Read the notice your plan already sent
If you already have Medicare Advantage or Part D, the Annual Notice of Change says what is different for January 1: premium, drugs, doctors, and extras. Last year is not a promise. Why that notice matters is the short version. This fall window is not Medigap Open Enrollment, and it is not the California Birthday Rule.
Write down the care you already use
List each doctor, the office address, the medical group, the hospital you would use, your prescriptions, and your pharmacy. The front-desk worksheet has a line for each answer. Can I keep my doctor? shows what to do with those answers. A $0 premium does not tell you that a doctor is included.
Then look at what is filed
The annual review checklist is the one-page list to print. The 2026 Medicare Advantage list shows plans CMS filed. It does not pick one. The Part D list shows California stand-alone drug plans. It does not look up your drugs. Use Medicare.gov for your prescriptions and your doctors. What you can change in this window is the rule. If you are new to Medicare, this may not be your window. Use which enrollment window am I in?.
Common questions
- Does October 15 apply to a Medicare Supplement?
- No. Annual Enrollment is for Medicare Advantage and Part D. A Supplement uses other windows, including Medigap Open Enrollment and, in California, the Birthday Rule if you already have a Supplement.
- Will the plan list tell me the best plan?
- No. It shows what CMS filed. Your doctors, drugs, and the notice from your current plan are the check. Medicare.gov has the complete list.
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