Medicare Part D Late Enrollment Penalty Calculator
Calculate your monthly penalty for enrolling in prescription drug coverage after your deadline
Your Medicare Part D Late Enrollment Penalty
What is Creditable Prescription Drug Coverage?
Creditable coverage is prescription drug coverage that's expected to pay, on average, at least as much as Medicare's standard Part D coverage.
- Employer or union retiree drug plans
- TRICARE (military health coverage)
- Veterans Affairs (VA) drug coverage
- Indian Health Service drug coverage
- Some state pharmaceutical assistance programs
- Medicare Advantage plans with drug coverage
How Part D Penalties Work:
The Part D late enrollment penalty is calculated as 1% of the national base beneficiary premium ($35.63 in 2025) for each month you were eligible but didn't have creditable coverage. This penalty is permanent and added to your monthly premium for as long as you have Part D coverage.
Important Reminders:
Part D penalties are permanent and compound over time. If you're unsure about whether your previous coverage was creditable, contact your former plan administrator or Medicare at 1-800-MEDICARE. This calculator provides estimates—always verify with official Medicare sources.