There is NO such thing as an annual enrollment period for Medicare supplements (Medigap plans).
This is a very common misconception because people get confused about the Annual Election Period that Medicare holds each fall from October 15th – December 7th. During this time, you can change ONLY your Medicare Part D drug plan and/or your Medicare Advantage plan. This period DOES NOT, however, apply to Medicare supplements, also known as Medigap plans.
Medicare supplements are private health insurance policies, just like life insurance. When you first turn 65 or enroll in Part B, whichever comes later, you get a one-time window during which you can buy any supplement and the insurance company cannot turn you down for health reasons. After that six-month open enrollment window passes, you can still apply to change your Medicare supplement; however, you now have to answer the health questions on the application and pass the carrier’s underwriting to be accepted.
It’s important for you to know this if you are new to Medicare and you have health conditions that you feel might cause you to be declined in the future. You will want to try to use your one-time open enrollment window wisely to choose a carrier with a proven track record of low rate increases.
So just remember, the Annual Election Period (AEP) in the fall is for Part D drug plan changes and Medicare Advantage plan changes only. Certainly you could leave a Medicare Advantage plan during this time and apply for a Medicare supplement instead, but in most cases, you will have to pass medical underwriting to be approved for the new supplement – it is not guaranteed that you will be approved for the supplement coverage.