You can change from Medicare Advantage to original Medicare at any time. There is no open or annual enrollment.
The catch is qualifying for a Medicare supplement plan.
In most states once you get past your initial enrollment period (after turning 65 and enrolling in Part A and Part B) you will need to provide evidence of insurability if you want a Medigap plan. It isn't that difficult if you are in reasonably good shape. I can qualify my prospects in about 3 minutes and let them know if they will pass underwriting or not.
The catch is qualifying for a Medicare supplement plan.
In most states once you get past your initial enrollment period (after turning 65 and enrolling in Part A and Part B) you will need to provide evidence of insurability if you want a Medigap plan. It isn't that difficult if you are in reasonably good shape. I can qualify my prospects in about 3 minutes and let them know if they will pass underwriting or not.