Important Dates to Know About Medicare Enrollment and Coverage
Understanding Medicare’s key deadlines can help you avoid costly penalties and gaps in healthcare coverage. Whether you’re approaching age 65 or already enrolled, keeping track of important Medicare dates ensures you make timely decisions regarding your healthcare benefits. Here’s a comprehensive look at the major dates and periods that matter most when it comes to Medicare.
Initial Enrollment Period (IEP)
When: 7 months surrounding your 65th birthday
This is your first opportunity to enroll in Medicare, including Parts A and B. It begins 3 months before the month you turn 65, includes your birthday month, and ends 3 months after.
Missing this window may result in late enrollment penalties, particularly for Part B and Part D, and may delay your coverage start date.
Medicare Supplement Open Enrollment Period (Medigap OEP)
When: 6 months starting the first month you have Medicare Part B and are 65 or older
This is the best time to buy a Medigap (Medicare Supplement Insurance) policy. During this period, you have guaranteed issue rights, meaning insurers cannot deny you coverage or charge more due to health conditions.
After this window, you may be subject to underwriting, higher premiums, or denial of coverage depending on your health.
General Enrollment Period (GEP)
When: January 1 – March 31 each year
If you missed your Initial Enrollment Period and aren’t eligible for a Special Enrollment Period, you can sign up for Medicare Parts A and/or B during the GEP.
Coverage begins July 1, and late penalties may apply for Part B (and Part A if not premium-free).
Annual Enrollment Period (AEP)
When: October 15 – December 7 each year
This is the time to make changes to your Medicare Advantage (Part C) or Prescription Drug (Part D) plans. You can:
- Switch from Original Medicare to Medicare Advantage
- Switch from Medicare Advantage to Original Medicare
- Change from one Medicare Advantage or Part D plan to another
- Enroll in a Part D plan if you missed it earlier
Changes made during this period go into effect January 1 of the following year.
Medicare Advantage Open Enrollment Period (MA-OEP)
When: January 1 – March 31 each year
If you’re already enrolled in a Medicare Advantage plan, you can:
- Switch to a different Medicare Advantage plan
- Return to Original Medicare and enroll in a Part D plan
This is a second chance to make adjustments if you’re unhappy with your Medicare Advantage plan.
Special Enrollment Period (SEP)
When: Varies depending on circumstances
You may qualify for an SEP if you delayed Medicare because you had employer coverage, or due to other life changes like moving, losing coverage, or qualifying for Medicaid.
SEPs allow you to enroll in or change coverage without penalty or waiting for AEP