Critical Enrollment Deadlines for the 2027 Plan Year

Missing federal enrollment windows can result in lifetime late enrollment penalties and delayed healthcare coverage. Marking key transition dates on your calendar ensures your 2027 coverage updates proceed smoothly.

Keep these critical dates in mind as you prepare for the upcoming plan year:

• September 30, 2026: Deadline for your current insurer to mail your Annual Notice of Change (ANOC). This document details changes to your 2027 premiums, copays, and drug formularies.
• October 15 – December 7, 2026: The Fall Open Enrollment Period (AEP). During this window, you can switch between Original Medicare and Medicare Advantage, or change your Part D drug plan.
• January 1, 2027: All new 2027 coverage choices, negotiated drug prices, and adjusted Part B premiums officially take effect.
• January 1 – March 31, 2027: The Medicare Advantage Open Enrollment Period (MA-OEP). Enrollees in an Advantage plan can switch to another Advantage plan or return to Original Medicare.

Reviewing your ANOC letter as soon as it arrives in September gives you ample time to research alternative options before the October enrollment window opens.