Medicare’s Annual Enrollment Period (AEP) runs from October 15 through December 7, giving you the chance to review, compare, and update your plan for the year ahead (Centers for Medicare & Medicaid Servces [CMS], 2025). But every year, many people miss out on benefits or end up paying more than they need to–All because of simple mistakes.

Here are five of the most common Medicare enrollment missteps and how to steer clear of them.

1. Ignoring Your Annual Notice of Change

• Each fall, your Medicare Advantage or Part D plan sends an Annual Notice of Change (ANOC). It outlines updates to your premiums, copays, and drug coverage f or the upcoming year (Medicare.gov,2025a).
• Don’t Skip it! Even small changes can impact your costs or provider network.

2. Assuming Your Plan Still Fits

• Just because your plan worked last year doesn’t mean it’s still the best fit now.
  Doctor networks, covered medications, and out-of-pocket costs can shift each year (CMS, 2025).
• Take time to review your coverage — or let a licensed agent walk you through what’s new for 2025.

3. Choosing Based on Ads Alone

• Flashy TV ads and mailers often highlight only the best features — not the fine print. 
  
  
• Before enrolling, compare multiple plans side-by-side using the official Medicare Plan Finder tool (Medicare.gov, 2025b) to see what’s actually covered and whether your doctors and prescriptions are included. 
  
  

4. Waiting Until The Last Minute

• The closer you get to December 7, the busier enrollment systems and phone lines become.
• Review early to avoid delays and ensure you have plenty of time to make changes or ask questions (AARP, 2024).
    

 5. Overlooking Prescription Changes 

• • Drug formularies, the list of covered medications, can change annually. 
  • Even one medication moving to a higher tier can cost hundreds more per year (Kaiser Family Foundation [KFF], 2024).
  • Check your prescriptions carefully during your review.

How Harbor Health Can Help

References:

AARP. (2024, September). Medicare Annual Enrollment Period: What you need to know. Retrieved October 16, 2025, from https://www.aarp.org/health/medicare-insurance/

Centers for Medicare & Medicaid Services (CMS). (2025). Medicare & You 2025 Handbook. U.S. Department of Health and Human Services. U.S. Department of Health and Human Services. Retried from https://www.medicare.gov/publications

Kaiser Family Foundation (KFF). (2024, November).Medicare Part D: 2025 formulary and cost trends. Retrieved from https://www.kff.org/medicare/

Medicare.gov (2025a). Annual Notice of Change (ANOC). Retrieved October 16, 2025, from https://www.medicare.gov/

Medicare Rights Center. (2025). *Medicare snapshot: Stories from the Helpline*. https://www.medicarerights.org/media-center/medicare-rights-center-releases-new-medicare-snapshot

Medicare.gov (2025b). Medicare Plan Finder. Retrieved October 16, 2025, from https://www.medicare.gov/plan-compare/

Medicare Disclaimer: We do not offer every plan available in your area. Any information we provide is limited to those plans we do offer in your area. Please contact Medicare.gov or 1-800-MEDICARE to get information on all of your options.