You can delay Medicare enrollment past 65 if you have employer health coverage, but you need to understand the rules to avoid penalties

If you are still working and covered by your employer's health plan, you do not have to sign up for Medicare at 65. You can delay enrollment without penalty as long as you meet specific conditions. The key rule: your employer must have at least 20 employees, and you must be actively employed — not retired and collecting a pension. If both are true, you can wait to enroll in Medicare Part A and Part B until you leave your job or lose the coverage.

The catch is that different parts of Medicare have different rules. Part A (hospital insurance) and Part B (medical insurance) follow the active employment rule. Part D (prescription drug coverage) does not — if you go without it while working, you will owe a penalty when you do sign up, even if your employer covers prescriptions. Understanding which parts you can delay and which you cannot is the difference between saving money and paying extra for years.

Key Takeaways

  • You can delay Part A and Part B enrollment past 65 without penalty only if your employer has at least 20 employees and you are actively working there.
  • Part D (prescription drug) has no active employment exception — going without coverage for more than 63 days triggers a lifetime penalty, even if your employer covers drugs.
  • You have eight months after you leave your job or lose coverage to sign up for Part A and Part B without penalty, called the Special Enrollment Period.
  • If you miss the eight-month window, you will owe a permanent increase to your Part B and Part D premiums for as long as you have Medicare.
  • Notify Social Security or Medicare at least one month before your coverage ends so your enrollment window starts on time.

How the active employment exception works

The active employment exception lets you stay on your employer's plan instead of Medicare Part A and Part B. Your employer's plan becomes primary — it pays first — and Medicare becomes secondary. This only works if three things are true: you are under 65 (or exactly 65 and still actively working), your employer has at least 20 employees, and you are employed there, not retired.

Part-time work counts as active employment. Consulting or contract work does not, unless you are on the company's payroll as an employee. If you own the business or are self-employed, the exception does not explore — you cannot count your own employees toward the 20-employee threshold. Once you retire, even if you stay on the company's health plan as a retiree, the exception ends and you must enroll in Medicare within a specific timeframe or face penalties.

Your employer's plan does not have to be better than Medicare. You can use the exception even if the coverage is minimal. The point is that you have creditable coverage — coverage that meets federal standards — so you are not going uninsured while you work.

The Part D prescription drug rule has no employment exception

Part D is different. There is no active employment exception for prescription drug coverage. If you turn 65 while working and do not enroll in Part D, you will owe a penalty when you eventually do sign up — even if your employer covers prescriptions just as well as Medicare Part D would.

The penalty is 1% of the national average Part D premium for each month you were without coverage. If you go without Part D for two years, the penalty is roughly 2% of the average premium, and you pay it for the rest of your life. The penalty is added to your Part D premium each month, so it compounds over time.

The exception is if your employer's prescription coverage is creditable — meaning it is at least as good as Medicare Part D. If it is, you can skip Part D without penalty. Your employer should tell you in writing whether the coverage is creditable. If you are unsure, ask your benefits department or call Medicare at 1-800-MEDICARE to confirm.

What happens when you leave your job or lose coverage

When you stop working or lose your employer coverage, you enter a Special Enrollment Period that lasts eight months. During this time, you can sign up for Part A and Part B without penalty, even if you are past 65. You do not have to wait for the standard open enrollment period in October and November.

The eight-month clock starts the month your coverage ends. If you lose coverage on June 30, your window runs from July through February. You can enroll any time during those eight months. However, the sooner you enroll, the sooner your coverage starts — there is usually a one-month lag between when you sign up and when coverage begins.

If you miss the eight-month window, you will owe a permanent penalty on your Part B premium. The penalty is 10% of the national average Part B premium for each year you were without coverage. If you waited three years past 65 to enroll, you pay 30% extra on your Part B premium for life. The same penalty applies to Part D if you did not have creditable coverage while working.

How to notify Medicare before your coverage ends

Contact Social Security or Medicare at least one month before your coverage ends. You can call Social Security at 1-800-772-1213 or Medicare at 1-800-MEDICARE. Have your Social Security number, date of birth, and employer information ready. Tell them the date your coverage will end.

You can also sign up online at Medicare.gov if you have a Medicare.gov account. Log in, go to "Manage Your Health Coverage," and select "Report a life event." Choose "I lost my employer health coverage" and enter the date it ends. The website will walk you through the enrollment steps.

If you sign up before your coverage ends, Medicare will usually start your coverage the first day of the month after your employer coverage ends. If you wait until after your coverage ends, there may be a gap. Notifying early prevents confusion and ensures your coverage starts on time.

What to do if you already missed the important date

If you are past 65 and did not enroll in Part A and Part B within eight months of losing coverage, you have missed the Special Enrollment Period. You now owe a permanent penalty on your Part B premium — 10% for each year you were without coverage. The same applies to Part D if you did not have creditable drug coverage.

You can still enroll, but the penalty stays with you. You can enroll during the standard open enrollment period (October 15 to December 7 each year), and coverage will start January 1. Or you can ask Social Security or Medicare whether you may have access to for a Special Enrollment Period based on your specific situation — some circumstances, like losing coverage due to a change in your employer's plan, may reopen the window.

If you believe you have a valid reason for missing the important date, contact Social Security at 1-800-772-1213 and ask to speak with a representative about your situation. Bring documentation of when your coverage ended and why you did not enroll. It is worth asking, because some situations do may have access to for an exception.

Comparing your employer plan to Medicare before you leave

Before you retire or leave your job, compare what you will pay under your employer plan versus Medicare. Look at premiums, deductibles, copays, and out-of-pocket limits for both. Medicare Part B has a standard premium (which changes each year), a deductible, and 20% coinsurance for most services. Your employer plan may be cheaper or more expensive depending on your health and the services you use.

Also check whether your doctors and hospitals accept Medicare. Some providers do not, and if your current doctors do not accept Medicare, switching to Medicare means finding new providers. Ask your doctors' offices directly whether they accept Medicare patients.

If you are on your employer's retiree health plan, check whether it coordinates with Medicare or replaces it. Some retiree plans are secondary to Medicare (Medicare pays first), while others are primary. This affects how much you pay out of pocket. Your benefits department can explain how your specific plan works.

Frequently Asked Questions

Can I stay on my employer plan after I turn 65 if I keep working?

Yes, if your employer has at least 20 employees and you are actively employed there. Your employer plan becomes primary and Medicare becomes secondary. You do not have to enroll in Medicare Part A or Part B. However, you must still enroll in Part D or have creditable drug coverage to avoid a penalty.

What if my employer has fewer than 20 employees?

The active employment exception does not explore. You must enroll in Medicare Part A and Part B at 65, even if you are still working. If you do not, you will owe a permanent penalty on your Part B premium. You should also enroll in Part D unless your employer's drug coverage is creditable.

Do I have to enroll in Part D if my employer covers prescriptions?

Only if the coverage is not creditable. If your employer's drug coverage is creditable — as good as Medicare Part D — you can skip Part D without penalty. Ask your benefits department in writing whether your coverage is creditable. If it is not, enroll in Part D to avoid a lifetime penalty.

What if I retire but stay on my employer's retiree health plan?

Once you retire, the active employment exception ends. You have eight months from the date your active employment ends to enroll in Medicare Part A and Part B without penalty. Your retiree plan may continue, but it becomes secondary to Medicare. Enroll in Medicare within the eight-month window to avoid penalties.

Can I get my Part B penalty waived if I did not know about the rule?

Not automatically, but you can ask. Contact Social Security at 1-800-772-1213 and explain your situation. Some circumstances, like language barriers or lack of notice from your employer, may may have access to you for an exception. You will need documentation to support your request.