What Is the Medicare Part D Penalty?

It’s important to sign up for a Medicare Part D prescription drug plan when you enroll in Original Medicare or Medicare Advantage. If you wait too long and sign up later, you’ll face a late enrollment penalty that permanently increases your Part D premiums.

The penalty also applies if you drop your Medicare Part D plan and go without prescription drug coverage for too long.

Here’s what you need to know about the Medicare Part D late enrollment penalty and how to avoid it.

You’ll start to owe a late enrollment penalty if you go at least 63 days without sufficient prescription drug coverage after the end of your initial Medicare enrollment period (when you’re first eligible for Medicare).

The initial enrollment period lasts for seven months around your 65th birthday: the three months before your birthday month, your birthday month and the three months after.

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Your best bet to avoid the penalty is to sign up for Medicare Part D or a Medicare Advantage plan with prescription drug coverage during your initial enrollment period and stay enrolled consistently afterward.

Your Medicare Part D late enrollment penalty gets higher the longer you go without Medicare Part D or other creditable prescription drug coverage.

The penalty is calculated in part based on the national base beneficiary premium for Medicare Part D: $32.74 per month in 2023 ($34.70 in 2024).

The Medicare Part D late enrollment penalty is 1% of that national base beneficiary premium for each full month that you didn’t have Medicare Part D or other creditable prescription drug coverage, rounded to the nearest 10 cents.

If you weren’t covered for two years, for example, that’s 24 months. So you would owe 24% of $32.74, or $7.90 (rounded to the nearest 10 cents), each month for 2023, in addition to your premiums for either your Medicare Part D plan or Medicare Advantage plan with prescription drug coverage.

It’s permanent. You’ll continue to owe the penalty with your premiums if you have Medicare Part D or a Medicare Advantage plan with prescription drug coverage.

Because the penalty is tied to the national base beneficiary premium, it can change yearly. So even if you don’t go without Part D coverage again after you incur the penalty, your penalty amount could go up as the national base beneficiary premium rises.

If you wait to sign up for Medicare Part D because you already have equivalent or better prescription drug insurance, such as coverage from an employer or a union, you won’t owe the Part D late enrollment penalty.

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For that other insurance to count, your non-Medicare prescription drug coverage has to qualify as “creditable prescription drug coverage” because it pays for at least as much as Medicare’s standard prescription drug coverage, on average.

You don’t need to do the math to determine whether your non-Medicare prescription drug coverage qualifies. Plans must tell you every year whether or not your coverage counts as creditable prescription drug coverage.