What Is The Part D Late Enrollment Penalty?
It’s an amount added to your Medicare drug coverage premium if, after your Initial Enrollment Period ended, you went 63 days or more in a row without Medicare drug coverage or other creditable drug coverage. It applies whether you join a Medicare drug plan or a Medicare Advantage plan with drug coverage.
How Medicare Calculates It
Medicare counts the full months you went without coverage, then multiplies that number by 1% of the national base beneficiary premium. The result is rounded to the nearest 10 cents and added to your monthly premium.
In 2026, the national base beneficiary premium is $38.99, so each full month without coverage adds about $0.39 a month. In 2027, it will be $41.33.
An Example
Say your Initial Enrollment Period ended on April 30, 2024, and your drug coverage starts on January 1, 2026. From May 2024 through December 2025, that’s 20 full months without coverage. In 2026, your penalty would be 20% of $38.99, which rounds to $7.80 a month.
When You Won’t Pay A Penalty
- You join Medicare drug coverage during your Initial Enrollment Period.
- Your time without drug coverage is shorter than 63 days in a row.
- You had creditable drug coverage, such as from a job, union, TRICARE, VA, or a federal employee plan, and your Medicare drug coverage starts within 63 days after it ends.
- You get Extra Help, including through Medicaid or a Medicare Savings Program.
How Long You Pay It
Usually for as long as you have Medicare drug coverage, even if you change plans and even if your plan’s premium is $0. The amount is updated every January, when Medicare sets the new base premium. If you have Medicare because of a disability, any penalty ends when you turn 65.
If You Think Your Penalty Is Wrong
You can ask Medicare to review it. Your drug plan’s penalty letter explains how, and you have 60 days from the date on the letter to ask. You keep paying the penalty during the review. Proof of creditable coverage, like a Notice of Creditable Coverage from a past plan, can help.
Where This Information Comes From
This calculator follows Medicare’s rules as explained on Medicare.gov and in the guidance Medicare gives drug plans.