By the Kryder Cares Data Desk · Reviewed by Kris Kryder, licensed agent · Updated
Key points
- Penalties are added to your monthly premium — they’re not a one-time fee.
- Part B: 10% for each full 12-month period without Part B, for as long as you have Part B.
- Part D: 1% of the national base premium ($38.99 in 2026; $41.33 in 2027) per uncovered month.
- Job-based coverage from current work, creditable drug coverage, Extra Help and Medicare Savings Programs can protect you.
Why Medicare has penalties at all
Medicare encourages people to sign up when they’re first eligible, during the 7-month Initial Enrollment Period around 65, unless they have other coverage that’s similar in value. If you wait without that coverage, a late enrollment penalty is added to your monthly premium. CMS is clear on three points: penalties aren’t a one-time late fee, they grow the longer you wait, and for Part B and Part D they usually last as long as you have that coverage.
The window details are in our enrollment periods guide. Here’s how each penalty works.
The Part B penalty
If you don’t sign up for Part B when you’re first eligible and don’t qualify for a Special Enrollment Period, your Part B premium goes up 10% for each full 12-month period you could have had Part B but didn’t. You generally pay it for as long as you have Part B. And because you can only sign up during the General Enrollment Period (January 1 – March 31) after missing your window, you may also go months without coverage.
CMS gives its own 2026 example: someone who waited 2 full years would pay a 20% penalty in addition to the $202.90 standard premium, for a monthly Part B premium of $243.50 in 2026. The penalty is figured on the standard premium for each year, so the dollar amount changes when the premium does. Estimate yours with our Part B penalty calculator.
You generally won’t owe a Part B penalty if you qualify for a Special Enrollment Period — for example, the 8-month window after job-based coverage from current work ends — or if you enroll in a Medicare Savings Program.
The Part D penalty
If, after your Initial Enrollment Period ends, you go 63 days or more in a row without Part D or other creditable drug coverage (coverage similar in value to Part D), you may owe a penalty when you join a drug plan. It equals 1% of the national base beneficiary premium for each full month you went without, rounded to the nearest $0.10, and it’s added to your premium for as long as you have Medicare drug coverage — even if you switch plans.
The base premium is $38.99 for 2026 and $41.33 for 2027, so the penalty is recalculated each year. CMS’s 2026 example: waiting 14 months without creditable coverage means a 14% penalty, or $5.50 a month in 2026. Try our Part D penalty calculator.
Your drug plan tells you if a penalty applies. If you disagree — for instance, if you had creditable coverage the plan didn’t know about — you can ask for a review. Keep the yearly creditable-coverage notices your employer or union plan sends.
The Part A penalty (for people who buy Part A)
Most people don’t pay a Part A premium, so they never face this one. If you have to buy Part A because you don’t have enough work history and don’t buy it when first eligible, your premium may go up 10%, and you pay the higher premium for twice the number of years you didn’t sign up. CMS’s example: eligible for 2 years without signing up means 4 years of the higher premium. A Special Enrollment Period usually avoids it.
What isn’t a penalty, but feels like one
Medigap has no late enrollment penalty, but missing your 6-month Medigap Open Enrollment Period can mean medical questions, higher prices or being turned down later. See Medicare Advantage vs. Medigap.
COBRA and retiree coverage are traps for many people. Neither counts as coverage from current employment for Part B, so they don’t protect you from the Part B penalty. COBRA with creditable drug coverage can protect you from the Part D penalty, though.
Coverage that lets you delay safely
- Group health coverage from your or your spouse’s current job, generally with an employer of 20 or more employees — see working past 65.
- Creditable prescription drug coverage (for Part D), from an employer, union, TRICARE or the VA.
- Extra Help: you won’t pay a Part D penalty while you have it.
- A Medicare Savings Program: generally waives the Part B penalty.
How Kris helps
Kris reviews your current coverage before your 65th birthday or retirement date and tells you plainly whether it protects you from penalties. If you’ve already been charged one, she can explain the letter and your options. Read her article on avoiding late penalties, or book a no-cost meeting.
Your next step
Have questions about your own situation? Contact Kris or schedule a no-cost meeting. You can also read more about Medicare Part D and Medicare Supplement (Medigap).
Sources
- CMS — Avoid late enrollment penalties
- CMS — Costs for Medicare drug coverage
- CMS — Medicare Part D 2027 national average monthly bid amount
- CMS — Working past 65
- CMS — When can I sign up for Medicare?
- CMS — Help with drug costs (Extra Help)
- CMS — Get ready to buy a Medigap policy
We do not offer every plan available in your area. Currently we represent 14 organizations which offer 119 products in your area. Please contact Medicare.gov or 1-800-MEDICARE to get information on all of your options. This is a proprietary website and is not associated, endorsed or authorized by the Social Security Administration, the Department of Health and Human Services or the Center for Medicare and Medicaid Services. This site contains decision-support content and information about Medicare, services related to Medicare and services for people with Medicare. If you would like to find more information about the Medicare program please visit the Official U.S. Government Site for People with Medicare located at www.medicare.gov.
This guide is general education, not a recommendation for any specific plan or policy. Figures were current as of October 19, 2026; plan details and government amounts change every year.