Medicare Open Enrollment (October 15 to December 7): What You Can Change
Learning goal: Know what you can change during Medicare's yearly Open Enrollment, the separate Medicare Advantage Open Enrollment, and what to review each fall.
Short answer
From October 15 to December 7 each year, you can join, drop or switch Medicare Advantage and Part D plans, or move between Original Medicare and Medicare Advantage. Changes start January 1. If you're already in Medicare Advantage, you get another chance from January 1 to March 31 to switch plans or return to Original Medicare.
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On this page
The Fuller Picture
Plans can change their costs, networks and drug lists each year, so review your plan's Annual Notice of Change each fall. Remember that switching back to Original Medicare doesn't by itself give you a right to buy Medigap without underwriting. If you joined Medicare Advantage during your Initial Enrollment Period, you also have your first 3 months to change.
Key Takeaways
- Medicare.gov lists the Open Enrollment Period as October 15 to December 7.
- You can join, drop or switch Medicare Advantage and drug plans, and move between Original Medicare and Medicare Advantage.
- Coverage starts January 1; the plan must get your request by December 7.
- The Medicare Advantage Open Enrollment Period runs January 1 to March 31, only if you're already in Medicare Advantage.
- Review your plan's changes each fall; costs and drug lists can change.
Real-World Example
Grace
Grace's Part D plan raises the cost of her main medication for next year, according to its fall notice. In November, she compares plans with her prescriptions, finds one that covers the drug at a lower cost at her pharmacy, and switches by December 7. Her new plan starts January 1.
Common Mistakes
- Not reading the plan's yearly notice of changes.
- Missing December 7.
- Switching from Medicare Advantage to Original Medicare without checking Medigap rules.
- Comparing drug plans without entering your actual prescriptions.
Interactive Exercise
Your Fall Medicare Review
Do this each year before December 7.
Tick each step as you do it. Your checklist is saved in this browser.
Knowledge Check
Question: During Medicare's October 15 to December 7 Open Enrollment, which change can you make?
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- Insurance Preparedness Checklist: Twelve insurance questions worth having an answer to, with a place to learn more about each one you have not looked at yet. No score.
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Questions to explore next
Questions readers often ask next about this topic:
- Should I change my Medicare plan this year?
- What changed in my plan for next year?
- Which drug plan is cheapest for my prescriptions?
- Can I go back to Original Medicare?
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The factual claims on this page were checked against these sources. Rules and figures change, so check the source itself if you need to confirm the current version.
- medicare.govJoining a health or drug plan · Medicare.gov (U.S. Centers for Medicare & Medicaid Services)
Educational information, not advice: This lesson is for general education only, not legal, financial, or insurance advice. Actual coverage, discounts, and requirements depend on your policy’s wording, your insurer, and the laws of your state. Confirm specifics with your own insurer or a licensed agent before making a decision. Insurpedia does not sell insurance and does not recommend specific insurers. Rules and 2026 figures are from Medicare.gov. Figures change each year, and your situation may differ. For personal help, contact your State Health Insurance Assistance Program (SHIP) or Social Security. Educational information, not advice.