7 Costly Medicare Enrollment Mistakes (And How to Avoid Every One)
7 Costly Medicare Enrollment Mistakes (And How to Avoid Every One)
By Rodney Denno, RSSA® | Legacy Wealth Services
You’ve worked your entire career for this. The last thing you want is a preventable Medicare mistake eating into your retirement income — permanently.
The harsh reality: Medicare penalties don’t go away. Miss a deadline, make the wrong coverage choice, or fail to coordinate your benefits correctly, and you could be paying hundreds of extra dollars every single month for the rest of your life.
Here are the 7 most expensive Medicare enrollment mistakes I see — and exactly how to avoid every one of them.
Mistake #1: Missing Your Initial Enrollment Window
Your Initial Enrollment Period (IEP) is a 7-month window surrounding your 65th birthday — 3 months before, the month of, and 3 months after. Miss it and you face late enrollment penalties that compound every year.
The penalty: Part B late enrollment costs you 10% added to your monthly premium for every 12-month period you were eligible but didn’t enroll. That penalty is permanent.
Example: If you delay Part B enrollment by 2 years, your premium is permanently 20% higher — that’s an extra $35–$50/month, every month, for life.
The fix: Mark your 65th birthday calendar 4 months out. If you’re turning 65, contact me for a free Medicare review — we’ll map your exact enrollment window and make sure you don’t miss it.
Mistake #2: Assuming Employer Coverage Protects You
Many people think their employer health insurance means they don’t need to worry about Medicare. Sometimes that’s true. Often it’s not — and the consequences are severe.
The key question: Is your employer coverage “creditable” — meaning it meets Medicare’s minimum standards?
If your employer has fewer than 20 employees, Medicare becomes your primary coverage at 65 whether you like it or not. Staying on that small employer plan without enrolling in Medicare Part B is considered a late enrollment — triggering the permanent penalty described above.
The fix: Before your 65th birthday, have your HR department confirm in writing whether your coverage is “creditable” for Medicare Part B purposes. Don’t assume — verify.
Mistake #3: Choosing the Wrong Coverage Type (Advantage vs. Supplement)
Medicare Advantage (Part C) and Medicare Supplement (Medigap) plans are fundamentally different products. Choosing the wrong one for your situation can cost thousands over time.
| Medicare Advantage | Medicare Supplement | |
|---|---|---|
| Monthly Premium | Low (often $0) | Higher ($100–$300+) |
| Network | Restricted (HMO/PPO) | Any Medicare provider nationwide |
| Out-of-Pocket Max | Up to $8,850/year | Near-zero (Plan G covers almost everything) |
| Best For | Healthy, budget-conscious | Those with chronic conditions or frequent care |
The trap: Many people choose Advantage for the low premium, then face thousands in out-of-pocket costs when a serious illness hits. Worse — switching back to a Supplement later may require medical underwriting, meaning you could be denied.
The fix: Don’t choose based on premium alone. We’ll analyze your health status, medications, travel habits, and budget to find the right fit — at no charge.
Mistake #4: Forgetting Part D (Prescription Drug Coverage)
Even if you take no medications today, skipping Part D coverage is almost always a mistake.
The penalty: 1% of the national base premium added to your Part D premium for every month you went without “creditable” drug coverage. That penalty is also permanent.
Example: Skip Part D for 24 months — your drug plan costs 24% more forever.
The fix: Enroll in at least a low-cost Part D plan when you first become eligible, even if you rarely use it. The penalty protection alone makes it worth it.
Mistake #5: Not Reviewing Your Plan Annually
Medicare plans change every year. Premiums, drug formularies, covered providers, and out-of-pocket limits all shift on January 1. Your perfect plan from last year may be your most expensive plan this year.
What changes annually:
- Monthly premiums (can increase significantly)
- Drug formulary (your medication may no longer be covered)
- Network providers (your doctor may leave the network)
- Out-of-pocket maximums
The fix: Every October 15 – December 7 is Medicare’s Annual Enrollment Period. I review every client’s coverage annually at no charge to make sure they’re still in the best plan for their situation.
Mistake #6: Overlooking IRMAA — The High-Income Surcharge
If your income is above certain thresholds, you pay more for Medicare Parts B and D. This is called IRMAA (Income-Related Monthly Adjustment Amount) — and it surprises thousands of retirees every year.
2025 IRMAA thresholds (individual filers):
- Income $103,000–$129,000: +$69.90/month surcharge
- Income $129,000–$161,000: +$174.70/month surcharge
- Income $161,000–$193,000: +$279.50/month surcharge
- Income above $500,000: +$594.00/month surcharge
Important: IRMAA is based on your income from 2 years ago. Just retired and had a high-income year? You may owe IRMAA even though your income has dropped significantly.
The fix: You can appeal IRMAA if your income has dropped due to a “life-changing event” (retirement, divorce, death of spouse). I help clients file these appeals — many get their surcharges eliminated entirely.
Mistake #7: Going It Alone
Medicare has 4 parts (A, B, C, D), 10+ Supplement plan types, hundreds of Advantage plans, and dozens of Part D options in every zip code. The average person spends less than 30 minutes choosing their Medicare coverage — a decision that affects thousands of dollars per year.
Working with an independent Medicare advisor who represents multiple carriers (not just one) costs you nothing. We’re compensated by the insurance companies — your premium is identical whether you work with us or enroll directly.
What you get:
- Unbiased comparison across all available carriers in your area
- Annual review to catch plan changes before they hurt you
- One person who knows your complete coverage picture
Ready to Make the Right Medicare Decision?
Don’t navigate this alone. A 30-minute conversation with me can save you thousands in penalties, premiums, and out-of-pocket costs — and it costs you nothing.
Rodney Denno, RSSA® Legacy Wealth Services [Schedule Your Free Medicare Review →]
Licensed in 26 states. Independent advisor representing multiple carriers.