Medicare late enrollment penalties: how they work and how to avoid them

Written by the My Plan Compass team. Last reviewed October 29, 2026, against Medicare.gov.

Medicare adds a penalty to your premium if you sign up for Part B or drug coverage late without other coverage that counts. The Part B penalty is 10% for each full year you waited. The drug coverage penalty is 1% of a national base premium for each month you went without. Both usually last as long as you have that coverage.

Source: Medicare.gov: Avoid late enrollment penalties. Dollar examples use 2026 amounts, which change every year.

The three penalties

Part B (medical insurance)

The penalty: An extra 10% on your Part B premium for each full year you could have had Part B and did not sign up.
How long: Generally for as long as you have Part B, which for most people is for life.
Example: Waiting 24 months means a 20% penalty. On the 2026 premium of $202.90, you would pay about $243.50 a month.

Part D (drug coverage)

The penalty: An extra 1% of the national base premium for each month you went without drug coverage after you were first eligible, once the gap reaches 63 days in a row.
How long: For as long as you have Medicare drug coverage, even if you switch plans. This includes a Medicare Advantage plan with drug coverage.
Example: Going 14 months without coverage means 14% of the 2026 base premium of $38.99, about $5.50 a month added to your plan premium.

Part A (hospital insurance)

The penalty: Most people get Part A without a premium and never face this. If you have to buy Part A and sign up late, your premium may go up 10%.
How long: Twice the number of years you did not sign up. Two years late means four years of the higher premium.

How to avoid them

Still working? If you or your spouse have health coverage from a current job, you can usually wait. You then have 8 months after the job ends to sign up for Part B without a penalty. COBRA does not extend those 8 months (Medicare.gov: When can I sign up?).
Drug coverage that counts. No Part D penalty if your other drug coverage is at least as good as Medicare's, called creditable coverage. An employer or union plan with drug coverage sends a notice each year saying whether yours counts.
Extra Help. People who get Extra Help with drug costs do not pay the Part D penalty.
Do not drop drug coverage to save a premium. A gap of 63 days or more starts the penalty clock.

After you join a drug plan, the plan tells you if you owe a penalty. If you think it is wrong, the letter explains how to ask for a review.

How My Plan Compass handles this

We ask whether you have other drug coverage, such as from the VA, TRICARE or an employer. Unless you say yes, we leave out Medicare Advantage plans without drug coverage, because going without can mean this penalty later. Our cost estimates do not include a penalty you may already owe, because that depends on your own history.

This guide is general information, not advice about your situation. We are not connected with or endorsed by the U.S. government or the federal Medicare program.