Medicare late enrollment penalty calculator
Sign up late for Part B and the premium goes up 10% for each full year you waited. Go without drug coverage and Part D costs 1% more for each month. Both usually last as long as you have the coverage.
Only full 12-month periods count.
Your Part B premium each month, 2026
$243.50
- Standard Part B premium
- $202.90
- Part B penalty (20%)
- $40.58
- Part D penalty (14%), added to your plan premium
- $5.50 a month
- Both penalties over 12 months
- $553.20
Medicare rounds each amount to the nearest 10 cents. Figures are for 2026.
The Part B penalty
You pay an extra 10% for each year you could have signed up for Part B but did not. Medicare's own example: wait 2 full years (24 months) without qualifying for a Special Enrollment Period, and you pay a 20% penalty on top of the standard premium. For 2026 that is $202.90 plus $40.58, which comes to $243.50 a month after rounding.
Generally there is no Part B penalty if you qualify for a Special Enrollment Period, or if you enroll in a Medicare Savings Program.
The Part D penalty
You pay an extra 1% for each month, which is 12% a year, if you do not join a Medicare drug plan when you first get Medicare, or if you go 63 days or more without creditable drug coverage. The percentage is applied to the national base beneficiary premium, which is $38.99 in 2026 and $41.33 in 2027.
Medicare's example: 14 months late is a 14% penalty. In 2026 that is 14% of $38.99, or $5.46, rounded to $5.50 a month and added to your plan's premium. Because the base premium changes each year, so does the penalty.
Generally there is no Part D penalty if you have creditable drug coverage or you qualify for Extra Help.
The Part A penalty
Most people pay no premium for Part A, so this one is rare. If you have to buy Part A and do not buy it when you are first eligible, your monthly premium may go up 10%. You pay the higher premium for twice the number of years you did not sign up: 2 years late means 4 years of the higher premium.
How long the penalties last
The Part B and Part D penalties are usually charged for as long as you have that coverage. For most people that means for life. The Part A penalty is the exception.
Questions people ask
How much is the Part B late enrollment penalty?
An extra 10% of the standard premium for each full year you could have signed up but did not. Two years late in 2026 means $243.50 a month, not $202.90.
How is the Part D late enrollment penalty calculated?
1% of the national base beneficiary premium for each month without creditable drug coverage. The base premium is $38.99 in 2026, so 14 months late adds $5.50 a month.
Do Medicare late penalties ever go away?
The Part B and Part D penalties are usually charged for as long as you have that coverage. The Part A penalty lasts twice the number of years you did not sign up.
Check our work
Every figure on this page was read from these official documents. Follow the links and compare.
- Avoid late enrollment penaltiesMedicare.gov. Read on November 12, 2026.
- CostsMedicare.gov. Read on November 12, 2026.
- Medicare Part D 2027 National Average Monthly Bid Amount InformationCenters for Medicare & Medicaid Services. Read on November 12, 2026.