Medicare Late Enrollment Penalties Explained

Miss the Part B or Part D deadline without a qualifying exception, and you face a permanent premium surcharge — 10% for Part B, up to 1% per month for Part D.

Part B late enrollment penalty

If you delay Part B past your Initial Enrollment Period (IEP) without qualifying coverage, you pay a permanent 10% surcharge on your monthly premium for as long as you have Part B.

Your IEP runs 3 months before, the month of, and 3 months after your 65th birthday. Enroll then. If you work and have employer coverage, you may qualify for a Special Enrollment Period when you leave that job.

Part D late enrollment penalty

Drop Part D drug coverage without a gap, then re-enroll later? You pay a surcharge equal to 1% of the national average drug plan premium for each full month you were without creditable coverage, for as long as you have Part D.

This penalty compounds annually as the base premium rises. Miss 1 year of coverage, and you're paying roughly 12% extra forever.

Exceptions that avoid penalties

You avoid the Part B penalty if you had other creditable coverage (like an employer plan) when you turned 65, and you enroll within 8 months of that coverage ending.

You avoid the Part D penalty if you had creditable drug coverage from an employer or union, or if you qualify for a Special Enrollment Period due to moving, loss of coverage, or other qualifying life events.

When to enroll

Enroll in Part B during your IEP (3 months before your 65th birthday through 3 months after). Enroll in Part D during your IEP or when your employer coverage ends.

If you miss these windows, immediately contact Social Security or Medicare to apply. Penalties accrue, so every month of delay makes the long-term penalty worse.

Frequently asked questions

What's the Part B late enrollment penalty if I delay 2 years?

You pay a 10% surcharge for the rest of your life — it doesn't compound yearly, just stay 10% above the standard premium forever.

Can the penalty be waived?

Rarely. Only if CMS determines you made a reasonable effort but couldn't enroll, or if you were misinformed. Most delays don't qualify for waiver.

What if I had employer coverage when I turned 65?

You likely have a Special Enrollment Period. Enroll in Part B and D within 8 months of that coverage ending to avoid penalties.

Does the Part D penalty ever go away?

No. It stays for the lifetime of your Part D coverage, compounding annually as premiums rise.

General educational information only, not legal or tax advice. Medicare penalties, exceptions, and Special Enrollment Periods are complex. Confirm your eligibility and timeline with Social Security or Medicare.

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