The Medicare late enrollment penalty is an extra amount added to your monthly premium when you sign up for Medicare Part B and Part D (and sometimes Part A) later than you should have. It is not a one-time fee meaning it could be a lifetime penalty! Here is what each penalty actually costs and how to avoid paying it.
What Is a Medicare Late Enrollment Penalty?
A late enrollment penalty is a permanent addition to your monthly premium that applies if you go without coverage similar to Medicare and then enroll after your Initial Enrollment Period. The amount is based on how long you waited, so a short delay costs less than a long one. You generally avoid the penalty if you had other qualifying coverage (such as an active employer plan) or you qualify for a Special Enrollment Period. Source: Medicare.gov.
How Much Is the Part B Late Enrollment Penalty?
The Part B penalty adds 10% to your premium for each full 12-month period you could have had Part B but didn’t sign up. That extra amount is calculated against the standard Part B premium ($202.90 in 2026) and stays on your bill for as long as you have Part B.
If you delayed two full years, your penalty is 20% on top of the standard premium. If you delayed five years, it is 50%, every month, indefinitely. Source: Medicare.gov.
Note: Higher earners may also pay an income-related amount on top of Part B and Part D. That’s call IRMAA and is different that what we are discussing here.
How Much Is the Part D Late Enrollment Penalty?
The Part D penalty applies if you go 63 days or more without creditable drug coverage after your Initial Enrollment Period. It adds 1% for each month you went without coverage (12% for a full year) to the national base beneficiary premium ($38.99 in 2026). So a 14-month gap means a 14% penalty added to your drug plan premium every month, for as long as you have Part D coverage.
You generally avoid this penalty if you keep creditable drug coverage (coverage at least as good as Part D) or you qualify for Extra Help. Senior65 doesn’t sell Part D, so we recommend enrolling directly at Medicare.gov, but it helps to understand the penalty before you decide to skip drug coverage. Source: Medicare.gov.
How Much Is the Part A Late Enrollment Penalty?
Most people get premium-free Part A and never face this penalty. It only applies if you have to buy Part A (because you or your spouse didn’t pay into Medicare for enough years) and you don’t enroll when first eligible. In that case your premium may go up 10%.
The Part A penalty works differently from the others. Instead of lasting for life, you pay it for twice the number of years you delayed. If you were eligible for two years before signing up, you pay the higher premium for four years. Source: Medicare.gov.
How Late Enrollment Affects Your Medigap Coverage
Medigap (Medicare Supplement) doesn’t have a monitary late enrollment penalty in the way Part B and Part D do. If you are late to enroll in Medigap, however, you could be penalized by not being able to enroll!
Your one-time Medigap Open Enrollment Period is a six-month window that starts when you are 65 or older and enrolled in Part B. During that window you can buy any Medigap plan sold in your state at the best available price, with no health questions asked.
If you are outside this 6 month window and don’t qualify for a Medigap Special Enrollment Period (SEP) typically have to go through medical underwriting before being approved Medsupp plan. This means you could be turned down for Medigap for pre-existing conditions if you enroll late.
The good news is that you don’t have to be in perfect health to qualify for Medigap approval via Medical Underwriting. Many applicants with pre-existing conditions are approved (though approval is never guaranteed). You can check with our Instant Medigap Underwriting Checker. Some states like New York and CT also have year-round enrollment without underwriting.
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How Do You Avoid Medicare Late Enrollment Penalties?
The simplest way to avoid every penalty is to sign up during your Initial Enrollment Period, the seven-month window around your 65th birthday. If you have other qualifying coverage when you turn 65, the rules give you ways to delay without penalty:
- If you have active employer coverage through your own or a spouse’s current job, you usually get a Special Enrollment Period to sign up for Part B without penalty when that coverage ends.
- Keep creditable drug coverage (through an employer plan or similar) to avoid the Part D penalty. Check that your plan counts as creditable before you turn 65.
- COBRA and retiree coverage do not count as active employer coverage for delaying Part B, so don’t rely on them to avoid the Part B penalty.
💡 Tip: If you are turning 65 and unsure whether your current coverage lets you delay safely, confirm with your plan’s administrator before your Initial Enrollment Period ends. Getting the timing right protects both your Part B premium and your no-questions-asked window to buy Medigap. For the bigger picture, see our guide for those new to Medicare.
Talk to Our Team Before You Decide
Late enrollment penalties are easy to trigger by accident and hard to undo, so it pays to get your timing right the first time. If you are weighing when to enroll or which Medigap plan fits, our team at Senior65 can walk you through your options and help you compare prices in your state. Our help is free, and by law no one can offer you a lower price on the same plan. Call 800-930-7956 to speak with our team, or start a quote online whenever you’re ready.