There’s a reason so many people feel stuck, overwhelmed, or even scared to make a wrong move.  And it’s not because they’re not trying.  It’s because Medicare is not a user-friendly system.

to make it worse, there are actual traps you can fall into if you don’t know the rules.

Here's 7 big pitfalls I’ve seen people run into.  These aren’t about picking plans; they’re the behind-the-scenes Medicare rules that no one talks about until it’s too late.  My goal is to help you avoid the stress, the penalties, and the hours of phone calls later down the road.

Pitfall #1: Not Having Proof of Creditable Drug Coverage

If you’re still working at 65, you might think, “I’ll just get Medicare Part A now (it’s free) and I’ll deal with the rest later.”

Here’s the catch: Once you get Part A, Medicare assumes you’re also ready for a drug plan (Part D).  That’s your “initial eligibility” for drug coverage, even if you’re still on your work plan and don’t actually need a Part D plan yet.

So how do you avoid a late penalty down the line?

• You’ll need to prove your employer coverage included “creditable” drug coverage, meaning it was as good as Medicare’s.  If you don’t respond to that request (usually a letter from your new drug plan when you sign up), you’ll get stuck with a monthly penalty that never goes away.

Most people don’t even realize this until they notice their drug plan premium is way higher than expected and by then, it’s a mess to unravel.

• Tip: If your employer sends you a letter that says your drug coverage is creditable, hang onto it.  File it away, screenshot it, do whatever you need to do to keep it handy when you finally sign up for Part D.

Pitfall #2: Staying on a Marketplace Plan After Turning 65

This one breaks my heart because it happens a lot.

If you’re getting a good deal on a Marketplace plan, (maybe even free because of the subsidy), it’s super tempting to just stay on that plan when you turn 65 and skip Medicare for now.

But once you're eligible for Medicare, you’re no longer eligible for that subsidy.  Even if your Marketplace plan doesn’t cancel you automatically, you’re still technically in the wrong system, and eventually, someone catches the mistake.

I've seen folks:

• Get hit with a tax bill for all those months of subsidies they weren’t supposed to get.
• Have their Marketplace plan canceled retroactively, meaning all the care they received has to be paid back out of pocket.
• And on top of that, end up with a Medicare late enrollment penalty.

• Bottom line: Marketplace plans and Medicare don’t mix.  Once you’re Medicare-eligible, it’s time to make the switch, no matter how tempting it is to stay.

Pitfall #3: Enrolling in Part A While Still Contributing to an HSA

Here’s a lesser-known trap that catches a lot of people who are working past age 65.

Let’s say you’ve got a high-deductible health plan through work and you’re putting money into an HSA (Health Savings Account). If you decide to enroll in just Medicare Part A while still working, (because it’s free, right)? You’ve now crossed the line where you’re no longer allowed to contribute to that HSA.

And it gets even messier: Part A is retroactive up to 6 months if you enroll after age 65. So if you don’t time things right, you could be facing tax penalties for “illegal” HSA contributions you didn’t even know were illegal.

• Tip: If you’re still working and want to keep contributing to your HSA, hold off on Part A.  And when you do enroll in Medicare, stop contributing at least 6 months beforehand.

Pitfall #4: Signing Up for an Advantage Plan When A and B Start on Different Dates

This one’s so strange, but it happens more often than you’d think.

If your Part A and Part B didn’t start at the same time, and you’re trying to get onto a Medicare Advantage plan, it gets tricky. The plan has to start on the same day your Part B starts, or within a 2-month window of leaving your group plan.

Here’s a real-life story: I worked with someone I'll call Pat.  Her group plan ended in October, but she didn’t start Part B until February. By the time she was ready to pick an Advantage plan, her window had closed.   Pat would’ve had to wait until the fall Annual Enrollment Period, but she got lucky.  Her zip code had a 5-star plan (not that common), and she was able to use that to enroll outside the window.

• Lesson: Always double check your enrollment windows if your A and B start dates don’t match up. This one can sneak up on you.

Pitfall #5: Missing Your One-Time Medigap Open Enrollment Window

This one is big, especially for those who want the flexibility of a Medigap plan.

When your Part B starts, you get a six-month window to sign up for any Medigap plan, no health questions asked.  After that, unless you live in a special state like New York, Connecticut, Massachusetts, or Vermont, you could be denied based on your health.

So here’s what I see a lot: people go with a Medicare Advantage plan first because it’s cheaper upfront. Then, a few years later, they want to switch to Medigap, but can’t.

• Tip: Just be aware that you may not get a second chance at Medigap without answering health questions.  If you’re leaning toward Medigap, it’s smart to lock it in from the start.

Pitfall #6: Trying to Cancel and Restart Part B Just to Change the Start Date

This is one of those situations where trying to fix a small mistake creates a much bigger problem.

Say you applied for Part B and didn’t realize it would start the next month. You think, “No problem, I’ll just cancel it and pick a new start date.”

Here’s why that’s risky: the time it takes to cancel and reapply can be longer than the window you’re trying to shift. Meanwhile, your whole Medicare timeline gets thrown off. You may not be able to enroll in supplemental coverage. You may not even be sure if you have coverage while you wait.

• Tip: If you're applying for Part B after age 65, always write your preferred start date in the remarks section of the form. That’s the cleanest way to avoid this whole mess.

Pitfall #7: Medicare Still Lists Your Group Plan as Primary After You Retire

This one is showing up more and more lately.

If you’ve been on a group health plan and then retire, Medicare is supposed to take over as primary.  But sometimes Medicare’s system still shows your old employer plan as the one that pays first, even though it doesn’t.

The result? Medicare denies your claims. Your supplement doesn't pay it's part.  And you’re left with bills no one is paying.

• Tip: Once your new coverage starts, log into your Medicare account and make sure your old group plan isn’t still listed.  If it is, call the Benefits Coordination and Recovery Center at 📞 1-855-798-2627 to get it corrected.

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You deserve to feel in control of this process, and that’s exactly what I’ll help you do.

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