Annual Enrollment Period (AEP)
The Annual Enrollment Period (AEP) is a recurring Medicare enrollment window that occurs each year from October 15 through December 7. During this period, individuals enrolled in Medicare may review and make changes to certain types of coverage for the upcoming calendar year.
What Changes Can Be Made During AEP
During the Annual Enrollment Period, individuals may enroll in a Medicare Advantage plan, switch from one Medicare Advantage plan to another, return to Original Medicare, or enroll in, change, or drop a standalone Medicare Part D prescription drug plan. Changes made during AEP generally take effect on January 1 of the following year.
Who Is Eligible to Use AEP
The Annual Enrollment Period applies to individuals who are already enrolled in Medicare. It does not replace the Initial Enrollment Period for individuals newly turning 65.
Plan Review Considerations
Because plan premiums, provider networks, formularies, and cost-sharing structures may change annually, individuals often review their coverage during AEP to ensure continued alignment with their healthcare needs. Plan documents such as the Annual Notice of Change (ANOC) outline updates for the upcoming year.
Important Distinction
The Annual Enrollment Period is separate from other enrollment windows such as the Medicare Advantage Open Enrollment Period and Special Enrollment Periods, which operate under different rules and timelines.
Disclaimer: This information is provided for educational purposes only and is based on publicly available guidance from the Centers for Medicare & Medicaid Services (CMS). It has not been reviewed or endorsed by Medicare, CMS, or any federal agency. This content does not constitute plan-specific advice. For individual coverage questions, please consult a licensed insurance professional.