Understanding Your Medicare Enrollment Period

Missing your enrollment period could mean waiting up to one year to make changes to your health plan. Here’s how to avoid that mistake. 

Enrolling in Medicare for the first time is oddly confusing. Enrollment periods are not straightforward, and they can change from year to year, depending on the coverage you choose. Below is a quick guide for what you can and cannot do during your enrollment periods—plus how to be sure you qualify for an enrollment period. 

When Is My Medicare Initial Enrollment Period (IEP)?

Your initial enrollment period (IEP) is a seven-month period that starts three months before your 65th birthday and through the three months after your birthday month

Birthday Enrollment Period
April 12 January 1 through July 31
July 1 April 1 through October 31
November 30 August 1 through February 28

During your initial enrollment period, you should decide a few things:

  • Is signing up for Original Medicare (Medicare Part A and Part B) right now the right choice for you?
  • If you are enrolling, when do you need to enroll?
  • If you are delaying enrollment, how long will you be delaying your enrollment?
  • If you are enrolling, which Medicare coverage option is right for you?

For most people, signing up for Medicare when they’re first eligible is the best decision. Medicare is most often cheaper than even employer health care. Signing up as soon as you are eligible means you won’t risk paying late enrollment penalties, which penalties that last for as long as you have Medicare. 

Still, many people choose to keep their current insurance. For example, if your employer health care covers your whole family, you may want to keep it. This is because Medicare cannot be shared. There is no family plan. 

If this is the case, you need to notify Medicare to move your initial election period. Giving proper notification means you can safeguard yourself from late-enrollment penalties that produce a higher premium (more on this below). Just be sure to follow all the necessary instructions.  

When Does Medicare Coverage Start If I Sign Up During My Initial Enrollment Period?

If you sign up during your IEP before the month of your birthday, your coverage starts on the first day of the month of your birthday. However, if you sign up during the month of your birthday or later, coverage starts on the first day of the following month. 

What Happens If I Miss Signing Up During My Initial Election Period?

If you miss your Initial Election Period, and you didn’t have a qualified reason to delay, you will be penalized on your Part B premium. Nearly everyone has to pay a Part B premium (though Part A premiums are generally free). Late enrollers pay a 10 percent penalty on their monthly premium for every 12 months they delayed coverage. 

When Is My Medicare General Enrollment Period (GEP)?

If you didn’t sign up when you were first eligible for Medicare (and are not eligible for a Special Enrollment Period), you can sign up during the General Enrollment Period (GEP). The GEP lasts from January 1 to March 31 every year. During this time, you can sign up for: 

  • Original Medicare 
  • Medicare Advantage
  • Medicare Part D (Prescription Drug Plan)
  • Medigap

When you sign up for Medicare during the general enrollment period, your coverage starts on July 1 of that year. 

When Is My Medicare Advantage Open Enrollment Period (OEP)?

The Medicare Advantage, also called Medicare Part C, open enrollment is from January 1 to March 31 every year. During this time, you can enroll in Medicare Advantage if you are enrolling in Medicare for the first time. If you already have Medicare Advantage, you can take this period to review your plan and even change plans if you find one that’s more affordable. 

If you have Medicare Advantage but decide to switch back to Orignal Medicare, you can do that during this period. However, you cannot switch from Original Medicare to Medicare Advantage—that’ll have to wait until the Annual Election Period, also called Fall Open Enrollment.  

When Is My Annual Election Period (AEP)?

Also (and confusingly) known as the Fall Open Enrollment, the Annual Election Period is from October 15 through December 7 every year. During this time, you can make changes to your Medicare plan

  • Enroll in a prescription drug plan
  • Switch a prescription drug plan
  • Switch from Original Medicare to Medicare Advantage
  • Switch from Medicare Advantage to Original Medicare

This is also the time to review any changes for the next year. Every year, the Centers for Medicare and Medicaid Services (CMS) review health plans and make changes to care. These changes can involve costs, care covered, the extent of coverage (like the number of therapeutic visits), and more. You will receive an Annual Notice of Change (ANOC) document in the mail in late summer or early fall. 

You should review these carefully so that you’ll know if you need to make changes to your healthcare during your Annual Election Period or Open Enrollment Period

When Can I Enroll in Medicare Part D Prescription Drug Plan?

The best time to enroll in a Medicare prescription drug plan is when you are first eligible for Medicare (during your IEP). You’ll avoid paying any late enrollment fees or penalties that would inflate costs. These added fees will not apply to you if:

  • You have “credible prescription drug coverage” at the time you are first eligible to enroll
  • You are eligible for Extra Help

So the right time to enroll in your Medicare prescription drug plan is when you enroll in Medicare Parts A and B. If you decide to delay coverage, just be sure you follow the rules set by the CMS. When it comes time for you to enroll, be sure to pick out a prescription drug plan, too. 

If you have Medicare Advantage, it may cover your prescription drug plan too. If this is the case, you cannot purchase an additional prescription drug plan. If you do, you may be kicked off your Medicare Advantage plan and reenrolled in Original Medicare, so be careful. 

When Can I Make Changes to Medicare Part D?

If you’re not happy with your current Medicare prescription drug coverage, you can make changes during certain times of the year. You can make changes if your Part D plan ceases—say the health insurance company backing the plan loses its contract with Medicare. In this case, you’d be eligible for a Special Enrollment Period in order to replace your plan.

Special events aside, you can make changes to your prescription drug plan at two other possible times of the year, depending on your health plan:

  • During the Open Enrollment Period, if you have Medicare Advantage
  • During the Annual Election Period, if you have Original Medicare

When Can I Enroll in Medigap?

You can enroll in Medigap, also known as Medicare Supplement Insurance, when you are eligible to enroll in Medicare Part B coverage. Remember that you can only get a Medigap policy if you choose to enroll in Original Medicare. You cannot get Medigap with a Medicare Advantage plan.

When you enroll in Medicare Part B, you are allowed a six-month open enrollment period for enrolling in your Medigap plan. During this time, you can shop, compare, and enroll in the plans you like. You will be protected during the Medigap open enrollment period, meaning a health insurance company can’t deny you or charge you more because of your health conditions. 

After your open enrollment ends, you lose such protections, so don’t delay. 

When Is My Medicare Special Enrollment Period (SEP)?

Some people may be eligible for a Special Enrollment Period. During this time, Medicare beneficiaries are given the chance to enroll or change their health coverage without the risk of penalty. These scenarios include:

  • You’ve moved to an area that makes new plan options available to you or is outside of the service area of your plan. 
  • You’ve moved into or out of an institution such as a skilled nursing facility.
  • You’ve been released from jail or prison. 
  • You’ve returned to the United States after living abroad.
  • You’ve lost Medicaid coverage, employer coverage, union coverage, or COBRA.
  • You’re now eligible for Medicaid, Extra Help, or other government assistance programs.
  • New plan options are made available to you through an employer.
  • You’ve voluntarily or involuntarily lost your prescription drug coverage.
  • Your plan provider has lost its ability to contract with Medicare.
  • You are now eligible for a Special Needs Plan or are no longer eligible for a Special Needs Plan.

Your Special Enrollment Period lasts for eight months. During this time, you can sign up for Medicare or change your Medicare provider, depending on what you qualify for. 

Enrolling in Medicare If You’re on Disability

Medicare eligibility is all about age. If you qualify for disability, you may be able to enroll in Medicare early. If you have end-stage renal disease (ESRD) or amyotrophic lateral sclerosis (ALS, also known as Lou Gehrig’s Disease), you are qualified for Medicare no matter how old you are. 

Otherwise, if you are enrolled in disability benefits, you’ll automatically receive Medicare on the 25th month of receiving benefits. Always be sure to verify that you’ve been signed up correctly. 

Will I be automatically enrolled in Medicare?

If you are drawing your Social Security benefits before you turn 65, you should be automatically enrolled in Medicare Parts A and B. However, you should definitely verify your enrollment. Glitches can happen, and unfortunately, an automatic enrollment glitch can cost you a lot of money. 

What’s the difference between the General Enrollment Period and the Open Enrollment period?

The General Enrollment Period is an initial enrollment period for anyone who missed their initial enrollment. The Open Enrollment Period is an annual enrollment period for anyone who wants to make select changes to their current Medicare Advantage plan (see above for more information).

When should I sign up for Medicare?

You should sign up for Medicare as soon as you are eligible—unless you have a qualifying reason to delay and delaying makes sense to your needs. Medicare is often less expensive than the alternatives, and many people can keep the same doctors they’ve worked with before Medicare.  Delaying can come with late enrollment penalties that add 10 percent (per year of late enrollment!) to your monthly premiums for the life of your Medicare healthcare.  When you sign up for Medicare, be sure to review your options for insurance plans carefully. There are many options available—some may lower your healthcare costs considerably. Taking the time to review your options means you’ll get the best coverage at the best price.  

When can I switch back to Original Medicare?

If you decide that Original Medicare is better for you, you can make the switch during the Annual Election Period that runs from October 15 to December 7 every year. If a special circumstance has prompted you to change your healthcare, you may qualify for a special enrollment period (see above). As a refresher, Original Medicare is made up of two parts. Medicare Part A is your hospital insurance and covers in-patient needs, including skilled nursing facilities. Medicare Part B is your medical insurance and covers office visits and out-patient procedures. 

Conclusion: Enrolling the Right Way the First Time Is Everything

Unfortunately, little mistakes or delays can cost you big time when it comes to Medicare. Many late penalties last as additional fees paid for the life of your Medicare healthcare. However, the windows for signing up and making changes are pretty big, giving you plenty of time to get all the correct paperwork together. 

Updated September 17, 2020

J.J. Starr is a financial copywriter and enjoys helping readers find the information they need. In addition to her background in banking and financial advising, she is also a poet with an MFA from New York University. She lives in Amherst, Massachusetts. You can learn more at jjstarrwrites.com.