You are not required to enroll in a Medicare Part D prescription drug plan. However, without Part D or other creditable prescription drug coverage, you’ll be responsible for the full cost of most prescription medications.

Additionally, delaying enrollment may result in a late enrollment penalty if you choose to sign up later.

The late enrollment penalty applies if there’s a period of 63 or more consecutive days after your Initial Enrollment Period during which you lack creditable prescription drug coverage. This penalty is calculated by multiplying 1% of the national base beneficiary premium ($36.68 in 2026) by the number of full, uncovered months you were without coverage. The result is rounded to the nearest $0.10 and added to your monthly Part D premium.

It’s important to note that the national base beneficiary premium may change each year, so your penalty amount can also fluctuate annually.

To avoid this penalty, consider enrolling in a Part D plan when you first become eligible for Medicare or ensure you have other creditable prescription drug coverage