Annual Enrollment Period (AEP)

The Annual Enrollment Period (AEP) runs every year from October 15 through December 7. This is the most important Medicare enrollment window of the year. During AEP, anyone with Medicare can make changes that take effect January 1.

During AEP you can: switch from Original Medicare to a Medicare Advantage plan (or back), change from one Medicare Advantage plan to another, join, switch, or drop a Part D prescription drug plan, and add or drop Medigap coverage (subject to underwriting in most states).

Changes made during AEP take effect January 1 of the following year. If you do nothing during AEP, your current coverage rolls over automatically — but plan benefits, premiums, and formularies may change year to year, so it pays to review your options every fall.