Medicare Enrollment Periods

You have finally hit the point in your life when it is time to enroll in Medicare. As much as you would like to deny the entire process and not admit that you are finally 65 or older, it is now time to assess your healthcare and start looking at how and when to enroll into Medicare. Luckily, enrolling in your Medicare is not overly burdensome. However, it can still prove a challenge, especially if you do not know when the enrollment periods for Medicare will be.

Did you know that approximately 700,000 people we’re late and enrolling for Part B of Medicare, according to the Medical Right Center?  Because of this, many had to pay the late enrollment penalty for this part of their Medicare for that year. Even though you have ample time to enroll in Medicare, missing this enrollment date is a fairly common thing to do. This is because there is a lot of confusion with all these enrollment periods.

That’s right, there are multiple enrollment periods. Depending on when you plan to begin your Medicare coverage, you will fall into one of three enrollment periods for starting Medicare Part B. There is even a fourth enrollment periods to make changes to your existing Medicare coverage. Confused yet? Don’t worry, we will help clear this up for you.

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What are the Medicare Enrollment Periods?

The four Medicare enrollment periods are:

  • Medicare Initial Enrollment Period
  • Medicare Special Enrollment Period
  • Medicare General Enrollment Period
  • Medicare Annual Election Period


As you can see, with all these different enrollment periods, you can easily miss your opportunity to get the coverage you need. Let’s take a look at each enrollment period closely.

When Should I Enroll in Medicare?

You have multiple enrollment periods you may be eligible for to initiate your Medicare enrollment. 

  • Initial Enrollment Period: If you are turning 65 and plan to have Medicare as your primary health insurance, you will enroll during your Initial Enrollment Period (IEP). Your IEP begins 3 months prior to the month you turn 65, includes the month you turn 65, and concludes 3 months after the month you turned 65. If you apply in the first 3 months, your Medicare will begin on the month you turn 65. If you apply during the month you turn 65, your Medicare will begin the month after you turn 65. If you apply in any of the 3 months after you turn 65, you Medicare Part B date will vary based on the month you applied. You can apply for either Part A only during your IEP, or both Medicare Parts A and B. If you are applying for both Parts A and B, Medicare will be your primary insurance, so you do not want to have any additional coverage like an employer plan or individual plan.


  • Special Enrollment Period: You may qualify for a Special Enrollment Period (SEP) to enroll in Medicare if you or your spouse continue to work past the age of 65, and you remain on a employer group plan. In order to qualify for an SEP you will need to have when Medicare considers creditable coverage. If you or your spouse continue to work past 65 and want to retain your employer coverage, you will NOT apply for Medicare during your Initial Enrollment Period, but instead apply for a Special Enrollment Period when you retire and terminate your employer coverage. COBRA and retiree coverage do NOT count as creditable coverage.


  • General Enrollment Period: If you did not apply for Medicare during your Initial Enrollment Period and do not qualify for a Special Enrollment Period, you will apply for Medicare during the General Enrollment Period (GEP). The GEP occurs annually from January 1st- March 31st, with coverage beginning on July 1st. If you are required to apply during the GEP, you will likely have a late enrollment penalty for the amount of time you did not have creditable coverage. 
Is it Mandatory to Go On Medicare When You Turn 65?

It is not mandatory to enroll in Medicare at age 65, but there is specific criteria you must meet in order to not be penalized.

If you are 65 but have another form of creditable health insurance through an employer-sponsored plan through either your employer or your spouse’s employer, you can delay your Medicare enrollment. You would later qualify for what is known as a Special Enrollment Period when the employer coverage ends. COBRA and retiree coverage do not qualify as creditable coverage.

If you do not qualify for a Special Enrollment Period and did not enroll in Medicare at age 65 during your Initial Enrollment Period, you must wait until the General Enrollment Period to apply, and will face a lifetime late enrollment penalty.

How Do I Sign Up for Medicare?

There are a few different ways you can enroll in Medicare. 

  • Initial Enrollment Period: If you are applying for Medicare Parts A and B at age 65, you can submit your application online through the Social Security website. If you are already drawing Social Security benefits, you will be automatically enrolled and do not need to submit an application. We have created the link which will take you directly to the Social Security webpage to apply for Medicare. You can also visit your local Social Security office or call 1-800-772-1213 to submit an application. 
  • Special Enrollment Period: If you are applying for Medicare during your Special Enrollment Period, you can still apply online or in person, but you will need to attach the L-564 form to your application. This form is known as the employer-coverage form, and will show that you have delayed your Medicare enrollment due to having creditable health insurance through your employer. 

Medicare Initial Enrollment Period (IEP)

This enrollment time will be the most important period if you plan on beginning your Medicare enrollment as soon as you are eligible. This Initial Enrollment Period is a seven-month long window around your 65th birthday when you can first apply for Medicare Part A and Medicare Part B. The window begins three months before the month of your 65th birthday, includes the month of your 65th birthday, and concludes 3 months following your 65th birthday. In total, you will have a full seven months to enroll in Medicare during this time. If you are already receiving Social Security retirement benefits, or are a member of the Railroad Retirement Board, at age 65, you will be automatically enrolled in Medicare Part A and B for the month of your 65th birthday.

There is, however, one little exception to the rule.  If your 65th birthday happens to be the first of the month, your enrollment period will start one month early.  During this time, you will be able to enroll in Part A and Part B of Medicare. You will also be able to enroll in a Medicare Supplement Plan and Part D Prescription Drug Plan, or Medicare C, commonly known as Medicare Advantage, as an alternative to Original Medicare.


If you want to avoid any late penalties that come with Medicare Part D, make sure you enroll in this drug coverage during the same enrollment window.  This coverage will be a plan on its own, or possibly part of a Medicare Advantage plan that may also include prescription drug coverage.

It is important to remember that although you can applying for Medicare Part A and Medicare Part B at any point during your Initial Enrollment Period, there are strict timelines set by Social Security as to when your Part B will begin based on when you apply. For instance, if you apply in any of the 3 months prior to your birthday, your Medicare Part B will begin on the 1st of your birthday month. However, if you apply during the 3 months following your birthday, your Medicare Part B date varies based on the month you apply:


If you do not qualify to receive Part A premium-free and miss your IEP, you will have to pay a penalty. The cost of the penalty will be twice the number of years you went without Part A once you became eligible for Medicare.

If you don’t enroll in Part B during this time, you will likely have to pay a late enrollment penalty, which will last as long as you have Medicare coverage. You may also have to wait until the General Enrollment Period before you can enroll in Part B. 

If you don’t enroll for Part D during this time, you will also pay a penalty that will last as long as you have coverage.

Give us a call at 877-88KEITH (53484), an experienced agent will walk you through how to determine your Initial Enrollment Period.

What if I Miss the Initial Enrollment?

If you already have creditable coverage through an employer, then signing up late will not be an issue.  However, if you do not have creditable coverage, there are some things you need to consider:

  • There will be a penalty for any late enrollment for Part B after your Initial Enrollment Period. This is going to extend for as long as you have Medicare as your primary coverage.  There’s going to be a 10% penalty for every year you should have had Part B but have failed to enroll.  As of 2024, the initial premium is $174.70.  This can mean that you will pay an additional $17.40 each month.
  • There’s also the chance that you will go with no coverage under Part B for a long time. If you don’t ever sign up during your initial period, you’re going to have to wait until there is another General Election Period. If so, you will not see coverage starting until you apply.
  • If you do not have any Part D drug coverage and miss your enrollment period, you’ll have to pay the penalty with your Part D premium. This will be as long as you have coverage in Part D. This penalty will be 1% per consecutive month that you went without having any coverage for your prescription drugs multiplied by that year’s base modal premium.
  • Suppose for some unforeseen reason that you are unable to qualify for Part A of Medicare as this can be due to not having a large enough work history, and you do not buy into the Medicare program during your enrollment. In that case, you will have to pay a penalty of 10% of your premium for twice the number of years you could have bought the coverage, but you didn’t.

Special Enrollment Period (SEP)

If you are still working past age 65, or your spouse is still working past age 65, and have creditable health insurance under an employer-sponsored plan, you likely do not need to enroll in Medicare when you turn 65.

As long as your employer has more than 20 employees and your plan is considered by Medicare as creditable health coverage (it cannot be COBRA or retiree coverage), you can remain on your plan until you are ready to retire. Once you are ready to retire you can enroll into Medicare, exercising a Special Enrollment Period.

In order to qualify for a Special Enrollment Period, you must have your current employer complete an Employer Coverage Form (CMS L564) showing that you have had coverage under their plan since age 65. If you worked for more than one employer past age 65 with more than one insurance plan, you will need more than one form completed. You will attach this form to your Medicare Part B application when you want to initiate your enrollment. This form will grant the SEP, as well as waive the late penalty from not enrolling in Medicare Part B when first eligible.

You have approximately 8 months following the end of your employer-sponsored health plan to initiate your Medicare Part B coverage. Although 8 months is a large amount of time, Part D Prescription Drug Plans don’t follow the same guidelines. When your employer plan ends, you have 63 days to enroll in a Part D Prescription Drug Plan without facing penalty or having to wait until the Annual Election Period.

Give us a call at 877-88KEITH (53484), an experienced agent will walk you through how to determine if you qualify for a Special Enrollment Period.

Medicare General Enrollment Period

What if I missed my Initial Enrollment Period and don’t qualify for a Special Enrollment Period?

From January 1st through March 31st  of each year, you can participate in the General Enrollment Period. Keep in mind that this will not be a safety net if you miss your other enrollment times.  Even though you can still enroll in Medicare Parts A and B during this period, you’re still going to have to worry about any penalties due to your late enrollment.

On top of these penalties, you will not see your coverage begin until after you apply in the GEP. Your coverage will begin the first of the month following your application. This can mean that you may go a few months without coverage, so it is conducive to ensuring you get coverage during an enrollment period. Especially the Initial Enrollment Period.


It would be best if you remembered that this only applies to Original Medicare.  If you want any of the Medicare Advantage plans or Plan D coverage, you will have to wait for the Annual Enrollment Period.

Annual Election Period


Once you are enrolled in Medicare, whether it is Original Medicare with a Medicare Supplement Plan or a Medicare Advantage Plan, you are probably wondering when you can make changes or enroll in those plans.

Every year, from October 15th through December 7th is the Annual Election Period, also known as open enrollment. This enrollment period is used specifically for making changes to either Medicare Part D Prescription Drug Plans, or Medicare Part C Advantage Plans.

During this time, you can switch from your Original Medicare to a Medicare Advantage plan.  You can also change your Medicare C plan if you’re currently enrolled in one. You can also use this to look into Part D prescription drug plans or even switch to a new one.  Even if you are already enrolled in a Part D plan, you can switch to another if needed, or you can even drop it.  There will be no penalty for you if you’ve already obtained coverage through an employer or another source.

If you are enrolled in a Medicare Supplement plan and want to change to another MediGap plan, or want to change from a Medicare Advantage Plan to a Medicare Supplement plan, you can use this time period, but you will be subjected to medical underwriting. This means that you will need to go through a health assessment in order to apply for a new Medicare Supplement plan if you are more than 6 months past your Medicare Part B start date. Although you can switch from one Medicare Supplement plan to another during this time period, it is wise to apply during another part of the year, as you can change these plans any month of the year with medical underwriting.

October 15th
December 7th
January 1st

Annual Election Period Begins


The Annual Election Period (AEP) begins on October 15th every year. During AEP, Medicare beneficiaries can enroll into, change, or disenroll from Medicare Advantage plans or Medicare Part D plans.


Annual Election Period Ends


The Annual Election Period (AEP) ends every year on December 7th. If you want to enroll into, change, or disenroll from a Medicare Advantage plan or Medicare Part D plan, you must make changes prior to December 7th.


Medicare Plan Changes Become Effective


Any changes made during the Annual Election Period (AEP) will become effective on January 1st of the following year. If you are looking to enroll into, change, or disenroll from a Medicare Advantage plan or Medicare Part D plan, you will want to make changes during AEP to take effect the next year.

Medigap Open Enrollment Period

Even though this isn’t technically a Medicare enrollment period, it is important to note that you have a specific enrollment period for Medicare Supplement plans.

Once you finish enrolling in Medicare part A and B, you will have a chance to qualify for a six-month enrollment window for any Medigap plans that you may need to fill in the gaps in coverage that the other two were unable to cover.  The effective date under your part B coverage will be your election time for your Medigap plans. During this time, you’ll be able to enroll in your plan of choice with no questions asked about your health.

Keep in mind that this will only happen once for most people enrolling in Medicare. So when that is gone, it will be gone for good, so it is not something you want to miss.

Getting the Right Help in Making Your Medicare Choices

You are entitled to Medicare and the other benefits. You worked hard to make sure that you would have healthcare when you finally retire from your job. Keep in mind that it is very crucial to understand that there are going to be rules and regulations when it comes to the benefits and your rights that are under the specific program.

It is vital to learn about all the enrollment periods when it comes to Medicare so that you can take advantage of all the benefits available to you. Unfortunately, if you miss a date, there are consequences that you’re going to have to pay for, and it’s going to be for life. If you have questions regarding your Medicare and what choices you do have, please reach out to a Medicare agent. Many specialize in these types of benefits and services. You can also go to to get even more information to help you make an informed choice and make sure that you do not miss any of the enrollment periods.

After all, you want your retirement to go as smoothly as possible and not have to worry about large bills piling up because of health problems or an emergency room visit.  By making sure you enroll in Medicare at the right time and picking the right plan for your healthcare needs, you’ll be able to rest a little bit easier in your retirement and not have to worry too much about astronomical bills piling up on you.

Holy Cow! You're still here? That's a LOT of periods! Impossible for the average person to know what to do and when to do it. Good news........ I know!
Keith Armbrecht
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