I remember sitting at my mom’s kitchen table, highlighters in hand, flipping through a thick stack of Medicare mailers that had started arriving like clockwork the minute she turned 64. There were bold claims, friendly fonts, “Act Now” language on nearly every page—and none of it actually helped us understand what she needed.
As a finance editor, I’m used to cutting through fine print. But even I found the process more complicated than it needed to be. And the kicker? Most of the mistakes that cost retirees money aren’t obvious. They’re not about picking the “wrong plan” per se. They’re about timing, assumptions, and a lack of clear, personal guidance.
So let’s change that.
Medicare enrollment doesn’t have to be intimidating. But it does require attention—and ideally, a little friendly strategy before your 65th birthday rolls around.
Mistake #1: Missing Your Initial Enrollment Window
This is the big one. If you don’t enroll in Medicare on time, you could face late penalties—for life.
Here’s how it works:
- Your Initial Enrollment Period (IEP) starts three months before the month you turn 65 and ends three months after.
- If you don’t sign up for Part B (medical coverage) during that window—and you’re not covered by a qualifying employer plan—you’ll pay a penalty for every year you delay.
That penalty is 10% for every 12-month period you were eligible but didn’t sign up—and it sticks around as long as you have Part B.
As of 2024, the average Part B premium is $174.70/month. A 20% penalty would add over $400 per year—for life.
How to avoid it:
- Mark your calendar at age 64 and start researching six months out.
- If you’re still working, check with your HR team to confirm if your coverage qualifies you to delay without penalty.
- If you’re not working (or self-employed without coverage), plan to enroll in Medicare right when your window opens.
Mistake #2: Assuming You Don’t Need Part B Because You're “Healthy”
This one’s sneaky. Many people say, “I don’t go to the doctor much—I’ll wait on Part B.” But Part B is not optional just because you’re healthy—especially if you don’t have employer-sponsored coverage.
Here’s what Part B covers:
- Doctor visits
- Outpatient care
- Preventive services
- Durable medical equipment (like walkers, CPAP machines)
Delaying Part B without qualifying coverage triggers the penalty we just talked about, and means you’ll be uncovered for those services if something unexpected happens.
When it’s okay to delay:
- If you have creditable employer coverage (i.e., your or your spouse’s job provides group insurance), you can delay Part B without a penalty.
But be careful:
- COBRA, retiree coverage, and the Marketplace do not count as creditable coverage for Part B. If you delay based on those, the penalty still applies.
Mistake #3: Confusing Medicare Advantage With Medicare Supplement
This is one of the most common points of confusion—and unfortunately, one of the most expensive if misunderstood.
Let’s break it down:
Medicare Advantage (Part C):
- Replaces Original Medicare (Parts A & B)
- Sold by private insurers
- Often includes drug coverage and extras (dental, vision)
- Lower premiums, but more network restrictions
Medicare Supplement (Medigap):
- Works alongside Original Medicare
- Helps pay for out-of-pocket costs (deductibles, co-pays)
- Higher monthly premium, but broader provider access
People often choose Medicare Advantage because of the lower monthly cost—only to find out their preferred doctors aren’t in-network or that they need pre-approvals for routine procedures.
According to the Medicare Rights Center, over 50% of Medicare Advantage users switch back to Original Medicare within the first five years—often due to unexpected restrictions.
What to do instead:
- Compare not just premiums, but total out-of-pocket costs (including co-pays and deductibles).
- If seeing any doctor nationwide matters to you, consider a Medigap plan with Original Medicare.
- Use Medicare.gov’s Plan Finder tool to preview local options.
Mistake #4: Forgetting to Add Prescription Drug Coverage (Part D)
If you’re not taking any prescriptions, Part D might feel unnecessary. But skipping it? Risky.
Why? Because if you delay enrolling in Part D without other drug coverage (like through the VA or an employer plan), you’ll face a permanent monthly penalty—similar to Part B.
The Part D penalty is calculated as 1% of the “national base beneficiary premium” ($34.70 in 2024) times the number of months you delayed enrollment.
So if you wait two years? You’re adding ~24% to your premium—for life.
Even more important:
- You can’t just add Part D at any time. You need to enroll during your IEP or a special enrollment period—or wait for annual open enrollment.
What to do instead:
- Enroll in a low-cost Part D plan (some start around $8–10/month) even if you don’t take medications now.
- Reassess your plan each year. Formularies change—and so do your prescriptions.
Mistake #5: Not Reviewing Plans Annually
Medicare isn’t a “set it and forget it” system.
Plans change every year: premiums go up, networks shift, medications fall off formularies. What worked for you in 2023 might cost you hundreds more in 2024.
Every fall, during Open Enrollment (Oct 15 – Dec 7), you can:
- Switch from Original Medicare to Advantage (or vice versa)
- Change Part D plans
- Enroll in new plans or drop old ones
And yet? Most people don’t make changes, even when they’re overpaying.
According to the Kaiser Family Foundation, 7 out of 10 Medicare beneficiaries stayed in the same Part D plan in 2023—even though nearly half could have found a cheaper one.
Make it easier:
Set a calendar reminder for early October.
Use the Medicare Plan Finder tool or connect with a licensed SHIP counselor (free, unbiased help).
Check:
Have your medications changed?
Have plan premiums increased?
Are your doctors still covered?
A one-hour check-in can save you hundreds—and keep your care uninterrupted.
Catch It Before It Costs You
There’s no getting around it: Medicare is a system full of deadlines, acronyms, and assumptions that can quietly cost you if you’re not paying attention.
But with a little guidance—and the kind of straight talk you’d want from a friend—you can avoid the worst traps. You can feel confident, clear, and in control of your coverage choices.
So if you or someone you love is nearing 65, take this as your permission slip to slow down, ask questions, and check the boxes that matter. The stakes are too high to wing it—but they’re low enough to get it right with a little support.
You don’t need to become a Medicare expert. You just need to know where the potholes are—and how to walk around them.
