Quick answer: the Part B penalty adds 10% of the standard premium for each full 12-month period you could have had Part B but did not, and it usually lasts as long as you have Part B. The Part D penalty adds 1% of the national base beneficiary premium ($38.99 in 2026, $41.33 in 2027) for each month you went without Part D or other creditable drug coverage, and it lasts as long as you have drug coverage. People who have to buy Part A can owe a 10% penalty for twice the number of years they delayed. Job-based coverage from current work, creditable drug coverage, Extra Help and Medicare Savings Programs can protect you.
Medicare penalties are not one-time late fees. Medicare.gov describes them as amounts added to your monthly premium that, for most people, last a lifetime. A delay of a year or two at 65 can mean paying more every month for decades.
The good news is that penalties are avoidable once you understand the rules, and some can be appealed when they are charged in error. This guide explains how each penalty is calculated with current figures, who is protected, and what to do if you receive a penalty notice. For the bigger picture of when and how to enroll, see our Medicare guide.
Figures and rules below come from Medicare.gov’s Avoid late enrollment penalties page, the Social Security Administration (SSA) and CMS, checked October 2026. Your own situation may qualify for an exception, so confirm with Social Security, your drug plan or your State Health Insurance Assistance Program (SHIP). This is general information, not legal or insurance advice.
How Late Enrollment Penalties Work in General
According to Medicare.gov’s page on avoiding late enrollment penalties, penalties share four traits:
- They are added to your monthly premium.
- They are not a one-time late fee.
- They are usually charged for as long as you have that type of coverage; the Part A penalty is the exception.
- They grow the longer you wait, because they are based on how long you went without coverage similar to Medicare.
The basic way to avoid them is to sign up during your Initial Enrollment Period, the seven months around your 65th birthday, unless you have other coverage that Medicare treats as comparable. Our guide on when to sign up for Medicare explains the window and coverage start dates in detail.
The Part B Late Enrollment Penalty
Part B covers doctor visits, outpatient care and preventive services. Most people pay the standard premium, which CMS lists at $202.90 a month in 2026.
How it is calculated
Medicare.gov says you pay an extra 10% for each full 12-month period you could have signed up for Part B but did not. The penalty is a percentage of the standard premium for the current year, so the dollar amount changes every year as the premium changes.
Medicare.gov’s 2026 example
If you waited 24 months to sign up and did not qualify for a Special Enrollment Period, your penalty is 20%:
| Item | Amount |
|---|---|
| 2026 standard Part B premium | $202.90 |
| 20% late enrollment penalty | $40.58 |
| Total | $243.48, rounded to $243.50 |
Medicare.gov notes that the monthly amount is rounded to the nearest 10 cents. Higher-income people also pay an income-related surcharge, explained in our guide to Medicare premiums and IRMAA, on top of any penalty.
Full periods only
Only full 12-month periods count. Someone who was 11 months late generally owes no Part B penalty, though they may still face a gap in coverage while waiting for an enrollment period. Someone 35 months late owes 20%, not 30%.
How long it lasts
For most people, the Part B penalty lasts as long as they have Part B. One exception: people under 65 who have Medicare because of a disability and paid a Part B penalty generally stop paying it once they turn 65 and qualify for a new Initial Enrollment Period.
The coverage gap problem
The penalty is only half the cost of missing Part B. If you miss your Initial Enrollment Period and do not qualify for a Special Enrollment Period, you generally must wait for the General Enrollment Period from January 1 to March 31. Coverage then starts the month after you sign up, which can leave months without outpatient coverage.
The Part D Late Enrollment Penalty
Part D covers prescription drugs through private plans approved by Medicare. Its penalty works differently.
When you owe it
Medicare.gov says you may owe a Part D penalty if, after your Initial Enrollment Period ends, you go 63 days or more in a row without Part D or other creditable prescription drug coverage. Creditable coverage is drug coverage expected to pay, on average, at least as much as standard Medicare drug coverage.
How it is calculated
The penalty is 1% of the national base beneficiary premium for each full month you went without coverage. Medicare.gov lists the base premium as $38.99 in 2026. CMS announced on July 28, 2026 that it will be $41.33 in 2027.
Medicare.gov’s 2026 example
If you joined a drug plan 14 months after your eligibility and had no creditable coverage during that time:
| Item | Amount |
|---|---|
| 2026 national base beneficiary premium | $38.99 |
| Penalty percentage (14 months x 1%) | 14% |
| Monthly penalty | $5.46, rounded to $5.50 |
The penalty is added to your plan’s monthly premium. Using the 2027 base premium, the same 14% works out to about $5.79, which rounds to $5.80.
How long it lasts
Medicare.gov says the Part D penalty is added for as long as you have Medicare drug coverage, even if you switch plans. Because it is tied to the base premium, the dollar amount can change each year. Our explainer on how Part D formularies and tiers work covers the rest of the drug benefit.
Who tells you
Your drug plan, not Social Security, informs you of a Part D penalty. Medicare.gov explains that after you join, the plan tells you whether you owe a penalty and what your premium will be. Plans usually ask new members to complete a creditable coverage attestation if records show a gap.
The Part A Penalty for People Who Buy Part A
Most people never face this one, because they qualify for premium-free Part A through 10 years of work.
Who it affects
People who do not qualify for premium-free Part A can buy it. Medicare.gov lists the 2026 Part A premium at $311 or $565 a month, depending on work history.
How it works
If you have to buy Part A and do not sign up when first eligible, your premium may go up 10%. You pay that higher premium for twice the number of years you did not sign up. Medicare.gov’s example: two years without signing up means four years of the higher premium. Unlike the Part B and Part D penalties, it ends.
Who Is Protected From Penalties
Several rules exempt people from penalties. Each comes with conditions, so check how they apply to you.
Job-based coverage from current work
If you or your spouse have group health coverage based on current employment, generally from an employer with 20 or more employees, you can delay Part B and sign up later during a Special Enrollment Period without a penalty. The SEP lasts while you are covered and for 8 months after the job or coverage ends, whichever happens first.
Coverage that does not count includes COBRA, retiree plans, severance-based coverage, individual Marketplace plans and VA health care, according to the SSA. Medicare.gov adds that the 8-month window starts when you stop working, even if you elect COBRA.
Creditable drug coverage
For Part D, any coverage that is at least as good as standard Medicare drug coverage protects you. Employers, unions, TRICARE, the VA and some other plans send an annual notice saying whether coverage is creditable. Keep those notices. You need to join a Part D plan within 63 days after creditable coverage ends to avoid a penalty.
Extra Help
Medicare.gov says you generally do not pay a Part D penalty if you qualify for Extra Help, the federal program that lowers drug costs for people with limited income and resources. For 2026, the limits are $23,940 in income and $18,090 in resources for an individual.
Medicare Savings Programs
Medicare.gov’s penalty page says you generally will not pay a Part B penalty if you enroll in a Medicare Savings Program, the state programs that help pay Part B premiums for people with limited income.
Other Special Enrollment Periods
Medicare.gov lists other situations that create Special Enrollment Periods, such as certain international volunteer work and some exceptional conditions. A SHIP counselor can help you check whether one applies.
Common Ways People End Up With a Penalty
Penalties usually come from a misunderstanding rather than a choice.
- Relying on COBRA or retiree coverage. Neither counts as coverage from current employment for Part B.
- Small-employer coverage. With fewer than 20 employees, Medicare is generally primary and the employer plan may not protect you from the Part B penalty.
- Skipping Part D because you take no drugs. The penalty counts months without creditable coverage, whether or not you needed medication. A low-premium plan can be cheaper than a lifetime penalty.
- Letting the 63-day window pass. After leaving a job with creditable drug coverage, people often wait too long to choose a Part D plan.
- Using discount cards instead of coverage. Medicare.gov notes that drug discount programs are not creditable coverage.
- Marketplace coverage after 65. Keeping an individual Marketplace plan instead of enrolling in Medicare can lead to a Part B penalty and, once you are eligible for premium-free Part A, loss of Marketplace subsidies.
How to Appeal a Penalty You Think Is Wrong
Mistakes happen, especially when records of past coverage are incomplete.
Part D penalty reconsideration
If you disagree with a Part D penalty, Medicare.gov explains that you can ask for a reconsideration. Your plan sends a form with the penalty notice, and you generally have 60 days from the date on the letter to request a review by an independent reviewer that Medicare contracts with. Include proof of creditable coverage, such as employer notices or a letter from your former plan. Keep paying your premium, including the penalty, while the review is pending, so you are not disenrolled.
Part B penalty questions
Part B penalties are handled by Social Security. If you believe you had qualifying job-based coverage or should have had a Special Enrollment Period, contact Social Security and provide proof, such as a completed Form CMS-L564 from your employer, pay stubs showing health premiums or tax forms showing group coverage.
Get help
SHIP counselors give free help with appeals and can be found through SHIPhelp.org or 1-800-MEDICARE (1-800-633-4227).
A Quick Penalty Calculator
You can estimate a penalty with simple arithmetic.
| Penalty | Formula | 2026 example |
|---|---|---|
| Part B | 10% x full 12-month periods without Part B x standard premium | 2 years late: 20% x $202.90 = $40.58 a month |
| Part D | 1% x months without creditable coverage x national base beneficiary premium | 14 months late: 14% x $38.99 = $5.46, rounded to $5.50 a month |
| Part A (if bought) | 10% higher premium for twice the years delayed | 2 years late: 10% higher for 4 years |
Over time the numbers add up. A 20% Part B penalty at the 2026 premium is about $487 a year, and because it rises with the standard premium, it tends to grow each year.
Steps to Avoid Penalties
- Mark your Initial Enrollment Period: three months before your 65th birthday month through three months after.
- If you plan to delay Part B, confirm in writing that your coverage is a group plan from current employment with 20 or more employees.
- Keep every creditable coverage notice from employers and plans.
- When job coverage ends, sign up for Part B within 8 months and join a Part D plan within 63 days.
- Apply for Extra Help or a Medicare Savings Program if your income and savings are limited.
- Ask SHIP for a free review before you skip any part of Medicare.
If you are new to Medicare, our explainer on Medicare Parts A, B, C and D summarizes what each part covers.
Frequently Asked Questions
How much is the Medicare Part B late enrollment penalty?
10% of the standard Part B premium for each full 12-month period you could have had Part B but did not. In 2026, a two-year delay adds $40.58 to the $202.90 standard premium, for $243.50 a month after rounding, according to Medicare.gov.
How is the Part D penalty calculated?
1% of the national base beneficiary premium for each month without Part D or creditable coverage. The base premium is $38.99 in 2026 and $41.33 in 2027, so the dollar amount changes each year.
Do Medicare penalties last forever?
Usually, yes: the Part B and Part D penalties last as long as you have that coverage. By contrast, the Part A penalty lasts twice the number of years you delayed. People under 65 with disability-based Medicare generally stop paying a Part B penalty at 65.
Does COBRA protect me from the Part B penalty?
No. COBRA is not coverage based on current employment, and Medicare.gov says your 8-month Special Enrollment Period starts when you stop working, even if you elect COBRA.
Can I get rid of a Part D penalty?
If you think it is wrong, you can request a reconsideration, generally within 60 days of the plan’s letter, with proof of creditable coverage. People who qualify for Extra Help generally do not pay the Part D penalty.
Sources
- Medicare.gov, Avoid late enrollment penalties (Part A, B and D rules and 2026 examples).
- Medicare.gov, Help with drug costs (Extra Help limits).
- CMS, 2026 Medicare Parts A and B premiums and deductibles fact sheet.
- CMS, Medicare Part D 2027 National Average Monthly Bid Amount fact sheet (July 28, 2026).
- Social Security Administration, When to sign up for Medicare, and More Info: Group Health Plan.
