For most people, enrolling in Medicare Part A will be very easy. Part A offers a premium-free version that most people qualify for, and enrollment for many is automatic. However, understanding your enrollment options is essential, especially if you want to change your coverage, switch to Medicare Advantage, or if you have to pay Part A premiums. We’ll run through everything you need to understand before and after you enroll.

Understanding Medicare eligibility

Before you enroll in Part A, you have to be eligible. Most people become eligible when they turn 65, but there are also a few other situations in which you can become eligible for Medicare.

If you have end-stage renal disease (ESRD) or amyotrophic lateral sclerosis, also known as ALS or Lou Gehrig’s Disease, there are special rules that apply. These situations vary, but your coverage will generally begin when you begin receiving disability benefits. You can read about them in more detail here.

Once you are eligible, you will have to go through the steps to enroll in Medicare. If you already receive Social Security retirement benefits or Railroad Retirement Board (RRB) benefits, this enrollment will usually be automatic. We’ll run through the full details about enrollment below.

What are enrollment periods?

When you read about enrolling in Medicare health insurance, you probably hear a lot about enrollment periods. There are several types of enrollment periods, and each one has different rules and conditions. The important thing to understand is that most of the time, you will not be able to enroll in Medicare plans outside of the given enrollment period. In some cases, you may be able to enroll but will face a penalty.

Premium-free Part A

Before you look at the specific enrollment periods, it’s also important to understand how premium-free Part A works. If you or your spouse have paid the Medicare tax for over 40 quarters, you will not have to pay any premiums for Part A, ever. If the Medicare tax was paid for 30-39 quarters, your premium will be $278 per month. For any number of quarters under this, the monthly premium comes to $506 per month.

What is the late enrollment penalty?

The late enrollment penalty for Medicare is fairly serious and important to avoid. If you delay enrollment in Part A and have to pay premiums, then your penalty will be a 10% higher penalty. This is true no matter how long your delay was.

However, delaying for even longer will result in paying for longer. You will pay this 10% fee for double the amount of time you delayed coverage. For example, if you waited two years to enroll in Medicare Part A, you will pay a 10% higher premium for four years. Because these fees are paid each month, they add up and can be significant and expensive. So, you should make it a priority to try to avoid them.

If you receive premium-free Part A, you can just enroll in Part A no matter your situation. You will pay nothing, and have no reason to delay your coverage even if you have an employer health plan.

The late enrollment penalty for the Part B premium is even higher, and you can read about it here.

The Initial Enrollment Period

The Initial Enrollment Period (IEP) is the time when most people enroll in Medicare. This period lasts for seven months. It consists of your birthday month, along with three months prior and three months after. During this period, you can make decisions about your enrollment in Medicare Part A hospital insurance, as well as Medicare Part B, Part C, and Part D prescription drug insurance.

If you already receive Social Security benefits, you won’t have to do anything to enroll during the IEP. You will receive some materials about Medicare in the mail a few months before your 65th birthday notifying you that you are now eligible, and you will automatically enroll and then receive your Medicare card. If you want to defer your coverage until later, or purchase a Medicare Advantage plan, you will have to specifically contact Medicare to do so.

If you are receiving disability benefits, you will be able to begin Medicare coverage on the 25th month of disability. Your IEP will begin three months prior.

When you turn 65, you will also be able to purchase a Medicare Supplement plan, also known as a Medigap plan.

Our Find a Plan tool makes it easy to compare your Medicare plan options. Just enter your zip code to get started.

The Annual Enrollment Period

The Annual Enrollment Period (OEP) lasts from October 15 to December 7 of each year. The basic idea behind the OEP is that it allows you to modify your Medicare plan and have the changes take effect in January of the following year.

During this period, you can change from Original Medicare to Medicare Advantage, or vice versa. If you have a Medicare Advantage plan, you can use the OEP to enroll in Medicare Part A, along with Part B.

In addition to this, you can also add on a Medicare Part D prescription drug plan, or switch your Medicare Advantage health plan to a different plan that includes drug coverage. The OEP is the perfect time to change your plan if you think that another type of coverage is better for you, and it will allow you to enroll in Part A without any penalties if you are switching from a Part C Advantage plan.

The Special Enrollment Period

In addition to these two enrollment periods, you can also enroll in Part A during a Special Enrollment Period or SEP. The SEP is intended to give you a way to change your coverage if you’ve experienced some change that you have no control over. For example, if you have a private Medicare Advantage plan with a limited provider network, and you move to a new area, you will trigger an SEP and be able to change your plan without penalty.

The SEP will vary in length depending on the situation that triggers it. If you already have Original Medicare, moving will not trigger an SEP, since Original Medicare doesn’t have a geographically limited provider network.

If you are working when you turn 65 and want to stay on your employer health plan, and then lose this coverage, you will trigger an SEP. In this case, you will be able to enroll in Medicare Part A for the first time during a Special Enrollment Period, without penalty. We’ll discuss this option in more detail later on.

The General Enrollment Period

The General Enrollment Period (GEP) lasts from January 1 to March 31 of each year. During this time, you can enroll in Part A or Part B of Medicare if you haven’t already enrolled. This period allows people who didn’t initially enroll in Medicare to enroll in Original Medicare.

Switching to Part A from your employer coverage

If you are still working when you become eligible for Medicare, you can delay your enrollment penalty-free. Doing this will allow you to stay with your current private medical insurance plan, which is a great option if you prefer your group health plan over Medicare.

When you lose your coverage or stop working, you will enter a Special Enrollment Period during which you can enroll in Medicare Part A and can also begin your Part B coverage. SEPs also allow you to enroll in a Medicare Advantage plan or a Part D drug plan during this time. This will be the case no matter at what age you lose health coverage based on your current employment.

It’s important to note that this won’t apply to COBRA plans. If you have a COBRA plan and choose to delay your Medicare coverage, you will have to pay a penalty later on.

The main takeaways on Medicare enrollment

For most people, Part A enrollment will be easy and automatic. Nevertheless, understanding how the enrollment process works is essential when it comes to making sure that you don’t pay any late penalties and don’t experience any gaps in coverage.

Understanding enrollment periods is important aside from Part A, since it is relevant for transitioning to Medicare Advantage as well. Even if your Part A enrollment is automatic, understanding the enrollment and eligibility processes will make your experience with Medicare much easier.