Many people are continuing to work into their 60s and 70s. For those seniors who have health insurance through their jobs, things can get confusing when they turn 65: Do you still need Medicare, or should you wait? How does Medicare work when you already have health insurance?

Medicare: The Basics

If you have worked and paid Medicare taxes for at least 10 years, you can get Medicare Part A (hospital coverage) at no cost. You can also choose to also enroll in Medicare Part B (medical coverage), which you will need to pay for each month. Together, Parts A and B are known as “Original Medicare.”

You can also add Medicare Part D (prescription drug coverage) or a Medicare Advantage plan (Medicare Part C), which bundles hospital, medical, and often drug coverage into one plan.

Most people become eligible for Medicare at age 65, even if you’re still working. You don’t always have to sign up immediately, though; if you have health insurance through your job, the right timing will depend on a few factors. 

How Employer Coverage Works with Medicare

If you have health insurance through your job or your spouse’s job, that plan and Medicare can work together. Which one pays first depends on the size of the company (Medicare.gov).

• If the employer has 20 or more employees, your work insurance usually pays first, and Medicare can help cover any costs that are left over.
  

• If the employer has fewer than 20 employees, Medicare usually pays first, and your work insurance pays second.

This difference is important. If you work for a smaller company and don’t sign up for Medicare when you should, you could end up paying more out of pocket, and you might face penalties later when you do enroll.

Deciding Whether to Enroll in Medicare

When you turn 65, you’ll have a few choices about how (or whether) to sign up for Medicare. You can enroll in Part A, Part B, or both (CMS.gov). You can also hold off on enrolling altogether. It all depends on your job situation and what kind of coverage you already have. Here’s how to think it through in simple terms:

Part A: Most people should sign up

If you qualify for premium-free Part A (which most people do), it usually makes sense to enroll when you turn 65, even if you’re still working. It can work alongside your job’s insurance and help cover hospital costs your employer plan doesn’t.

There’s one important exception: if you’re still contributing to a Health Savings Account (HSA), you’ll want to wait to sign up for Medicare. Once you enroll in any part of Medicare, you can’t keep making HSA contributions (NerdWallet).

Part B: Depends on your situation

Part B covers things like doctor visits and outpatient care, and it comes with a monthly premium (in 2024, most people paid around $174.70).

If you’re still covered by your employer’s plan, and that coverage meets Medicare’s standards (what’s called “creditable coverage”), then you can usually hold off on getting Part B without getting a penalty. This makes sense if your current plan already gives you good coverage.

But if your employer has fewer than 20 employees, or if the plan isn’t considered creditable, you’ll want to enroll in Part B when you turn 65. Otherwise, you could face higher costs or late penalties later on.

Part C (Medicare Advantage): An all-in-one option

Medicare Part C, also known as Medicare Advantage, is another option altogether. These plans are offered by private insurance companies and combine Parts A and B, and often Part D (prescription drug coverage), into one plan.

Part C plans can also include extra benefits that Original Medicare doesn’t cover, like dental, vision, or hearing coverage. Whether this is a good fit depends on your personal situation and your employer plan (which might already include those perks).

(We actually wrote a full guide on choosing a Medicare Advantage plan. You can read that here!)  

Part D: Think about your prescriptions

If your employer plan includes prescription drug coverage, check if it’s considered creditable coverage. This means it’s as good as, or better than, Medicare’s standard drug plan.

If it is, you can wait to sign up for Medicare Part D until you leave your job or lose that coverage. But if it’s not creditable, you’ll want to enroll in Part D when you’re first eligible to avoid a late-enrollment penalty.

In short:

• Part A: Usually yes (unless you have an HSA).
  

• Part B: Depends on your job and coverage.
  

• Part C (Medicare Advantage): Optional, but worth comparing.
  

• Part D: Only delay if your current drug coverage is good enough.

Comparing Costs and Options

Even if you like the health plan you have through work, it’s smart to compare the costs and coverage between your current plan and what Medicare offers. Sometimes, Medicare plus a supplemental or Advantage plan can actually save you money. Other times, keeping your work plan until you retire makes more sense.

Here are a few things to consider:

• Monthly costs: Review your Medicare Part B premium versus what you pay for job-based coverage.
  

• Deductibles and copays: How much do you pay out-of-pocket for doctor visits, hospital stays, and prescriptions?
  

• Coverage limits: Are there services Medicare covers that your employer plan doesn’t (or vice versa)?
  

• Dependents: Medicare only covers you, not your spouse or children. If they rely on your employer plan, that might affect your timing.

Timing to Be Mindful Of

Medicare comes with specific enrollment windows, and missing them can mean late penalties or gaps in coverage. Be sure to set reminders so you don’t miss key dates, especially if your work situation changes!

Here’s what to remember:

• Initial Enrollment Period (IEP): This 7-month window starts three months before your 65th birthday month and ends three months after.
  

• Special Enrollment Period (SEP): If you delay Medicare because you’re still covered by a qualifying employer plan, you’ll have an 8-month SEP after that coverage ends to sign up for Part B without penalty.

• Part D and Advantage plan enrollment: You can add or change these plans each year during Medicare’s Annual Enrollment Period (October 15–December 7).

Getting Help

For seniors who are still working, the right Medicare plan depends on your health, your employer’s plan, and your budget, but you don’t have to figure it out alone. A licensed Medicare agent (like us!) can:

• Review your employer coverage to see how it works with Medicare
  

• Help you decide whether to enroll now or later
  

• Compare Medicare Advantage and Supplement plans in your area
  

• Make sure your prescriptions, doctors, and hospitals are covered
  

• Guide you through the paperwork so you don’t miss any deadlines

Whether you enroll in Medicare now or later, planning ahead will help you avoid expensive mistakes and give you peace of mind knowing you’re covered.

At Silver Linings Insurance, we take pride in helping people navigate these choices with clarity and care. Think of us as your personal Medicare concierge; we’re here to simplify the process and make sure you’re confident in your coverage decisions.