes the final call when you enroll — and a Special Enrollment Period or equitable relief can change it. A licensed AMAC advisor checks your situation, files the paperwork, and compares plans for your doctors and prescriptions, at no cost.

  • We check whether a Special Enrollment Period applies
  • We handle the Part B application and CMS-L564
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  • Same price as going direct — we never mark it up
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Where are you with Part B?

No cost. No obligation. A plan costs the same through AMAC as buying it direct.

Good to Know

The Part B Penalty, Explained

What is the Medicare Part B late-enrollment penalty?
A permanent surcharge on your Part B premium for signing up late. For each full 12-month period you could have had Part B but didn't, 10% of the standard premium ($202.90 in 2026) is added to what you pay every month — and because it's a percentage of the standard premium, it rises whenever the premium does.
How are the uncovered months counted?
From the month after your Initial Enrollment Period ends (the seven months around the month you turn 65) through the month before your Part B coverage begins. Only full 12-month periods count: 11 uncovered months means no penalty, 12 means 10%, 24 means 20%, and so on. Months when you or your spouse had coverage from a current employer's plan — while one of you was still working, whatever the employer's size — are subtracted. (Enrollments before 2023 were counted slightly differently, through the close of the enrollment period; this calculator covers 2023 onward.)
Does the penalty ever go away?
For Part B, no — it lasts as long as you have Part B. (The Part A penalty, for people who have to pay a Part A premium, lasts twice the number of years you delayed.) The ways to avoid it after the fact are to show you qualified for a Special Enrollment Period, or to be granted equitable relief because Social Security or Medicare itself gave you wrong information (an employer's mistake doesn't qualify, though newer exceptional-circumstances Special Enrollment Periods sometimes do).
What counts as coverage that stops the penalty?
A group health plan from a current employer — yours or your spouse's — while one of you is still working. The employer's size doesn't matter for the penalty (it only decides whether the plan or Medicare pays first). COBRA, retiree health plans, Marketplace (ACA) plans, VA coverage and individual policies do not count, even though you were insured. Many people are surprised by this; an advisor can confirm which category your coverage falls in.
I'm still working at 65. Should I delay Part B?
Usually yes, if your employer has 20 or more employees: you avoid the Part B premium while the employer plan pays first, and you get an 8-month Special Enrollment Period with no penalty when that coverage ends. If the employer has fewer than 20 employees, Medicare pays first and you should generally enroll at 65. Either way, take premium-free Part A unless you contribute to a Health Savings Account.
Is there a penalty for Part D too?
Yes, and it's calculated differently: 1% of the national base beneficiary premium ($38.99 in 2026) for every month without creditable drug coverage after your Initial Enrollment Period, rounded to the nearest 10¢ and added to your Part D premium for as long as you have drug coverage. It only applies once you've gone 63 days or more without creditable drug coverage, and its Special Enrollment Period after employer coverage ends is only two months.

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