Medicare Part D Penalty Calculator
Find out how much you may owe in late enrollment penalties — and what it will cost you each month for the rest of your Medicare coverage.
Calculate Your Penalty
Enter the number of full months you went without Medicare Part D or other creditable drug coverage after your Initial Enrollment Period ended.
* Estimate uses the 2025 national base beneficiary premium of $36.78/month. This tool is for educational purposes only and may not reflect your exact penalty. Consult Medicare or a licensed broker to confirm.
What Is the Part D Late Enrollment Penalty?
If you don't sign up for Medicare Part D (prescription drug coverage) when you're first eligible, and you go 63 or more days in a row without creditable drug coverage, Medicare adds a permanent late enrollment penalty to your monthly Part D premium.
The penalty is calculated as 1% of the national base beneficiary premium multiplied by the number of full months you went without Part D or other creditable drug coverage.
The Formula
The result is rounded to the nearest $0.10 and added to your monthly premium. CMS updates the base premium each year, so your penalty amount can shift slightly.
Example
How to Avoid the Penalty
- ✓Enroll in Part D during your Initial Enrollment Period (3 months before to 3 months after your 65th birthday month)
- ✓Keep creditable drug coverage through an employer, union, VA, TRICARE, or FEHB plan
- ✓Enroll in a Medicare Advantage plan that includes drug coverage (MAPD)
- ✓If you lose creditable coverage, enroll in Part D within 63 days
Common Part D Penalty Questions
What counts as 'creditable' drug coverage?
Coverage is creditable if it's expected to pay at least as much as Medicare's standard Part D plan. This includes most employer/union plans, TRICARE, VA coverage, FEHB, and Indian Health Service coverage. Your plan must send you a notice each year confirming whether it's creditable.
When does the penalty start?
The penalty clock starts the month after your Initial Enrollment Period ends if you don't have creditable coverage. It continues until you enroll in a Part D plan.
Is the penalty permanent?
Yes — you pay the penalty for as long as you have Medicare drug coverage. It does not go away after a certain number of years.
Does the penalty amount change each year?
Yes. Because the penalty is tied to the national base beneficiary premium (which CMS sets annually), your penalty dollar amount can change slightly each year even though your number of uncovered months stays fixed.
Can I appeal or have the penalty waived?
In limited cases — for example, if you can prove you had creditable coverage that wasn't correctly reported. You can request a reconsideration through Medicare. Ashley can walk you through whether an appeal makes sense in your situation.