Published: May 16, 2026 · Last updated: May 16, 2026
- Missing your Initial Enrollment Period for Medicare Part B can trigger lifetime late-enrollment penalties of 10% per year you were eligible but not enrolled (CDC, 2024)
- Medicare covers many preventive services with zero copay and zero deductible, but enrollee usage rates are far below the eligible population (CDC, 2024)
- The choice between Original Medicare plus Medigap versus Medicare Advantage is the single largest financial and care decision in the first year, and switching later is harder than most new enrollees realize (NIA, 2024)
Your 65th birthday is approaching. Family members offer conflicting advice. Mail starts arriving from companies you have never heard of, all wanting to enroll you in their plan today. The Medicare.gov site is reasonably clear if you read it slowly, but few people do, and the result is that a high percentage of new enrollees make decisions in the first year that they would change with full information.
Most Medicare mistakes are not catastrophic. Most are recoverable. But several specific errors have long lasting consequences that compound over decades. The 10 mistakes below are the ones that produce the most predictable regret, and most of them are avoidable with 20 minutes of focused attention.
Mistake 1: Missing The Initial Enrollment Period
Your Initial Enrollment Period (IEP) is the 7-month window around your 65th birthday: 3 months before, your birthday month, and 3 months after. If you do not enroll in Part B during this window (or do not have qualifying employer coverage that lets you delay), you may face a permanent late-enrollment penalty of 10% added to your Part B premium for every 12 months you were eligible but not enrolled. The penalty persists for as long as you have Medicare, which is the rest of your life.
The exception is if you have credible employer coverage from active employment (yours or your spouse's). In that case, you can delay Part B without penalty and enroll during the Special Enrollment Period when the employer coverage ends. Retiree coverage and COBRA do not count as credible coverage for this purpose; many people learn this the hard way (CDC, 2024).
Mistake 2: Choosing Medicare Advantage Without Understanding The Trade-Offs
Medicare Advantage (Part C) plans bundle Parts A, B, often D, and frequently extras like dental, vision, and gym memberships. The marketing emphasizes the extras. The trade-offs that get under-discussed: limited provider networks (which can be a serious problem when traveling or when specialists are needed), prior authorization requirements that delay or block specific treatments, and the harder pathway back to Original Medicare with Medigap later in life if your health changes.
Switching from Medicare Advantage to Original Medicare with Medigap later is allowed during annual enrollment windows, but Medigap insurers can apply medical underwriting in most states after your initial 6-month guaranteed-issue window. If you have developed health issues since age 65, you may be unable to get Medigap or may be quoted unaffordable rates. This is the single most consequential decision-asymmetry in the entire system, and many enrollees do not appreciate it until they need to change.
Mistake 3: Skipping The Annual Wellness Visit
Medicare covers an Annual Wellness Visit at no cost (no copay, no deductible) every year after the first. It includes a health risk assessment, cognitive screening, fall risk evaluation, and discussion of a personalized prevention plan. It is not a physical exam in the traditional sense; you can still book a separate physical if you want one.
Despite being free and useful, the Annual Wellness Visit is significantly underused. Many enrollees do not know it exists. Others assume their regular doctor visits cover the same ground (they often do not include the cognitive and fall-risk screening). Schedule it; it is one of the most efficient uses of free Medicare benefits available.
Mistake 4: Not Reviewing Your Plan Annually During Open Enrollment
Plans change. Premiums rise. Drug formularies shift. Provider networks contract. The Medicare Open Enrollment Period runs October 15 to December 7 each year. Most enrollees do not actively review their plan during this window, defaulting to the same plan year after year, which is often no longer the best fit.
The single highest-leverage action during open enrollment is comparing Part D drug plans for your specific medications. The same medication can cost $40 per month on one plan and $250 per month on another. Use the Medicare Plan Finder at Medicare.gov to enter your medications and compare options annually (NIA, 2024).
Mistakes 5 Through 10: Quick Hits
Mistake 5: Assuming Part D is optional. If you do not enroll in a Part D plan during your IEP and later develop a need for medications, you face a permanent late-enrollment penalty (1% of the national base premium per month uncovered).
Mistake 6: Not knowing about Extra Help. The Low Income Subsidy program substantially reduces Part D costs for people with limited income and assets. The eligibility threshold is more generous than most realize (income up to roughly 150% of federal poverty level for full Extra Help, with partial benefits above that).
Mistake 7: Ignoring the IRMAA threshold. Higher income enrollees pay an Income-Related Monthly Adjustment Amount on top of standard Part B and Part D premiums. The threshold for 2026 starts around $103,000 single / $206,000 married filing jointly. Roth conversions and large one-time income events 2 years before enrollment can trigger surprise IRMAA increases.
Mistake 8: Not using the SHIP program. State Health Insurance Assistance Programs offer free unbiased Medicare counseling. The website is shiphelp.org. They can talk you through plan comparisons without the conflicts of interest broker calls bring.
Mistake 9: Confusing Medigap "letters" without knowing the standard. Medigap plans are federally standardized by letter (A through N). Plan G from one insurer covers the same benefits as Plan G from another. Compare on price and customer service, not coverage details.
Mistake 10: Letting agent commissions drive your choice. Medicare brokers are paid commissions that vary by plan. Some plans pay more than others, which can bias recommendations. Use the SHIP program as a second opinion, especially for the Medicare Advantage vs Original Medicare + Medigap decision (NIA, 2024).
To your health,
Ageless Coach
Age Strong. Live Long.
This content is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Reading this article does not create a provider-patient relationship. Always consult your physician or qualified healthcare provider before making changes to your diet, exercise, or health routine. Ageless Coach is not liable for any actions taken based on this information.
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