When you first start dealing with Medicare, it can be quite confusing. There are multiple parts, different types of coverage, and they all function somewhat independently. Thankfully, enrolling in Medicare, and most of the process of beginning coverage is a fairly simple process.

Filing for Medicare will vary depending on your specific situation. It can range from completely automatic to a more complex, time-dependent process that you do on your own. We’ll run through the most common situations you’re likely to face, so you can know how to proceed when that time comes.

Filing at 65: The Initial Enrollment Period

Most people's Medicare eligibility begins when they turn 65. Enrolling in Medicare at 65 is most often done during what’s known as the Initial Enrollment Period.

This period lasts for 7 months. It begins three months before the month of your 65th birthday, contains that month as well, and three months after. So, if your birthday is in August, your Initial Enrollment Period will last from May and go through November. This will be the same no matter when in August your birthday is.

You will receive a package in the mail from CMS (Centers for Medicare & Medicaid Services) with information and your Medicare card a few months prior to your birthday month.

During the Initial Enrollment Period, you can begin your enrollment in Medicare. Although you may begin the process early on in the period, your coverage will begin during your 65th birthday month. If you do decide to enroll in Medicare for Part A hospital insurance and Part B coverage, make sure to cease your other insurance coverage, unless you want to keep both forms of insurance. If you do have a private plan, Medicare will function as the secondary payer.

If You Already Receive Social Security Benefits

If you receive benefits from the Social Security Administration (SSA) already, then your enrollment will be even easier. In this case, your enrollment will be fully automatic.

You will be enrolled in Medicare Part A and Medicare Part B automatically, and your monthly premiums will be taken out of your Social Security benefits payment each month. This is by far the easiest way to enroll in Medicare.

If You Receive Railroad Retirement Benefits

The situation for enrolling is the same for those who receive benefits from the Railroad Retirement Board. Enrollment should be fully automatic and premium payments will be tied to your benefit payment each month.

You can contact the Railroad Retirement Board at 1-877-772-5772 (TTY users 1-312-751-4701) for more information about enrolling.

Deferring Coverage

Some people who become eligible may have good reasons for not enrolling in Medicare. If this is the case for you, you can defer your coverage.

Without a good reason for deferring, you may face a late enrollment penalty which can significantly raise your Part A and Part B premiums. If you already have a group health plan as part of your employer-based coverage, then you will be able to keep that coverage until you lose it, and won't face a penalty when you enroll in Medicare later on.

However, if you have COBRA health insurance, then you will still have to pay the late penalty if you enroll in Medicare after your Initial Enrollment Period.

Open Enrollment: Changing Your Coverage

Open Enrollment is important to understand whether or not you enrolled during your Initial Enrollment Period. Open Enrollment lasts from October 15th to December 7th of each year and allows you to do a few useful things.

First, you will be able to enroll in Medicare each year during Open Enrollment, if you didn’t enroll during your Initial Enrollment Period. Your coverage will begin on January 1st. If you didn’t enroll during your Initial Enrollment Period without a sufficient reason, then you may have to pay a late enrollment penalty. These penalties can be severe and will add up for both Part A and Part B depending on how long you waited to enroll.

Second, Open Enrollment also allows you to change your coverage. This is useful if you want to switch from Original Medicare to Medicare Advantage, or vice versa. You can also add a Part D prescription drug plan during this time. Basically, any type of change you may want to make to your coverage is available to you during open enrollment, and you won’t face any penalties for changing your coverage during this time.

General Enrollment: Another Opportunity

The General Enrollment period isn’t used quite as often as Open Enrollment, but it’s a very useful period to be aware of. This period lasts from January to March of each year, and coverage will begin on July 1st.

General Enrollment is especially useful if you miss your Initial Enrollment Period but your birthday is later in the year. Rather than waiting until October to get Medicare health coverage, you can enroll in January. This period functions in a very similar way to Open Enrollment, and just gives you another opportunity to enroll. If you have a late enrollment penalty, it will still apply if you enroll during the General Enrollment Period.

Special Enrollment for Special Circumstances

The Special Enrollment Period is in some ways the simplest and most complex of all the enrollment periods. This period has no fixed length and can vary from person to person, depending on the circumstances at hand.

The idea behind the Special Enrollment Period is that it can allow people who experience some circumstances outside of their control to enroll in Medicare without penalty. This can be very useful in a number of situations.

For example, if you defer Medicare enrollment because you’re keeping your employer-based insurance, then you will trigger a Special Enrollment Period when you lose your employment. This can also happen if you have a Medicare Advantage plan and move outside of the provider network service area. There are a number of other situations, and some have enrollment periods of differing lengths.

Special Enrollment Periods are very important to understand if you’re going to be enrolling in Medicare. Even if you don’t think you will have to use one, they are often used for unpredictable events. As such, make sure you at least familiarize yourself with the basics.

Enrollment in Part D: Medicare Prescription Drug Coverage

Medicare Part D refers to prescription drug coverage, which isn’t covered by Original Medicare (Parts A and B). Part D is offered by private insurance companies, meaning the coverage and cost can vary.

Part D plans will follow the same rules as Original Medicare when it comes to enrollment. If your Part D plan has a specific service area for coverage and you move to a new location, you will be able to get a new plan under a Special Enrollment Period.

Enrollment in Medicare Advantage

Medicare Advantage functions as a way to get your Medicare benefits through a private insurance company. Also known as Medicare Part C, Medicare Advantage runs parallel to Original Medicare, meaning that you can’t have both.

There are distinct pros and cons to Medicare Advantage medical insurance, and ultimately it will be up to you to decide which option you want to take.

As far as enrollment goes, you can expect the same enrollment guidelines as for Original Medicare. You can enroll in Medicare Advantage during any enrollment period, and you can also switch from Original Medicare to Medicare Advantage during that time.

One small complication to note is that some Part C plans also have prescription drug coverage. In this case, you can’t have a Part D prescription drug plan at the same time as a Medicare Advantage plan that has prescription drug coverage. If you have Original Medicare and a Part D plan, then you will lose your Part D plan if you switch to a Part C plan that has drug coverage.

Final Thoughts on Filing for Medicare

If you’re entering a stage of life at which you become eligible for Medicare, then understanding how to enroll is key. For most people, this process will be easy, but nevertheless, it’s important to keep a few key things in mind.

Make sure you remember the timing of all of the enrollment periods, because even if you don’t need them now, you may need them in the future. Not understanding enrollment periods can lead to a possible gap in Medicare coverage.

And, make sure you understand how your payments will be processed, so you never miss a payment by thinking that your payments are automatic if they aren’t.