Medicare Advantage Open Enrollment begins on January 1 and runs through March 31. If you choose to switch plans, you can make changes to your Medicare insurance elections during this period. Medicare Advantage, also known as Medicare Part C, is private health insurance that has become so popular that more than half of seniors eligible for traditional Medicare now opt for this alternative, according to KFF. However, the pace of enrollment slowed in 2025.
If you're already an Advantage enrollee, there are only two times a year — spring and fall — when you can switch from one plan to another or return to original Medicare.
