A: No. You can change plans every fall from October 15 through December 7. Your new plan starts Jan. 1. If you do nothing during this annual enrollment period, and your plan is offered for the following year, you will remain on the same plan subject to any changes noted for the new year. You also can leave the plan for Original Medicare during this enrollment period and every year from Jan. 1 - Feb. 14. Some people get additional chances to change, or special enrollment periods, for other events (such as moving, qualifying for help with costs, etc.). To switch plans, just enroll in the new plan (do not disenroll from the old plan first). Medicare will disenroll you from the old plan when your new plan starts.
If you choose a Medicare Advantage plan when you first get Medicare and then decide within 12 months it is not right for you, you may have rights to rturn to Original Medicare and buy a Medigap plan instead. Also, if you left a Medigap plan for a Medicare Advantage plan, you might be able to return to that Medigap plan within 12 months. Keep in mind your premium could be different than when you left.