Short answer
The Part D late enrollment penalty is an extra amount added to your monthly Medicare drug-plan premium if you go 63 continuous days or more after becoming eligible without Part D or other creditable prescription drug coverage. In 2026, Medicare calculates it as 1% of $38.99 for each full uncovered month, then rounds to the nearest 10 cents.
How does the 63-day rule work?
You may owe the penalty if you do not join Part D when first eligible and then go 63 days or more in a row without Part D or other creditable prescription drug coverage. Creditable coverage is expected to pay, on average, at least as much as standard Medicare drug coverage. A plan from an employer, union, VA, TRICARE, or another source may be creditable, but you should ask the plan for written confirmation.
Discount cards, manufacturer coupons, free clinics, and drug discount websites are not creditable drug coverage. For the basics, visit our Medicare Part D guide and how Medicare Part D works.
Discount cards, manufacturer coupons, free clinics, and drug discount websites are not creditable drug coverage. For the basics, visit our Medicare Part D guide and how Medicare Part D works.
What does the 2026 calculation look like?
Medicare uses the national base beneficiary premium, not your individual plan's premium. For 2026, the base amount is $38.99. If you had 14 full uncovered months, Medicare would calculate 14% of $38.99, or $5.46, then round the result to $5.50. That $5.50 is added to the plan premium for 2026.
The number can change from year to year because the national base beneficiary premium can change. The penalty generally continues for as long as you have Medicare drug coverage. Our Part D out-of-pocket cap guide explains a separate 2026 Part D cost rule.
The number can change from year to year because the national base beneficiary premium can change. The penalty generally continues for as long as you have Medicare drug coverage. Our Part D out-of-pocket cap guide explains a separate 2026 Part D cost rule.
Can I avoid or challenge the penalty?
You can usually avoid the penalty by enrolling when first eligible or maintaining continuous creditable drug coverage. Keep every creditable-coverage notice, because a new drug plan can ask for proof of your prior coverage. People who qualify for Extra Help generally do not pay the Part D late enrollment penalty.
If you think a plan assessed the penalty incorrectly, the plan should send a reconsideration notice and request form. You can request a review and provide proof of creditable coverage. See our help paying for Medicare guide for Extra Help information and our Medicare and COBRA FAQ if an employment transition is involved.
If you think a plan assessed the penalty incorrectly, the plan should send a reconsideration notice and request form. You can request a review and provide proof of creditable coverage. See our help paying for Medicare guide for Extra Help information and our Medicare and COBRA FAQ if an employment transition is involved.
Need help with your situation?
Talk through your Medicare options with a licensed specialist.
A short conversation can help you understand the enrollment dates, coverage choices, and plan rules that apply to you. There is no cost for the review.