Medicare enrollment periods, including special enrollment, is discussed at https://www.medicare.gov/blog/medicare-enrollment-period-2020
During the open enrollment period, you can:
- Change from Original Medicare to a Medicare Advantage Plan.
- Change from a Medicare Advantage Plan back to Original Medicare.
- Switch from one Medicare Advantage Plan to another Medicare Advantage Plan.
- Switch from a Medicare Advantage Plan that doesn’t offer drug coverage to a Medicare Advantage Plan that offers drug coverage.
- Switch from a Medicare Advantage Plan that offers drug coverage to a Medicare Advantage Plan that doesn’t offer drug coverage.
- Join a Medicare Prescription Drug Plan.
- Switch from one Medicare drug plan to another Medicare drug plan.
- Drop your Medicare prescription drug coverage completely.
Medicare has produced a video describing the open enrollment process at: https://www.youtube.com/watch?v=RGCyPzZBF9s&feature=youtu.be
If you need to sign up for Medicare, that information is here: https://www.medicare.gov/sign-up-change-plans/get-started-with-medicare
If you need a supplement, an advantage plan, or a prescription drug plan, that information is here: https://www.medicare.gov/plan-compare/#/?lang=en&year=2021