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A guide to Medicare enrollment periods: when can I enroll?

Confused about when to enroll for Medicare? In this article, we break down the important dates you need to know.

Illustration of a calendar displaying October 15.

While most Americans become eligible for Medicare when they turn 65, some may become eligible earlier through a qualifying disability or health condition such as ALS or ESRD. If you’re new to Medicare, be sure to also read up on things you should know about Medicare and how to know if you qualify for Medicare.

What are Medicare Enrollment Periods?

Medicare has enrollment periods. These are set windows of time when you can sign up for a plan. Whether you’re gearing up for the big “6-5” and enrolling in Medicare for the very first time, or just trying to remember what all these different periods are, we’re here to help you on your journey. 

Understanding the Initial Enrollment Period (IEP): your 7 month window

Think of your Initial Enrollment Period (IEP) as your personal Medicare shopping window. When you’re turning 65, you will have a 7-month window to sign up for Medicare. The clock starts 3 months before the month you were born in and ends 3 months after your birthday month. 

For example, if you’re set to celebrate your birthday in June, your IEP opens up in early March and closes at the end of September. If you qualify for Medicare at age 65, this is often a common time to sign up for a plan. If you miss your 7-month IEP, you might have to wait to sign up and pay a monthly penalty for as long as you have Part B coverage.

When does my coverage start?

Coverage always starts on the first day of the month, but the actual month may vary depending on when you sign up. 

For example, if you sign up before the month of your 65th birthday, coverage begins the month you turn 65. However, if you sign up the month you turn 65, or sometime during the 3 months after, your coverage would start the next month after signing up. 

Other enrollment periods to remember

General Enrollment Period (GEP) or Open Enrollment Period (OEP)

January 1 - March 31

One question we hear often is, what happens if I miss my initial enrollment period window to enroll in Medicare? The General Enrollment Period (GEP) runs from January 1 - March 31, and is the time for those who missed their IEP to enroll in Medicare Part A and/or Part B. During this time, you can sign up for a plan and coverage would start the month after you sign up. However, there may be a late enrollment penalty involved. 

If you have Medicare Advantage, this time period is known as the Open Enrollment Period (OEP). During this time, you can change your Medicare Advantage plan or go back to Original Medicare. (You can change only once during this period.) 

Annual Enrollment Period (AEP)

October 15 – December 7

The Annual Enrollment Period (AEP) happens every year from October 15th to December 7th. During this time, you’re free to change, drop, or start new Medicare health or prescription coverage. 

If you’re on Medicare Advantage (Part C), you can use this time to choose a new plan, or switch back to Original Medicare for the next year. If you make a change during this time, it will usually become effective January 1st of the following year. 

Special enrollment periods


Medicare and Medicare Advantage plans also let you make changes to your coverage when certain events happen, such as:

  • Moving to a new address that isn’t in your current plan’s service area, or a new location that offers new plan options
  • Losing your current coverage (from Medicaid, from your employer or union, from a drug plan)
  • Your plan’s contract is affected due to a decision from Medicare
  • Being eligible for both Medicare and Medicaid
  • Qualifying for Extra Help

If any of these describe your situation, Medicare could allow you to enroll in a plan year-round. There are other special situations as well that trigger a Special Enrollment Period. 

How do I enroll in Medicare?

Some people get Medicare Part A and Part B automatically, and some have to sign up for it.

If you're already receiving Social Security or Railroad Retirement Board benefits, you can expect a Medicare card in your mailbox about three months before your 65th birthday. You’ll automatically get Part A coverage, and also be signed up for Part B (unless you live in Puerto Rico or outside the U.S.). You don’t have to pay a premium for Part A, but you can choose whether or not you want to keep your Part B coverage.

If Social Security checks haven't started flowing for you, no sweat. You can sign up for Medicare with a few clicks online at the Social Security website, a call to 1-800-772-1213, or by dropping by your local Social Security office for a chat.

The bottom line

When you turn 65, assuming you meet the Medicare eligibility criteria, your Initial Enrollment Period will open. But if the IEP slips by, don’t worry. You will still have the Annual Enrollment Period, the Open Enrollment Period and other Special Election Periods for changes or new plan enrollments. 

Navigating these periods doesn’t have to be something you do alone– we’re always here to help you make the right decision for your health and lifestyle.

How Devoted can help

We have licensed representatives available to help you with your questions or answer more questions about Devoted Health Medicare Advantage plans. Call us at 1-800-483-8066 (TTY 711) for personalized assistance.

You can also learn more about your Medicare options in this free Medicare Comparison Guide.

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