Medicare Part B Enrollment: When to Sign Up, When You Can Delay Coverage, and How to Avoid Late Enrollment Penalties

One of the most common questions I hear is:

“I’m turning 65, but I’m still working. Do I have to sign up for Medicare Part B?”

The answer is: it depends on the type of health insurance you have.

Some people can safely delay Part B without any penalty. Others could end up paying a higher premium for the rest of their lives if they wait too long. That’s why it’s important to understand the rules before making a decision.

Your First Opportunity to Enroll

Most people become eligible for Medicare at age 65. Your first chance to enroll is during your Initial Enrollment Period (IEP)—a seven-month window that includes:

• The three months before your 65th birthday month
• Your birthday month
• The three months after

If you don’t have qualifying employer health coverage, enrolling during this window is usually the best way to avoid penalties and make sure your Medicare coverage starts on time.

Can You Delay Medicare Part B?

Yes—but only if you meet certain requirements.

In general, you can delay Part B without penalty if:

• You are actively working, and
• You have health insurance through your current employer or your spouse’s current employer.

This allows many people to postpone paying the monthly Part B premium while they continue working.

However, not every employer plan qualifies. Before deciding to delay Part B, it’s important to confirm that your coverage meets Medicare’s rules.

Not All Health Insurance Lets You Delay Medicare

This is where many people get tripped up.

The following types of coverage generally do not allow you to delay Medicare Part B without risking penalties:

• COBRA
• Retiree health coverage
• Individual or private health insurance
• Affordable Care Act (Marketplace) plans
• Veterans benefits alone

If one of these is your only coverage, it’s worth reviewing your Medicare enrollment options before your Initial Enrollment Period ends.

What Happens If You Enroll Late?

If you delay Medicare Part B when you weren’t eligible to do so, Medicare may charge a late enrollment penalty.

The penalty is 10% of the standard Part B premium for every full 12-month period you could have had Part B but didn’t enroll.

For most people, that higher premium continues for as long as they have Medicare Part B, making a simple enrollment mistake surprisingly expensive.

You could also experience a gap in coverage if you miss your enrollment window and have to wait until you’re eligible to sign up.

What If You’re Working Past 65?

If you delayed Part B because you were covered by a qualifying employer health plan, you’ll typically receive a Special Enrollment Period (SEP) when your employment or employer coverage ends.

This gives you an opportunity to enroll in Medicare Part B without a late enrollment penalty, provided you meet Medicare’s eligibility requirements.

Common Mistakes to Avoid

Here are a few mistakes I see most often:

• Assuming any health insurance allows you to delay Medicare.
• Waiting too long after retiring to enroll.
• Believing COBRA protects you from Medicare penalties.
• Waiting until you need medical care before signing up.

The Bottom Line

Every situation is different. Your employer size, the type of insurance you have, and whether you’re still actively working all affect when you should enroll in Medicare Part B.

If you’re approaching 65—or planning to retire soon—it’s worth taking a few minutes to review your options before making a decision. A little planning now can help you avoid costly penalties and unnecessary gaps in coverage later. If you’re unsure whether your employer coverage qualifies, I’d be happy to help you review your situation before you enroll.

We don’t offer every plan available in your area. Any information provided is limited to those plans we do offer. Please contact Medicare.gov, 1-800-MEDICARE, or your State Health Insurance Program to get information on all of your options.