How to Get Medicare While Working?

How to Get Medicare While Working — More Americans than ever are working past age 65, and with that comes one of the most important retirement health questions: “Do I need to sign up for Medicare if I’m still covered by my employer?” The answer depends on your specific situation. At Diversified Insurance Brokers, we help you coordinate employer coverage and Medicare so you can avoid unnecessary premiums, late penalties, and coverage gaps.

Medicare eligibility starts at 65, but enrollment timing isn’t one-size-fits-all. Whether you should enroll right away or delay depends on your employer plan, your company size, your role (employee vs spouse covered under the plan), and whether you contribute to an HSA. Making the right decision can save you thousands over time—and prevent mistakes that are hard to undo later.

How Medicare and Employer Coverage Work Together

When you’re still working, your employer plan may remain your primary coverage—or Medicare may become primary. The biggest factor is typically the number of employees your employer has.

If your employer has 20 or more employees: Your group plan is usually primary and Medicare is secondary. Many people in this situation can delay Part B without penalties, as long as their employer coverage is considered active group coverage. This is also where comparing how Medicare works long-term becomes useful, especially when you eventually leave work and need to choose between Medicare Supplement vs Medicare Advantage.

If your employer has fewer than 20 employees: Medicare is typically primary once you turn 65. In many cases, you’ll want to enroll in Part A and Part B to avoid being underinsured—even if you remain on the employer plan. If Medicare should be paying first and you aren’t enrolled, claims can be delayed or denied, and you could be left paying more out of pocket than expected.

Because employer plan rules vary, it’s smart to confirm how your plan coordinates benefits before making decisions. A quick review of your HR benefits summary can prevent a costly “surprise” later.

Should You Enroll in Medicare Part A While Working?

Many working adults enroll in Medicare Part A at 65 because it is often premium-free if you’ve paid Medicare taxes long enough. Part A can also serve as a backup for inpatient hospital costs, even when your employer plan is primary.

However, there’s a major exception: HSA contributions. If you or your employer contribute to an HSA, enrolling in Part A can create problems because Medicare enrollment generally makes you ineligible to contribute to an HSA. And because Part A can be retroactive in some cases, the timing can get tricky. If this applies to you, review our HSA and retroactive Part A guide before enrolling.

When Do You Need Medicare Part B While Working?

Medicare Part B covers outpatient medical care like doctor visits, diagnostics, outpatient surgery, and durable medical equipment. Unlike Part A, Part B usually has a monthly premium—so the decision to enroll while working should be made carefully.

If your employer has 20+ employees and you have active group coverage, you may be able to delay Part B without penalty. When you stop working (or your employer coverage ends), you’ll typically qualify for a Special Enrollment Period to enroll in Part B without late penalties.

If your employer has fewer than 20 employees, Part B is often essential at 65 because Medicare is primary. Delaying Part B in this scenario can lead to claim issues and late penalties.

What About Medicare Part D While Working?

Part D covers prescription drugs. If your employer plan includes prescription coverage, you’ll want to confirm whether that coverage is considered creditable (meaning it’s expected to pay, on average, at least as much as standard Medicare drug coverage). If it’s creditable, you can usually delay Part D without penalty. If it is not creditable and you delay too long, you could face a permanent late enrollment penalty later.

Even if you keep employer drug coverage now, it’s still wise to plan ahead. When you retire, you’ll need to decide whether to add Part D to a Supplement plan or choose an Advantage plan that includes drug coverage. If you’re comparing structures, our Medicare Advantage vs Medicare Supplement breakdown is a helpful starting point.

Common Mistakes to Avoid

1) Accidentally losing HSA eligibility. If you enroll in Part A (or Part B), you generally can’t continue HSA contributions. Some people enroll automatically when they take Social Security and don’t realize it shuts off HSA funding. If you’re using an HSA strategy while working, plan the timing first.

2) Assuming employer coverage always means “you can delay Medicare.” If your company is under 20 employees, Medicare often becomes primary at 65. This is one of the most common and expensive misunderstandings.

3) Missing the Part B SEP window after retiring. If you delay Part B because you were working, you need to enroll promptly after coverage ends. Waiting too long can result in lifelong penalties and delayed coverage.

4) Not understanding the real difference between Medicare Advantage and Supplement plans. Employer coverage feels like “one plan,” so many people assume Advantage and Supplement work the same way. They don’t. If you’re transitioning off employer coverage, reviewing plan design matters—especially if you want broad provider flexibility or you travel frequently.

5) Not coordinating timing with your spouse. If one spouse is still working and the other is covered on that plan, Medicare decisions may differ for each person depending on coverage, age, and employer size.

Example: Transitioning the Right Way

Consider Michelle, age 66, who works for a company with 35 employees. At 65, she enrolled in Part A but delayed Part B because her employer coverage remained primary and was strong. Two years later, when she retired, she used her SEP to enroll in Part B and then compared plans to find a fit that matched her doctors and budget. Because she acted on time, Michelle avoided late penalties and had no lapse in coverage—while also saving money by reviewing low-cost Medicare plans for retirees.

Estimate Your Medicare Costs

Use our Medicare calculator to estimate costs and compare options. This can help you evaluate premiums, deductibles, and plan direction before you commit—especially if you’re coordinating a retirement date and want your coverage to start smoothly.

Preparing for Retirement and Enrollment

A smart rule of thumb is to start reviewing Medicare options 2–3 months before your planned retirement date. This gives you time to:

Confirm your employer coverage end date and whether COBRA changes anything for Medicare timing
Start Part B enrollment so your effective date aligns with your retirement timeline
Compare Supplement plans (like Plan G) versus Advantage options based on your doctors and travel needs
Make sure prescription coverage is handled properly when employer coverage ends

Many people also explore add-on benefits when leaving employer coverage, such as Medicare plans with dental and vision coverage, so their coverage feels closer to what they had at work.

Need Guidance? Talk with Tonia

If you’re unsure about timing—or you want to confirm whether delaying Part B is truly safe—Tonia Pettitt, our Medicare specialist at Diversified Insurance Brokers, can review your situation and help you move forward with clarity.

Let’s Avoid Costly Medicare Mistakes Together

Book a free consultation with Tonia to ensure your Medicare enrollment is complete, correct, and optimized for your needs.

FAQs: How to Get Medicare While Working

Do I have to enroll in Medicare at 65 if I’m still covered by my employer?

No. If your employer coverage is creditable, you can delay Parts B and D until retirement without penalty.

Should I enroll in Medicare Part A while working?

Usually yes, because it’s premium-free. But if you contribute to an HSA, delay enrollment until after your final contribution.

What happens when I retire or lose employer coverage?

You’ll have an 8-month Special Enrollment Period to sign up for Part B and 63 days for Part D without penalties.

What is “creditable coverage” for Medicare?

It means your employer plan’s benefits are as good or better than Medicare’s. Your HR department can confirm this in writing.

Can I stay on my employer plan and also have Medicare?

Yes. For large employers (20+), your group plan stays primary, and Medicare becomes secondary coverage.

What if my company has fewer than 20 employees?

In that case, Medicare usually becomes your primary insurance once you turn 65, so enrolling in Parts A and B is essential.

Can I keep contributing to an HSA after joining Medicare?

No. Once you enroll in any part of Medicare, you can no longer make HSA contributions. You can still use your funds for qualified expenses.

Will I pay penalties for delaying Medicare?

Only if you go without creditable coverage. Always verify with your employer before choosing to delay enrollment.

Can my spouse enroll in Medicare if I’m still working?

Yes, your spouse can enroll once they turn 65, even if they remain on your employer plan.

Who can help me understand my timing and options?

Tonia Pettitt, our licensed Medicare specialist, offers free consultations to help ensure you enroll correctly and avoid penalties.

About the Author:

Tonia Pettitt, CMIP©, is a seasoned Medicare specialist with more than 40 years of hands-on experience guiding individuals and families through the complexities of Medicare planning. As a senior advisor with the nationally licensed independent agency Diversified Insurance Brokers, Tonia provides clear, dependable guidance across all areas of Medicare—including Medicare Advantage, Medicare Supplement (Medigap), and Part D prescription coverage. Leveraging active contracts with dozens of highly rated insurance carriers, she helps clients compare options objectively and secure the most suitable coverage for their health and budget.

Known for her patient, education-first approach, Tonia has built a reputation as a trusted resource for retirees seeking reliable, unbiased Medicare support. With four decades of experience across evolving Medicare laws, carrier changes, and plan structures, she brings unmatched insight to every client conversation—ensuring clients feel confident, protected, and fully prepared for each stage of their retirement healthcare journey.