Updated July 2026 · Reviewed by the CoverageCo team
The Part D late enrollment penalty applies if you go 63 or more days in a row without creditable prescription drug coverage after your Initial Enrollment Period ends. It's calculated per uncovered month, added to your Part D premium, and it lasts for as long as you have Part D coverage — it doesn't expire.
Key takeaways
- The trigger is 63+ continuous days without creditable drug coverage.
- It's permanent. It follows you for as long as you hold Part D.
- Creditable coverage means coverage at least as good as standard Part D — get it in writing.
- People who take no prescriptions are the most likely to get caught by it.
How the penalty is calculated
The penalty is based on the number of full months you went without creditable drug coverage after becoming eligible. It's expressed as a percentage of the national base beneficiary premium — a figure CMS sets each year — and added to whatever your chosen Part D plan charges.
Because the base figure adjusts annually, your penalty amount can change slightly from year to year even though the underlying calculation stays the same.
The important part is not the arithmetic. It's that the penalty attaches for as long as you have Part D coverage. There is no point at which it's considered paid off.
What counts as creditable coverage
Creditable coverage means prescription drug coverage expected to pay, on average, at least as much as standard Medicare Part D. Plans that qualify must tell you so in writing, usually in a notice each fall.
Coverage that commonly qualifies includes drug coverage through a current employer or union plan, and some retiree, VA, or TRICARE coverage.
Keep those notices. If a penalty is ever assessed and you believe it shouldn't have been, that documentation is what resolves it.
Why healthy people get caught
This is the pattern worth naming, because it's so consistent.
Someone turns 65, takes no medications, and reasonably concludes a drug plan is money wasted. Several years pass. Then a diagnosis arrives, prescriptions start, and they enroll in Part D — at which point they learn the penalty applies to every month they skipped, permanently.
A low-cost Part D plan during those healthy years is, in effect, insurance against that outcome. It's one of the few places in Medicare where buying coverage you don't currently need is straightforwardly the right call.
If you think a penalty is wrong
You can ask for a review. If you had creditable coverage during the months in question, or there were extenuating circumstances, the penalty can be reconsidered.
You'll need documentation — those creditable coverage notices are exactly what's required. There are deadlines for requesting a review, so act promptly rather than waiting.
Common questions
How long does the Part D penalty last?
For as long as you have Part D coverage. It's added to your monthly premium permanently rather than being a one-time charge.
What counts as creditable prescription drug coverage?
Coverage expected to pay, on average, at least as much as standard Medicare Part D. Employer and union drug coverage often qualifies, as do some retiree, VA, and TRICARE plans. Qualifying plans must notify you in writing.
I take no medications — do I still need Part D?
Enrolling is usually the safer choice. Skipping it means the penalty accrues for every uncovered month, and it applies permanently once you eventually enroll. A low-cost plan during healthy years avoids that.
Can the Part D penalty be removed?
It can be reconsidered if you had creditable coverage during the months in question or there were extenuating circumstances. You'll need documentation, and there are deadlines for requesting a review.