initial enrollment period (IEP)

Most people enroll in both Medicare Part A (Hospital Insurance) and Part B (Medical Insurance) when they first become eligible — usually at age 65. Your Initial Enrollment Period (IEP) is a 7-month window that starts 3 months before your 65th birthday, includes your birthday month, and ends 3 months after. Enrolling during this time ensures your coverage begins on time and helps you avoid any late enrollment penalties.

annual enrollment period (AEP)

The Medicare Annual Enrollment Period (AEP) happens each year from October 15 to December 7. During this time, you can review, change, or update your Medicare coverage to better fit your current needs. Any changes you make will take effect on January 1 of the following year.

special enrollment period (SEP)

A Special Enrollment Period (SEP) allows you to make changes to your Medicare Advantage or prescription drug coverage when certain life events occur — such as moving to a new area or losing other health insurance. Each SEP has its own rules about when you can make changes and what types of changes are allowed, ensuring you have flexibility when your circumstances change.

open enrollment period (oEP)

If you’re not satisfied with your Medicare Advantage (Part C) plan, you have another chance to make changes during the Medicare Advantage Open Enrollment Period, which runs from January 1 to March 31 each year. During this time, you can switch to a different Medicare Advantage plan (with or without drug coverage) or return to Original Medicare and, if needed, add a Prescription Drug Plan (Part D). Any changes you make will take effect on the first day of the month after you enroll.