How Does the Medicare Part B Late Enrollment Penalty Work?

If you don’t enroll in Medicare Part B when you’re first eligible and you don’t qualify for an exception, Medicare may add a late enrollment penalty to your Part B premium.

• Your Part B premium generally increases by 10% for each full 12-month period you could have had Part B but didn’t enroll. Medicare.gov — Part B Late Enrollment Penalty
• The penalty generally continues for as long as you have Medicare Part B. Medicare.gov — Avoid Late Enrollment Penalties
• A higher premium because of income is different from a late enrollment penalty. See my web page — Medicare Part B & Part D IRMAA High-Income Surcharge.
• If you have to pay a premium for Medicare Part A, Part A has a different late-enrollment rule. See my web page — Medicare Part A if You Have to Buy It.

Before You Assume You Owe a Part B Penalty

There are important exceptions. Before assuming that you have to pay a lifelong Part B late enrollment penalty, check whether one of these rules applies to you.

• You or your spouse had group health coverage based on current employment: You may qualify for a my web page — Medicare Part B Special Enrollment Period. See also Social Security — Sign Up for Part B Only.
• You have limited income: A my web page — Medicare Savings Program / Medi-Cal May Pay Your Part B Premium may help. Medicare says people who enroll in a Medicare Savings Program generally don’t have to pay a Part B late enrollment penalty. Medicare.gov — Avoid Late Enrollment Penalties.
• You missed enrollment because of an exceptional situation: Medicare now has Special Enrollment Periods for circumstances including loss of Medicaid/Medi-Cal, certain emergencies or disasters, misinformation from an employer or health plan, and release from incarceration. See CMS — Original Medicare Part A & Part B Eligibility and Enrollment.

It can be worth checking the enrollment rules before simply accepting a lifetime penalty.

Part B Late Enrollment Penalty Example

For 2026, the standard Medicare Part B premium is $202.90 per month. Medicare premiums change each year, so for later years see Medicare.gov — Current Medicare Premiums, Deductibles & Costs.

• If you delayed Part B for one full 12-month period, the penalty would generally be 10%.
• If you delayed for two full 12-month periods, the penalty would generally be 20%.
• If you delayed for five full 12-month periods, the penalty would generally be 50%.

Medicare’s 2026 example: A person who waited two full years would have a 20% penalty. Using the 2026 standard premium, Medicare calculates a monthly premium of approximately $243.50, including the penalty.
Medicare.gov — See the Part B Penalty Calculation.

The percentage of your penalty can remain the same, but the dollar amount can change when the standard Part B premium changes.

I Missed Medicare Part B Enrollment — What Can I Do Now?

• First, check for a Special Enrollment Period. See my web page — Medicare Part B Special Enrollment Period.
• If no Special Enrollment Period applies, you may need the General Enrollment Period. See my web page — How to Apply for Medicare Part B During the General Enrollment Period.
• The Medicare Part B General Enrollment Period runs January 1 through March 31. Coverage now starts the month after you enroll. Medicare.gov — When Does Medicare Coverage Start?
• If you already have Medicare Part A and need to add Part B, see Social Security — Sign Up for Part B Only.

Does My Other Health Insurance Protect Me From the Part B Penalty?

• Coverage through your or your spouse’s current employment: This may qualify you to delay Part B and use a Special Enrollment Period later. See my web page — Employer Group Health Coverage vs. Medicare.
• COBRA: COBRA does not extend your 8-month Part B Special Enrollment Period. That clock generally starts when employment ends or the employer group coverage ends, whichever happens first. Medicare.gov — COBRA and Medicare.
• Retiree coverage: Retiree insurance is generally not considered coverage based on current employment for the normal Part B employer SEP. See my web page — Medicare Part B Special Enrollment Period.
• Covered California or other individual insurance: Do not assume an individual policy lets you safely postpone Medicare Part B. Check your Medicare eligibility and enrollment rules before delaying Part B.

If you’re leaving employer coverage, this is a good time to verify your dates before cancelling anything.

FAQ — I Was Incarcerated. Can I Avoid a Part B Penalty?

Possibly, yes. Medicare now has a Special Enrollment Period for certain formerly incarcerated people who did not enroll, lost Medicare because premiums weren’t paid, or voluntarily terminated Medicare while incarcerated.

• The Special Enrollment Period generally begins when you’re released from custody.
• It generally lasts through the 12th month after release.
• If you qualify and enroll using this Special Enrollment Period, Medicare says the Part A and Part B late enrollment penalties do not apply.
• See CMS — Medicare for Incarcerated and Formerly Incarcerated Beneficiaries.

FAQ — What If I Live Outside the United States?

Living outside the United States can make the decision about Medicare Part B much more complicated. Original Medicare generally has very limited coverage outside the United States, but dropping or delaying Part B can affect your future enrollment and late enrollment penalty if you return.

• See my web page — Medicare Outside the United States.
• Medicare has a publication specifically for people living abroad: Medicare — Medicare if You Live Outside the United States, CMS Product #11871.
• Do not assume that simply returning to the United States automatically gives everyone a penalty-free Part B enrollment period. The answer depends on your citizenship, Social Security status, work coverage and enrollment history.

FAQ — What If I’m New to the United States or Don’t Have Enough Medicare Work Credits?

Medicare eligibility can be different for someone who is not eligible for premium-free Part A based on their own or a spouse’s work history.

• If you don’t have enough Medicare work credits, you may have to buy Medicare Part A. See my web page — Medicare Part A if You Have to Buy It.
• Lawful permanent residents who aren’t otherwise entitled to Medicare may be subject to Medicare’s continuous U.S. residency requirements before they can purchase Medicare based on age.
• If your income is limited, before paying hundreds of dollars each month for Part A and Part B, check my web page — Medicare Savings Programs / Medi-Cal Help Paying Medicare Premiums.

FAQ — Can I Cancel Medicare Part B?

Yes, Medicare Part B can generally be voluntarily terminated, but Medicare warns that dropping Part B can create a gap in coverage and a future late enrollment penalty if you don’t qualify for another Special Enrollment Period.

• If you’re considering dropping Part B because you’re returning to work, first review my web page — Employer Group Coverage vs. Medicare.
• If you’re considering dropping Part B because you’re moving abroad, first review my web page — Medicare Outside the United States.
• See Medicare.gov — How to Drop Part A & Part B for the current procedure and warnings.

Don’t cancel Part B until you understand when and how you could get it back.

How Do I Know My Medicare Part B Enrollment Went Through?

• Check your Social Security account for the status of your Medicare application.
• Check your Medicare account after enrollment to confirm your Part A and Part B effective dates.
• See my web page — Set Up Your Social Security & Medicare Online Accounts.

Need help figuring out which Medicare enrollment rule applies?
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Resources

• Medicare.gov — Avoid Late Enrollment Penalties
• Medicare.gov — When Does Medicare Coverage Start?
• Social Security — Sign Up for Medicare Part B Only
• CMS — Original Medicare Part A & Part B Eligibility and Enrollment
• Medicare & You — CMS Product #10050