Working Past 65? What You Need to Know About Medicare Enrollment

You can stay on your employer's health plan and delay Medicare, but you must tell Medicare you're doing it

If you're still working at 65 and your employer offers health coverage, you don't have to sign up for Medicare right away. You can keep your work insurance instead. But Medicare needs to know you're doing this intentionally — if you simply don't sign up and don't tell them why, you may face penalties later when you do enroll.

The key is understanding the difference between delaying Medicare because you have employer coverage (which is penalty-free) and just not signing up (which is not). Your employer's plan type matters too: if it's a large employer plan, the rules are more forgiving than if you work for a very small company.

Key Takeaways

• You can delay Medicare Part B and Part D without penalty if you have health coverage through your current employer and that employer has 20 or more employees.
• You must still sign up for Medicare Part A at 65 if you're receiving Social Security, even if you keep your work insurance.
• When you do leave your job or lose employer coverage, you have 63 days to sign up for Medicare without a late-enrollment penalty.
• Tell Social Security or Medicare directly that you're still working and have employer coverage — don't assume they'll figure it out on their own.
• Your employer's HR or benefits department can tell you whether your plan qualifies as "creditable coverage" that lets you delay without penalty.

How employer coverage affects each part of Medicare

Part A (hospital insurance) is the complication. If you're already getting Social Security benefits at 65, you're automatically enrolled in Part A whether you want it or not. You can decline it, but you have to do so in writing. If you're not yet taking Social Security, you can delay Part A enrollment without any penalty.

Part B (doctor visits and outpatient care) and Part D (prescription drugs) are where the delay actually works. If your employer's plan is considered "creditable coverage" — meaning it covers at least as much as Medicare would — you can skip Part B and Part D now and sign up later without paying a penalty. Most employer plans may have access to, but you should confirm with your HR department.

The employer size matters: if your company has 20 or more employees, this protection applies. If it has fewer than 20, Medicare becomes the primary payer, and you should enroll in Part B and Part D at 65 even though you have work coverage.

What "creditable coverage" means and why it matters

Creditable coverage is simply an employer or union health plan that covers prescription drugs at least as well as Medicare Part D does. Your employer's benefits office can tell you whether your plan qualifies — they often include this information in annual benefits summaries or can answer directly if you ask. If they say yes, you're protected from penalties if you delay.

If your coverage is not creditable, or if you're unsure, enroll in Part D anyway when you turn 65. The penalty for late enrollment in Part D can add roughly 1% to your premium for each month you delay, and that penalty is permanent — it stays with you even after you sign up.

Notifying Medicare that you're still working

Contact Social Security or Medicare directly and tell them you're still working and have employer health coverage. You can do this by phone, online, or in person. Social Security's number is 1-800-772-1213. Medicare's enrollment line is 1-800-MEDICARE (1-800-633-4227).

Have your employer's plan name and your employee ID number ready when you call. They will note in your file that you're delaying Part B and Part D based on active employment. This creates a record that protects you from penalties later. If you don't make this call and simply don't enroll, Medicare may assume you missed the deadline and charge you a penalty even though you had a valid reason to delay.

When you leave your job or lose coverage

Once you stop working or your employer coverage ends, you have 63 days to sign up for Medicare Part B and Part D without a late-enrollment penalty. This window is crucial — if you wait longer than 63 days, the penalty applies. Count carefully: the 63 days start the month after your coverage ends or the month after you stop working, whichever is earlier.

Contact Medicare as soon as you know your coverage is ending. You can enroll online at Medicare.gov, by phone at 1-800-MEDICARE, or by visiting your local Social Security office. Have your Social Security number, birth date, and the date your employer coverage ended ready.

What happens to Part A if you're already receiving Social Security

If you're collecting Social Security at 65, you're enrolled in Part A automatically. You can't delay it. You can decline Part A in writing if you want, but this is rarely a good idea — Part A has no monthly premium if you've worked long enough to may have access to, and it covers hospital stays, which are expensive.

If you haven't started Social Security yet, you can delay Part A enrollment along with Part B and Part D. When you do eventually sign up for Social Security, Part A enrollment happens automatically at the same time.

Coordinating with your employer's plan

Your employer's benefits office should know about Medicare rules, but don't assume they do. Ask them directly: "Does our plan count as creditable coverage for Medicare Part D?" and "What happens to my coverage when I turn 65?" Some employers automatically drop you from their plan at 65 and require you to use Medicare instead. Others let you stay on. A few require you to enroll in Medicare Part B first before you can stay on their plan.

Get the answers in writing if possible. If your employer makes a mistake about your coverage or enrollment, having documentation helps you fix it later. Also ask whether your employer offers retiree health coverage — if they do, you may want to understand how it coordinates with Medicare before you leave the job.

Frequently Asked Questions

Do I have to enroll in Medicare at 65 if I'm still working?

Not if you have employer coverage through a company with 20 or more employees. You can delay Part B and Part D. However, if you're already receiving Social Security, you're automatically enrolled in Part A and cannot delay it. Tell Medicare you're still working so they don't charge you a late-enrollment penalty later.

What's the penalty for signing up late?

Part B late-enrollment penalty is roughly 10% of the standard premium for each year you delayed, and it's permanent. Part D penalty is roughly 1% per month of delay. These penalties don't go away once you enroll — you pay them for life. The penalty doesn't apply if you had creditable coverage and notified Medicare you were delaying.

Can I stay on my employer's plan after I sign up for Medicare?

Yes, in most cases. Your employer's plan becomes secondary to Medicare, meaning Medicare pays first and your employer plan covers what Medicare doesn't. Some employers require you to enroll in Medicare first. Ask your HR department what your plan does before you turn 65.

What if my employer has fewer than 20 employees?

Medicare becomes your primary insurance at 65, even if you have employer coverage. You should enroll in Part B and Part D at 65 to avoid penalties. Your employer's plan will be secondary. Contact Medicare to confirm your enrollment status.

How do I know if my prescription drug coverage is creditable?

Your employer's benefits office or HR department can tell you. They often include this information in your annual benefits summary or a separate notice about Medicare. If you can't find it, call them directly and ask: "Is our plan's prescription drug coverage creditable for Medicare Part D purposes?" They should give you a yes or no answer.