Medicare & Benefits
Medicare Late Enrollment Penalties (Part B & D), Explained for Families
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Key Takeaways
- A Medicare late enrollment penalty is not a one-time fee. It's added to the monthly premium, usually for as long as your parent has that coverage (Medicare.gov).
- Part B: an extra 10% for each full 12-month period your parent could have had Part B but didn't. Waiting 24 months means a 20% penalty. In 2026 that turns the $202.90 standard premium into $243.50 a month.
- Part D: an extra 1% of the national base beneficiary premium for each month without creditable drug coverage after a gap of 63 days or more. The base was $38.99 in 2026 and is $41.33 for 2027 (CMS).
- Part A penalties apply only to people who have to buy Part A, and they last for twice the number of years your parent could have signed up but didn't.
- Many penalties are avoidable: employer coverage from current work, a Special Enrollment Period, Extra Help, or a Medicare Savings Program can each make a difference.
This guide is general information, not legal or financial advice. Medicare rules have exceptions. Before your parent delays or drops any coverage, confirm the details with Medicare.gov, Social Security, or your State Health Insurance Assistance Program (SHIP).
Here's a conversation that happens in a lot of families. Dad turned 65 a while ago. He felt healthy, he didn't see a doctor much, and signing up for Medicare seemed like something he could get to later. Now he's 67, he needs a knee looked at, and someone at the doctor's office says the words "late enrollment penalty."
If that's where you are, take a breath. The penalty is real, and it often lasts a long time, but it's usually smaller and more predictable than people fear. And if your parent hasn't missed a deadline yet, you may be able to avoid it completely.
Why Medicare charges a penalty at all
Medicare wants people to sign up when they're first eligible, not wait until they get sick. The penalty is the nudge. According to Medicare.gov, late enrollment penalties:
- are added to your monthly premium
- are not a one-time late fee
- are usually charged for as long as you have that type of coverage (for most people, for life), though Part A works differently
- go up the longer you wait
The key phrase in all of this is "coverage similar to Medicare." If your parent had other coverage that counts, the penalty usually doesn't apply. If they had nothing, or coverage that doesn't count, it does.
The three penalties at a glance
| Part A | Part B | Part D | |
|---|---|---|---|
| Who it affects | Only people who must buy Part A | Anyone who delays Part B without qualifying coverage | Anyone who goes 63+ days without creditable drug coverage after first becoming eligible |
| How much | Premium may go up 10% | 10% for each full 12-month period without Part B | 1% of the national base beneficiary premium for each month without coverage |
| How long | Twice the number of years your parent didn't sign up | Usually as long as your parent has Part B | As long as your parent has Medicare drug coverage, even if they switch plans |
| Main ways to avoid it | Special Enrollment Period | Special Enrollment Period; Medicare Savings Program | Creditable drug coverage; Extra Help |
Source: Medicare.gov, "Avoid late enrollment penalties."
Part B: the one most families run into
Medicare.gov describes the Part B penalty this way: your parent pays an extra 10% for each full 12-month period they could have signed up for Part B but didn't.
Worked example (official 2026 figures): Your mother waited 24 full months to sign up for Part B and didn't qualify for a Special Enrollment Period. That's two full 12-month periods, so her penalty is 20%.
- 2026 standard Part B premium: $202.90
- 20% penalty: $40.58
- Total: $243.48, which Medicare rounds to $243.50 a month
Because the penalty is a percentage of the standard premium, the dollar amount changes each year as the premium changes.
A few points that surprise families:
- Partial years don't count. It's each full 12-month period. Eleven months late is not the same as twelve.
- Signing up late can also mean waiting. If your parent missed their Initial Enrollment Period and doesn't qualify for a Special Enrollment Period, they generally sign up during the General Enrollment Period, January 1 to March 31. Coverage starts the month after they sign up (Medicare.gov). That can leave a gap with no Part B coverage at all.
- Income can raise the premium too. The penalty is separate from IRMAA, the extra amount higher-income people pay.
When your parent generally won't owe a Part B penalty
Medicare.gov says that, generally, your parent won't pay a Part B penalty if they qualify for a Special Enrollment Period or if they enroll in a Medicare Savings Program.
The most common Special Enrollment Period is for people who had group health coverage through current employment, their own or a spouse's. When that job or coverage ends, there's generally an 8-month Special Enrollment Period to sign up for Part B without a penalty (Medicare.gov).
Two kinds of coverage often get mistaken for "current employment" coverage. Check carefully before relying on either:
- COBRA
- Retiree health coverage
Medicare.gov notes that the 8-month window starts when the job ends, even if your parent chooses COBRA. If your parent is still working past 65, their HR department and SHIP are the best places to confirm how their coverage counts.
Part D: smaller amounts, but it adds up
The Part D penalty works differently. Your parent owes it if, after their Initial Enrollment Period ends, they go 63 days or more in a row without a Medicare drug plan or other creditable prescription drug coverage. "Creditable" means coverage expected to pay, on average, at least as much as standard Medicare drug coverage.
The penalty is 1% of the "national base beneficiary premium" for each month your parent didn't have coverage. That base changes every year:
| Year | National base beneficiary premium | Source |
|---|---|---|
| 2026 | $38.99 | Medicare.gov |
| 2027 | $41.33 | CMS, announced July 28, 2026 |
Worked example (from Medicare.gov, 2026): Your father waited 14 months after he was eligible to join a drug plan and had no creditable coverage. His penalty is 14%.
- $38.99 × 0.14 = $5.46, rounded to the nearest $0.10 = $5.50 a month in 2026, added to his plan premium.
The same 14 months in 2027: $41.33 × 0.14 = $5.79, which would round to $5.80 a month. (Our own calculation using the CMS 2027 base premium and Medicare.gov's rounding rule.)
The amount is small at first, but it never stops while your parent has Part D, and it follows them if they switch plans. Over 15 or 20 years it becomes real money.
When your parent generally won't owe a Part D penalty
According to Medicare.gov, generally not if your parent:
- had creditable drug coverage, or
- qualifies for Extra Help, the Social Security program that helps pay drug costs.
Tip: Employers and unions usually send a yearly notice saying whether their drug coverage is creditable. Keep those notices. If a penalty is ever charged by mistake, that letter is your proof. Our caregiving documents checklist has a spot for insurance papers.
If you think the Part D penalty is wrong
After your parent joins a drug plan, the plan tells them if they owe a penalty. If you disagree, Medicare's publication on the Part D penalty explains that you can ask for a reconsideration, generally within 60 days of the date on the letter. Include proof of creditable coverage. Keep paying the premium, including the penalty, while it's being reviewed.
Part A: only if your parent has to buy it
Most people get Part A without a premium because they or their spouse worked long enough. CMS says that's about 99% of people with Medicare. The Part A penalty only affects people who have to buy Part A.
If your parent has to buy Part A and doesn't sign up when first eligible, Medicare.gov says the monthly premium may go up 10%, and they'll pay the higher amount for twice the number of years they didn't sign up. Example: eligible for two years but didn't sign up means four years of the higher premium.
How to help your parent avoid a penalty: a checklist
- Mark the Initial Enrollment Period. It runs seven months: three months before the month your parent turns 65, that month, and three months after.
- Find out whether your parent was enrolled automatically. People already getting Social Security benefits before 65 usually are. Look for the red, white, and blue Medicare card.
- If your parent is still working, ask HR two questions in writing: Is this coverage based on current employment? Is the drug coverage creditable?
- Don't let drug coverage lapse for 63 days. If your parent leaves a job or drops a plan, line up the next coverage first.
- Keep every creditable coverage notice and the dates coverage started and ended.
- Check for help paying. Medicare Savings Programs (through your state Medicaid office) and Extra Help (through Social Security) can also prevent penalties.
- Call SHIP before making a change. Counseling is free and SHIP doesn't sell insurance: shiphelp.org or 1-877-839-2675.
Frequently asked questions
Is the Medicare late enrollment penalty for life?
For Part B and Part D, usually yes: it's charged for as long as your parent has that coverage. Part A is different; the higher premium lasts twice the number of years your parent could have signed up but didn't (Medicare.gov).
Can the Part B penalty be waived?
Generally, your parent won't owe it if they qualified for a Special Enrollment Period or enroll in a Medicare Savings Program (Medicare.gov). In limited cases where a federal government error caused the delay, there may be other relief. Ask Social Security or SHIP about your parent's situation.
Does the penalty go away at some point?
The Part B and Part D penalties usually don't. One exception for Part D: people who qualify for Extra Help generally don't pay the Part D penalty.
My parent has Medicare Advantage. Can there still be a penalty?
Yes. Medicare Advantage plans include Part B, so a Part B penalty still applies. If the plan includes drug coverage, a Part D penalty can apply too.
Who do we call to check?
For Part A and Part B enrollment questions, Social Security. For drug plan penalty questions, the plan or 1-800-MEDICARE (1-800-633-4227). For free, neutral advice, SHIP.
Put the dates where you'll see them
Penalties mostly come from deadlines no one wrote down. My book, When You're Caring for a Parent: A Practical Workbook for Adult Children, has fill-in worksheets for organizing medical visits and essential paperwork, so the whole family can see what's due and when. Find it on Amazon in Kindle or paperback.
Related reading: Turning 65: when to sign up for Medicare · 2026 Medicare costs (in Traditional Chinese)
Sources
- Medicare.gov, "Avoid late enrollment penalties": https://www.medicare.gov/basics/costs/medicare-costs/avoid-penalties
- CMS, "Medicare Part D 2027 National Average Monthly Bid Amount Information" (2027 base beneficiary premium $41.33): https://www.cms.gov/newsroom/fact-sheets/medicare-part-d-2027-national-average-monthly-bid-amount-information
- CMS, "Annual Release of Part D National Average Bid Amount and Other Part C & D Bid Information" (July 28, 2026): https://www.cms.gov/files/document/july-28-2026-parts-c-d-announcement.pdf
- CMS, "2026 Medicare Parts A & B Premiums and Deductibles": https://www.cms.gov/newsroom/fact-sheets/2026-medicare-parts-b-premiums-deductibles
- Medicare.gov, "When does Medicare coverage start?": https://www.medicare.gov/basics/get-started-with-medicare/sign-up/when-does-medicare-coverage-start
- Medicare.gov, "The Part D Late Enrollment Penalty" (publication 11222): https://www.medicare.gov/publications/11222-part-d-late-enrollment-penalty.pdf
- CMS, "Late Enrollment Penalty (LEP) Appeals": https://www.cms.gov/medicare/appeals-grievances/prescription-drug/late-enrollment-penalty-appeals
- SHIP: https://www.shiphelp.org
- Medicare.gov, "When can I sign up for Medicare?": https://www.medicare.gov/basics/get-started-with-medicare/sign-up/when-can-i-sign-up-for-medicare
About the Author
Ellen Carter writes practical, plain-language guides for adult children caring for aging parents. She learned most of what she shares the hard way, through her own family's caregiving. Read more about Ellen.