Medicare Advantage members get a second window, January 1 to March 31, to switch plans By Tyler Foster, Most retirees think the only chance to fix a Medicare plan comes and goes with the fall enrollment season, but a second window opens every January. The Medicare Advantage Open Enrollment Period runs from January 1 through March 31, giving current Advantage members a chance to correct a choice that has started to look wrong once coverage takes effect. It is a narrower do-over than the fall period, limited in who can use it and how many changes it allows, yet for someone stuck in the wrong plan it can be the difference between a costly year and a manageable one. Who the January window is for This period is open only to people already enrolled in a Medicare Advantage plan as of January 1. It is not a general shopping season, and it does not let someone on Original Medicare jump into an Advantage plan for the first time. The design assumes a member has begun using their plan in the new year, discovered a problem, and needs a route out. That focus is why the rules limit both eligibility and the scope of what can be changed, in contrast to the wide-open fall period. During the window, a member may make one change: switch to a different Medicare Advantage plan, or drop the Advantage plan and return to Original Medicare, with or without adding a standalone Part D drug plan. Someone who returns to Original Medicare can also pick up prescription coverage at the same time, which matters because Original Medicare does not include drug benefits on its own. The change takes effect the first day of the month after the plan receives the request, so a switch made in February generally begins in March.