What Is the Medicare Late Enrollment Penalty — And What Happens If You Never Sign Up?
Missing your Medicare enrollment window can cost you money every single month — for the rest of your life. That’s not a scare tactic. It’s just how Medicare works. And the frustrating part is that most people don’t find out about these penalties until it’s too late to avoid them.
A lot of people search for what happens if you never sign up for Medicare — and the honest answer is: you pay more, every month, probably for the rest of your life.
This post breaks down exactly what the Part B and Part D late enrollment penalties are, how they’re calculated, how long they last, and what you can do if you think you might already have one.
Why Medicare Has Late Enrollment Penalties
Medicare is a federal health insurance program, and like any insurance system, it works best when healthy people participate alongside those who need more care. To encourage people to enroll when they’re first eligible — rather than waiting until they get sick — Medicare uses late enrollment penalties as a financial incentive to sign up on time.
The logic is simple: if you delay enrollment, you pay more. Permanently.
The Medicare Part B Late Enrollment Penalty Explained
What Is It?
If you do not sign up for Medicare Part B when you are first eligible, and you do not have a qualifying reason to delay, Medicare may add a late enrollment penalty to your monthly Part B premium.
In most cases, that penalty lasts for as long as you have Part B.
How Is It Calculated?
The Part B late enrollment penalty is 10% of the standard Part B premium for each full 12-month period you were eligible for Part B but did not sign up.
Here’s an example: If the standard Part B premium is $202.90 per month in 2026, and you delayed enrollment for two full years, your penalty would be 20% of $202.90. That adds $40.58 to your monthly premium. Medicare rounds the total to $243.50 per month for 2026.
Because the standard Part B premium can change each year, your penalty amount can change too.
How Long Does It Last?
In most cases, the Part B late enrollment penalty lasts for as long as you have Medicare Part B.
That means it usually does not disappear after a few months or a few years. It stays attached to your Part B premium while you remain enrolled in Part B.
When Does the Penalty Clock Start?
Your Medicare Initial Enrollment Period starts three months before the month you turn 65 and ends three months after the month you turn 65. That gives you a seven-month window.
If you do not enroll in Part B during that window, and you do not qualify for a Special Enrollment Period, the late enrollment penalty clock may start counting the months you went without Part B.
Are There Exceptions?
Yes — and this is where many people get confused.
If you have group health coverage through current employment — either your own job or your spouse’s job — you may be able to delay Part B without a late enrollment penalty.
The key phrase is current employment.
COBRA, retiree coverage, VA coverage, and individual Marketplace plans generally do not count as coverage based on current employment for the Part B Special Enrollment Period.
If you delay Part B because you have qualifying employer group coverage, you can usually sign up for Part B while you are still covered or during the 8-month period after the employment ends or the group health coverage ends, whichever happens first.
The Part D Late Enrollment Penalty
What Is It?
Medicare Part D is prescription drug coverage.
If you go 63 or more days in a row without Medicare Part D or other creditable prescription drug coverage after your Initial Enrollment Period ends, Medicare may add a late enrollment penalty to your monthly drug plan premium.
Creditable coverage means your prescription drug coverage is expected to pay, on average, at least as much as Medicare’s standard Part D coverage.
Many employer plans are creditable, but not all of them are. Before you delay Part D, check with your employer, union, benefits administrator, or plan provider and save any creditable coverage notices you receive.
How Is It Calculated?
The Part D late enrollment penalty is 1% of the national base beneficiary premium for each full month you went without Medicare Part D or other creditable prescription drug coverage.
The national base beneficiary premium changes each year. For 2026, the national base beneficiary premium is $38.99.
So if you went 24 full months without creditable drug coverage, your penalty would be 24% of $38.99, which comes to $9.3576 and rounds to $9.40. That $9.40 would be added to your monthly Part D premium.
Because the national base beneficiary premium can change each year, your penalty amount can change from year to year, too.
How Long Does It Last?
In most cases, the Part D late enrollment penalty lasts for as long as you have Medicare drug coverage.
That means it usually does not go away after a few months or a few years. It stays attached to your monthly drug plan premium while you remain enrolled in Medicare prescription drug coverage.
When Does It Apply?
The Part D late enrollment penalty may apply if you go 63 or more days in a row without Medicare Part D or other creditable prescription drug coverage after your Initial Enrollment Period ends.
This can happen if you did not enroll in a Part D plan when you were first eligible, dropped creditable drug coverage and did not replace it in time, or had drug coverage that was not considered creditable.
This is why it is so important to confirm whether your current drug coverage counts before you delay Part D.
The Difference Between Part B and Part D Penalties
| Comparison point | Part B Penalty | Part D Penalty |
|---|---|---|
| Penalty amount | 10% for each full 12-month period you could have had Part B but did not enroll | 1% for each full month without Part D or other creditable drug coverage |
| How long it lasts | In most cases, as long as you have Part B | In most cases, as long as you have Medicare drug coverage |
| Based on | Standard Part B premium | National base beneficiary premium |
| Key exception | Group health coverage based on current employment | Creditable prescription drug coverage |
What If You Already Have a Penalty?
If Medicare has already added a late enrollment penalty to your premium, you may still have options — especially if you believe the penalty was applied by mistake.
For Part B, contact Social Security if you believe the penalty was calculated incorrectly or if qualifying employer coverage was not counted. You may be able to ask for a review and provide proof of your previous coverage.
For Part D, you can ask for a reconsideration if you believe you had creditable prescription drug coverage during the period in question. You may need documentation from your former employer, union, insurer, or plan provider showing that your drug coverage was creditable.
In both cases, do not ignore the notice. Read it carefully, gather your coverage records, and respond by the deadline listed on the notice.
How to Avoid the Medicare Late Enrollment Penalty
The best way to avoid these penalties is to understand your enrollment windows and act within them. Here’s what to keep in mind:
Know your Initial Enrollment Period. For most people, it begins three months before the month you turn 65 and ends three months after the month you turn 65. Mark it on your calendar well in advance.
Don’t assume your current coverage protects you. COBRA, retiree health plans, VA coverage, and individual Marketplace plans generally do not count as coverage based on current employment for delaying Part B without a penalty. For Part B, the main exception is usually group health coverage through your own or your spouse’s current employment.
Confirm whether your drug coverage is creditable. Your plan should send you a notice each year telling you whether your drug coverage is expected to pay, on average, at least as much as Medicare’s standard prescription drug coverage. Save that letter.
Don’t wait. Even if you’re healthy and don’t think you need coverage right now, the penalty math can work against you quickly. Two full years of delay could mean paying 20% more on your Part B premium for as long as you have Part B.
Frequently Asked Questions
Is there a penalty for not signing up for Medicare?
Yes. If you miss your Initial Enrollment Period and don’t have a qualifying reason to delay — like active employer group coverage through a current job — Medicare can add a permanent penalty to your monthly premium. For Part B, that’s 10% for every 12 months you delayed. For Part D, it’s 1% for every month you went without creditable drug coverage.
How long does the Medicare late enrollment penalty last?
In most cases, for as long as you have that coverage. The Part B penalty stays attached to your monthly Part B premium. The Part D penalty stays with your drug plan premium. Neither one typically goes away on its own.
Can I avoid the penalty if I’m still working at 65?
Possibly — if you have group health coverage through your own or your spouse’s current employer. COBRA, retiree coverage, and Marketplace plans generally don’t qualify. Always confirm before you delay.
Still Not Sure If This Applies to You?
Medicare’s enrollment rules have more exceptions and nuances than most people expect. Whether you’re still working at 65, recently retired, or already enrolled and wondering about a notice you received — it’s worth getting a clear answer before making any decisions.
I’m Robin Dall, an independent Medicare educator and licensed agent serving Florida, Texas, and Arizona. I don’t work for a call center and I’m not going to rush you through a decision. If you have questions about your specific situation, I’d be glad to walk through it with you.
Not connected with or endorsed by the U.S. government or the federal Medicare program. Plan availability varies by location.
