Important Medicare Dates and Enrollment Periods
(AEP, OEP, SEP, and Effective Dates)
Understanding the key dates for enrolling, changing, or reviewing your Medicare coverage is essential. Here's a breakdown of the major periods you should know:
January 1
Start of New Coverage
⦁ If you made any changes during the Annual Enrollment Period (AEP), your new coverage begins today
⦁ If you kept your current plan and it changed its benefits or costs, those changes also take effect today.
Start of New Coverage
⦁ If you made any changes during the Annual Enrollment Period (AEP), your fits or
January 1 – March 31
General Enrollment Period (GEP)
⦁ If you missed enrolling in Medicare Part A and/or Part B during your Initial Enrollment Period (IEP) and don’t qualify for a Special Enrollment Period (SEP), you can sign up between January 1 and March 31.
⦁ Coverage will start the first day of the month after you enroll.
⦁ A late enrollment penalty may apply.
⦁ After enrolling in Parts A and B, you have until June 30 to enroll in a Medicare Advantage (Part C) plan or a Part D Prescription Drug plan.
⦁ Eligibility for enrolling in Medigap plans depends on state regulations.
January 1 – March 31
Medicare Advantage Open Enrollment Period (OEP)
⦁ If you already have a Medicare Advantage (MA) plan:
⦁ You can switch to a different MA plan.
⦁ Or disenroll and return to Original Medicare (and optionally join a stand-alone Part D plan).
⦁ Only one change is allowed during this period.
⦁ Any changes become effective the first day of the following month after your plan receives your request.
Start of New Coverage
⦁ If you made any changes during the Annual Enrollment Period (AEP), your new coverage begins today
⦁ If you kept your current plan and it changed its benefits or
October 15 – December 7
Medicare Annual Enrollment Period (AEP)
During AEP, you can:
⦁ Switch, enroll in, or disenroll from Medicare Advantage plans (MA), Medigap policies, or Medicare Part D Prescription Drug plans.⦁ Return to Original Medicare or join a new Medicare Advantage plan.
⦁ Any changes take effect January 1 of the following year.
⦁ Eligibility for enrolling in Medigap plans depends on state regulations.
Initial Enrollment Period (IEP/ICEP)
⦁ The 7-month window when most people first sign up for Medicare:
⦁ Starts 3 months before your 65th birthday month,
⦁ Includes your birthday month,
⦁ Ends 3 months after your birthday month (assuming you are not delaying Medicare Part B enrollment).
Special Election Periods (SEP)
For Non-Dual Eligibles
⦁ Special enrollment periods may apply if you:
⦁ Move to a new service area,
⦁ Lose group coverage (e.g., employer insurance),
⦁ Your current Medicare plan is discontinued for the next year.
Other Key Dates
September 30:
⦁ Annual Notice of Change (ANOC) Letters must be sent to you.
⦁ ANOC outlines changes to your plan's coverage, costs, and service area effective January 1.October 1:
⦁ Medicare Part D plan details (premiums and coverage information) are published by insurers.October 15:
⦁ You should receive your Evidence of Coverage (EOC) Letter, providing detailed information about your plan's benefits, costs, and services for the next year.
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