There is never a medical questionnaire when moving from one advantage plan to another. You can always drop an Advantage plan and move back to basic Medicare A/B, but if you want to get a Medicare Supplement, then you are generally required to answer medical questions to determine acceptance. This can also be state dependent.
If you have an Advantage plan, and your plan terminates in the event of a move out of the service area, then you can get a “guaranteed issue” Medicare supplement…meaning no medical questions.
There are other senarios when guaranteed issue applies…but hope this helps.