5 Mistakes People Make When They First Sign Up for Medicare

We’ve helped over 8,500 people transition to Medicare since 2018. And after walking that many people through the process, we can tell you with complete confidence: almost everyone makes – or almost makes – at least one of these mistakes.

None of them are because people are careless. Medicare is just genuinely confusing. The rules are complicated, the terminology is dense, and the consequences of getting it wrong can follow you for the rest of your life.

Here are the five we see most often – and how to avoid them.

Mistake #1: Assuming Medicare Just “Starts” Automatically

A lot of people think that when they turn 65, Medicare just kicks in. They’ll get a card in the mail, everything will be set up, and they don’t need to do anything.

That’s partially true – but only partially.

If you’re already receiving Social Security benefits before you turn 65, you will be automatically enrolled in Part A and Part B. Your Medicare card will show up in the mail about three months before your 65th birthday. But here’s the catch: even in that scenario, you still need to actively choose and enroll in a Part D drug plan, a Medigap supplement or Medicare Advantage plan, and any ancillary coverage. None of that happens automatically.

And if you’re not receiving Social Security yet? Nothing is automatic. You need to actively sign up for Medicare through Social Security — and if you miss your window, you could face gaps in coverage and permanent penalties.

Your Initial Enrollment Period is a 7-month window: 3 months before your birth month, your birth month, and 3 months after. If you know you need Medicare starting the month you turn 65, sign up during those first 3 months to avoid any delays.

AND – don’t presume that you 100% do need to enroll into Medicare at age 65 – that’s another big mistake. See our TranstionToMedicareGuide.com resource to help you with that question.

The fix: Don’t assume anything. Start the process 3 months before you turn 65, even if you think it’s being handled automatically. Verify everything.

Mistake #2: Signing Up for Part B When You Don’t Actually Need It Yet

This is the flip side of what most articles warn you about — and we see it happen all the time.

Someone turns 65, panics, and signs up for Medicare Part A and Part B because they think they have to. Meanwhile, they’re still working. They still have great employer coverage through a company with 20 or more employees. And now they’re paying $202.90/month for Part B that they didn’t need yet.

That’s over $2,000 a year out of your pocket for something your employer plan was already handling.

Here’s the rule: if you’re still working at 65 and have group health coverage through your employer (or your spouse’s employer) with 20 or more employees, your employer plan is primary. Medicare is secondary. You do not need Part B yet, and you will not face a penalty for delaying it.

When you eventually retire or lose that employer coverage, you’ll get a Special Enrollment Period – an 8-month window – to sign up for Part B without any penalty. That’s your protected window. Use it.

Now, there are situations where it makes sense to sign up for Part B even while working. Maybe your employer plan is expensive and has high deductibles. Maybe you want to move to a Medigap supplement because the coverage is better. Those are valid reasons – but they should be intentional decisions based on math, not a panic move because you turned 65 and assumed you had to.

A few important caveats:

If your employer has fewer than 20 employees, Medicare becomes primary at 65 regardless. You DO need Part B in that scenario. Verify the employer size – don’t guess.

If you’re buying your own individual health insurance – even while employed – that does not count as employer group coverage. You need Part B on time.

If you’re on COBRA, that also does not count. COBRA is continuation coverage, not active employer coverage. You need Part B.

The fix: Before you sign up for anything, find out whether your current employer coverage qualifies you to delay Part B. If it does, you can save thousands of dollars by waiting until you actually need it. And when you do leave that employer coverage, call us immediately – that 8-month Special Enrollment Period clock starts ticking the day your coverage ends, and you don’t want to miss it.

Mistake #3: Skipping Part D Because “I Don’t Take Any Medications”

We hear this one all the time: “I’m healthy. I don’t take anything. Why would I pay for a drug plan?”

Because Medicare will make you pay for not having one. For the rest of your life.

If you don’t enroll in a Part D plan (or have other creditable drug coverage) when you’re first eligible, Medicare charges a late enrollment penalty when you do eventually sign up. The penalty is calculated based on how many months you went without coverage, and it gets added to your Part D premium permanently.

Let’s say you skip Part D for 3 years. That’s 36 months. The penalty in 2026 is roughly 1% of the national base beneficiary premium per month – so about $12–$13 per month added to your premium forever. That might not sound like much, but over 20 years of Medicare, that’s over $3,000 in penalties for a plan that might have cost you $0–$10 per month to begin with.

And here’s the thing: nobody plans to get sick. Nobody plans to suddenly need a $500/month medication. But it happens – and when it does, you’ll want Part D in place. Starting from scratch at that point means penalties and potentially waiting for an enrollment period.

Many Part D plans have $0 premiums. Zero. There is literally no financial reason not to have one.

The fix: Enroll in a Part D plan when you’re first eligible, even if your medicine cabinet is empty. Use programs like GoodRx alongside your Part D plan – sometimes GoodRx beats your copay on certain drugs, and using it doesn’t affect your coverage.

Mistake #4: Choosing a Plan Based on the Premium Alone

This might be the most expensive mistake on the list – not because of a penalty, but because of what it costs you when you actually need care.

We see two versions of this:

Version one: Someone picks a Medicare Advantage plan because the premium is $0. They don’t look at the copays. They don’t look at the network. They don’t look at the maximum out-of-pocket. They don’t check if their doctors are in-network. They just see “$0” and sign up. Then they get hospitalized and owe $2,000. Or their oncologist isn’t in-network. Or they need prior authorization for a procedure and it takes three weeks.

Version two: Someone picks the cheapest Medigap supplement they can find without checking the carrier’s rate increase history. They save $15/month in year one and then get hit with a 20% rate increase in year two because that carrier is known for aggressive pricing followed by steep hikes.

In both cases, the person chose based on one number – the monthly premium – and ignored everything else that actually determines what the plan will cost them over time.

The fix: Look at the whole picture. For Medicare Advantage, that means copays, coinsurance, network, prior authorization requirements, and maximum out-of-pocket. For Medigap, that means the carrier’s rate increase history, not just this year’s premium. Tools like MedigapMath.com can help you copare the real long-term cost of different supplement options.

Mistake #5: Not Getting Help — Or Getting the Wrong Help

Medicare is not a DIY project for most people. There are too many moving parts, too many deadlines, and too many consequences for getting it wrong.

But here’s the other side of that coin: getting the wrong help can be just as bad as getting no help.

The agent at the grocery store seminar who only talks about Medicare Advantage? They might be a captive agent who only represents one carrier. The 1-800 number from the TV commercial? You’ll talk to someone for 15 minutes, get enrolled, and never hear from them again. The friend who says “just do what I did”? Their situation might be completely different from yours.

What you need is an independent agent who represents multiple carriers, will take the time to understand your specific situation, and will be there after enrollment when questions come up – because they will come up.

You need someone who will explain the difference between Medicare Advantage and Medigap without pushing you toward one. Who will tell you about Part D penalties before you skip it. Who will bring up ancillary coverage like cancer insurance and short-term care because those gaps matter. And who will still answer the phone in March when you get a confusing bill.

The fix: Work with an independent agency. Not a call center. Not a captive agent. Not a TV commercial. Someone who works for you, not for the carrier.

That’s what we do. Every day. For every client.

Don’t Learn These the Hard Way

Every single one of these mistakes is avoidable. But they’re only avoidable if you know about them before you make a decision — not after.

If you’re approaching 65 and want to get this right from the start, our free Transition to Medicare Guide covers all of this and more:

TransitionToMedicareGuide.com

And if you want to talk it through with a real person who does this every day, we’re right here.