When Can You Switch Medicare D Plans? 
Medicare Part D Drug Plans can generally only be switched during open enrollment -LRB- Oct 7th - Dec 15th -RRB- . The new plan would become effective Jan 1st 2015 . However , there are SEP 's -LRB- Special Enrollment Periods -RRB- , in which you can make a switch outside of open enrollment . Here are some examples of SEP 's ... You move outside your current plan 's service area , you become eligible for medicaid or a low income subsidy , you have Medicare AND Medicaid -LRB- Medi-Medi -RRB- . 