The Part B late enrollment penalty lasts for as long as you have Part B. Remember to check whether you’re eligible for a special enrollment period, as these periods may help you avoid late enrollment penalties.
Most people become eligible for Medicare when they turn age 65, but if you don’t enroll when you’re first eligible, you may have to pay a late enrollment penalty.
Different penalties apply to the different Medicare parts, and while some only last for a specific period, the Part B penalty applies for the entire time your plan is active.
You can enroll in Medicare during your 7-month initial enrollment period (IEP), which begins 3 months before your 65th birth month, continues throughout your birth month, and ends 3 months later.
Medicare usually charges a late enrollment penalty if you do not enroll during your IEP. You must pay this additional amount in addition to the usual monthly premium.
Late enrollment penalties are not one-time late fees, and they may:
- last for as long as you have the plan
- be added to your monthly premium payments
- increase the longer you wait to enroll
In 2025, the standard Part B premium is $185 per month. If Medicare applies a Part B late enrollment penalty, this amount will increase by 10% for each year you could have enrolled but chose not to.
Example of the Part B late enrollment penalty calculation
- Standard Part B premium in 2025 = $185
- You did not enroll for 2 years = 10% x 2 years = 20%
- $185 + 20% = $222
Your new premium will be $222 for the entire time you have an active Part B plan.
IRMAA calculations
If you earn more than a specific amount, your monthly Part B premiums will be higher than the standard $185. This amount is called an income-related monthly adjustment amount (IRMAA).
The following table shows the IRMAA brackets for 2025 and the amount that will be added to the standard Part B premium. These costs are based on your 2023 annual tax returns.
| If you file taxes as an individual | If you file taxes jointly | Amount added to the standard Part B monthly premium |
|---|---|---|
| $106,000 or less | $212,000 or less | + $0 |
| more than $106,000 and up to $133,000 | more than $212,000 and less than or equal to $266,000 | + $74.00 |
| more than $133,000 and up to $167,000 | more than $266,000 and less than or equal to $334,000 | + $185.00 |
| more than $167,000 and up to $200,000 | more than $334,000 and less than or equal to $400,000 | + $295.90 |
| more than $200,000 and less than $500,000 | more than $400,000 and less than $750,000 | + $406.90 |
| $500,000 or above | $750,000 or above | + $443.90 |
If you’re married but filing taxes separately, your 2025 IRMAA surcharges are:
| If you are married but file separate taxes | Amount added to the standard Part B monthly premium |
|---|---|
| more than $106,000 but less than $394,00 | + $406.90 |
| $394,000 or more | + $443.90 |
If you have alternative healthcare coverage of similar value to Medicare, such as through an employer or a spouse’s employer, you may be eligible for a special enrollment period (SEP).
Being eligible for a SEP means you will not usually have to pay a late enrollment penalty.
Other reasons you may qualify for an SEP include not enrolling due to:
- a natural disaster
- misleading or false information from a healthcare plan or employer
- incarceration
- volunteering and serving in a foreign country
If you have questions about whether you qualify for an SEP, you can contact Medicare 24/7 at 800-633-4227 (TTY: 877-486-2048) or by using its helpful online chat tool.
Medicare considers “creditable coverage” as a suitable alternative, meaning health insurance expected to pay at least as much as Medicare’s standard coverage. Examples include employer or union group health plans, certain retiree coverage, TRICARE, VA benefits, or other coverage Medicare designates as creditable.
If you do not enroll in Medicare when you are first eligible, you may have to pay a late enrollment penalty, particularly if you do not have other health insurance equivalent to a Medicare plan.
Once Medicare has added the Part B late enrollment penalty to your monthly premium, it will remain in place as long as your Part B plan remains active.
If you do not enroll in Medicare Part B when you are first eligible, but have alternative equivalent healthcare coverage, you may qualify for a special enrollment period (SEP), which often means you will avoid late enrollment penalties.