Part D Penalty Calculator
Medicare Part D Late Enrollment Penalty Calculator
Updated for 2025
This calculator estimates your permanent monthly penalty if you enroll in Medicare Part D late (without creditable prescription drug coverage).
How the penalty is calculated (2025 rules):
Penalty = (Number of uncovered months) × 1% × National Base Beneficiary Premium ($36.78 in 2025)
The penalty is rounded to the nearest 10 cents and added to your Part D premium for life.
Source: CMS 2025 Medicare Part D Parameters