Medicare Late Enrollment Penalties (Part B and Part D): How They Work and How to Challenge One

Medicare charges a late enrollment penalty if you didn't sign up for Part B or Part D when you were first able to and didn't have a valid reason, like qualifying employer coverage. The Part B penalty is 10% of the standard premium for each full 12-month period you could have had Part B but didn't. The Part D penalty is 1% of the "national base beneficiary premium" ($38.99 in 2026) for each month you went without creditable drug coverage, and for most people, these penalties last as long as they have that coverage.

How does the Part B late enrollment penalty work?

Medicare.gov says you'll pay an extra 10% for each full 12-month period you could have signed up for Part B but didn't. The penalty is added to your monthly premium.

Medicare.gov's 2026 example: if you waited 2 full years to sign up and didn't qualify for a Special Enrollment Period, you'd pay a 20% penalty on top of the standard Part B premium. The Centers for Medicare & Medicaid Services (CMS) set the standard 2026 Part B premium at $202.90.

For most people, the penalty lasts for as long as you have Part B.

Who can avoid the Part B penalty?

Medicare.gov says you generally won't pay a Part B penalty if:

• You qualify for a Special Enrollment Period. This usually applies if you or your spouse had health coverage through current work when you were first eligible.
• You enroll in a Medicare Savings Program.

If you were working and had employer coverage, keep proof of that coverage. You may need it if Social Security questions your sign-up date.

How does the Part D late enrollment penalty work?

Medicare.gov says you'll pay a penalty if you go 63 days or more in a row without Part D or other creditable drug coverage after your Initial Enrollment Period ends. Creditable coverage is drug coverage expected to pay, on average, at least as much as Medicare's standard drug coverage.

The penalty is figured like this:

1. Count the number of full months you went without creditable coverage.
2. Multiply by 1%.
3. Multiply that by the national base beneficiary premium. Medicare.gov lists it as $38.99 in 2026.
4. Round to the nearest $0.10.

Medicare.gov's 2026 example: if you waited 14 months, you'd pay a 14% penalty. In 2026 that's 14% of $38.99, about $5.46, which rounds to $5.50 a month, added to your plan premium.

Because the base premium changes every year, the dollar amount of your penalty can change each year too. The penalty stays with you even if you switch plans.

Who can avoid the Part D penalty?

Medicare.gov says you generally won't pay it if:

• You had creditable drug coverage, or
• You qualify for Extra Help.

Employers and unions usually send a yearly notice saying whether their drug coverage is creditable. Keep those notices.

How do I challenge a Part D late enrollment penalty?

You can ask for a "reconsideration." Medicare.gov explains:

• Your drug plan will send you information on how to ask.
• You must send your request no later than 60 days from the date on the letter saying you owe a penalty. If it's late, you must explain why.
• Send proof of creditable coverage, like a copy of your old prescription drug card or a creditable coverage notice from an employer or union.
• A Medicare contractor that isn't connected with your drug plan reviews it. In general, Medicare.gov says it decides within 90 days.
• You must keep paying the penalty while you wait.

How do I challenge a Part B penalty?

If you think a Part B penalty is wrong, for example because you had employer coverage, contact Social Security. Have proof of your coverage and dates ready. A State Health Insurance Assistance Program (SHIP) counselor can also help you figure out your options for free.

How do I check my bills for a penalty?

• Part B: Look at your Medicare premium bill or Social Security benefit statement. A penalty shows up as a premium higher than the standard amount.
• Part D: Your plan's premium bill or notice will show the late enrollment penalty as a separate amount.
• Check for Extra Help. If you now qualify, the Part D penalty may go away.

Frequently asked questions

How much is the Part B late penalty?

10% of the standard Part B premium for each full 12-month period you could have had Part B but didn't. It's usually charged for as long as you have Part B.

How much is the Part D late penalty in 2026?

1% of $38.99 for each month without creditable coverage, rounded to the nearest $0.10, added to your premium each month.

Can I get a Part D penalty removed?

You can ask for a reconsideration within 60 days of the penalty letter, with proof of creditable coverage.

Does Extra Help remove the Part D penalty?

Medicare.gov says you generally won't pay a Part D late enrollment penalty if you qualify for Extra Help.

Want to know if you're paying a penalty?

Bill Review Coach is a monthly medical bill review service for seniors and their families. Snap a photo of your premium bill or penalty letter, and we'll explain what you're being charged, whether a deadline applies, and what to say when you call. You make the calls and write the emails; we help you know what to say.