What Do I Need To Know About Medicare Open Enrollment? 
I assume you are referring to the annual enrollment that occurs in Oct , Nov and Dec of each year . Open enrollment is a time when those with Medicare Advantage Plans -LRB- MAPD -RRB- and Medicare Part D -LRB- drug plans -RRB- can make a change in their coverage . There are few restrictions and generally no medical underwriting . If you have ESRD you can not enroll in a new MAPD plan . If you have original Medicare and a supplement -LRB- Medigap -RRB- plan , you can change plans at any time provided you are in good health . Some states allow you to change Medigap plans on your birthday or plan anniversary , but most states allow you to make changes only through medical underwriting . 