Medicare guide
Medicare open enrollment: what you can change
Every fall, you can review your Medicare coverage and switch plans. Here is what the window allows, what it doesn't, and how to check what's changing.
By Dan Huslin, licensed insurance agent · Updated November 2026
When it happens
The Medicare Annual Enrollment Period, also called open enrollment, runs October 15 to December 7 every year. Changes you make take effect on January 1.
What you can do during open enrollment
- Switch from Original Medicare to a Medicare Advantage plan.
- Switch from Medicare Advantage back to Original Medicare.
- Move from one Medicare Advantage plan to another.
- Join, switch or drop a Part D drug plan.
If you leave Medicare Advantage for Original Medicare, you will usually need to add a Part D plan too. And if you also want a Medigap plan, remember that outside your first sign-up window, in most states an insurer can ask health questions and may decline you. Think about that before you switch away from a plan you can't easily get back.
The January to March window
If you're in a Medicare Advantage plan, you get a second chance from January 1 to March 31. You can switch to a different Medicare Advantage plan, or return to Original Medicare and add a drug plan. You can make one change in this window. It doesn't let you move from Original Medicare into Medicare Advantage.
Why review every year
Plans can change their premiums, deductibles, copays, drug lists and networks each year. A plan that worked last year may cover your drugs differently this year. Your plan should send an Annual Notice of Change by the end of September that lists what's changing. Read it before the window opens.
A checklist for your review
- Read your Annual Notice of Change.
- List every prescription you take, with its dose.
- Check that each drug is on the plan's drug list, and what you'd pay for it.
- Check that your doctors, specialists and hospital are still in the network.
- Add up the total cost: premium, deductible, copays and the yearly out-of-pocket limit.
- Check your pharmacy, including mail-order options.
- Compare at least one or two other plans before you decide to stay or switch.
One page, with room to list your prescriptions, doctors and costs.
If your plan hasn't changed and still works for you, you don't have to do anything. Your coverage continues.
I'm happy to go through your notice with you and compare options in the states where I'm licensed. Call me at 619-251-3868 or get in touch. New to Medicare? Start with turning 65: Medicare basics.
This page is general information. For official details, see Medicare.gov or call 1-800-MEDICARE.