When it is time to apply for Medicare, you have a number of options, although all of them are through the Social Security Administration (SSA). You also have several decisions to make regarding your Medicare coverage. This post explains the various Medicare enrollment periods and your Medicare plan options.

How to sign up for Medicare

Although the Centers for Medicare & Medicaid Services (CMS) manage the Medicare program, most people sign up for Medicare through Social Security. You have three options:

• The Social Security website (SSA.gov)
• Calling toll-free at 1-800-772-1213 (TTY 1-800-325-0778) from 7 AM to 7 PM Monday through Friday
• Signing up in person at your local Social Security office

If you choose to enroll in person, please locate your local SSA office here. You also need to call ahead to schedule an appointment.

The only people who do not enroll in Medicare through Social Security are former railroad workers. If you retired from the railroad, contact the RRB (Railroad Retirement Board) toll-free at 1-877-772-5772 (TTY 1-312-751-4701). An RRB representative can help you Monday through Friday from 9 AM to 3:30 PM.

Can I sign up for Medicare online?

Yes, you may sign up for Medicare online here. In fact, it's the fastest, easiest way to do it. The whole process takes less than 10 minutes and the application is available 24 hours a day, 7 days a week. In other words, you do not have to schedule an appointment or limit yourself to standard business hours when you apply for Medicare online.

Most people only need their birthdate and place of birth to complete the application. However, you may also need to supply the following information, if you have Medicaid, are a permanent resident, or have other health insurance.

• Medicaid number
• Permanent Resident Card number
• Group plan information
• Employment information if your group plan is through an employer

Before completing the online application, make sure Social Security has up-to-date information by creating a my Social Security account (use the above SSA link to create your account). If any of your information does not match what Social Security has on record, you may not be able to complete your application online.

Is Medicare enrollment automatic?

Not everyone needs to sign up for Medicare. If you live in the United States and began receiving Social Security or RRB benefits at least 4 months before your 65th birthday, you are automatically enrolled in Medicare Parts A and B (also known as Original Medicare). Puerto Rico residents are automatically enrolled in Part A but must sign up for Medicare Part B.

Enrollment is also automatic if you collect disability benefits from either Social Security or the Railroad Retirement Board. Those who are younger than 65 qualify at their 25th month of disability benefits.

If you have amyotrophic lateral sclerosis (ALS,  also known as Lou Gehrig's disease), you are automatically enrolled in Medicare the very first month you collect disability benefits.

Patients who receive a diagnosis of end-stage renal disease (ESRD) are not automatically enrolled, but they are eligible for Medicare. To receive full benefits for services like dialysis and kidney transplant, you must enroll in Medicare Part B as well as Part A.

What if you don't want Medicare Part B?

Not everyone who qualifies for automatic enrollment wants Medicare Part B – usually because they have health insurance through their spouse's employer. If this describes you and you received your new Medicare card with your Welcome to Medicare packet, sending the card back disenrolls you from Part B. Just follow the instructions on the back of your red, white, and blue card.

Before you reject Part B coverage, talk to your benefits administrator. Your current coverage may change once you become eligible for Medicare.

For example, if your coverage is a group plan sponsored by a small company (one employing fewer than 20 people), you need to keep your Part B insurance. This is because Medicare is considered the primary insurer, meaning your insurance company only pays after Medicare pays its share.

If you signed up for Medicare and want to drop your Part B coverage, you need to contact Social Security. Follow their instructions to submit your request

When can you enroll in Medicare?

If you do not collect Social Security benefits, you have to sign up for Medicare. If you are new to Medicare, you have two options. The first is your Initial Enrollment Period (IEP). If you miss that, you can enroll during the Medicare General Enrollment Period (GEP).

When is your Initial Enrollment Period?

You first become eligible to apply for Medicare 3 months before you turn 65. This is known as your Initial Enrollment Period.

Your IEP begins 3 months before the month you turn 65 and lasts through the 3 months following your birth month. So, if you turn 65 on May 20, your IEP begins on February 1 and ends on August 31.

Signing up for Medicare during the 3-month period before your 65th birthday ensures you enjoy coverage the month you turn 65. If you sign up any time after that, your coverage is delayed for 1 to 3 months, depending on when you enroll.

If you do not receive retirement benefits at least 4 months before you turn 65, you must sign up for Medicare during your Initial Enrollment Period. Failure to do so may result in lifelong late enrollment penalties if you do not qualify for a Special Enrollment Period (SEP). We cover SEPs in more detail below.

You may sign up for Medicare even if you do not wish to begin receiving Social Security benefits. Just choose "Apply for Medicare Only" on the Social Security website. You may always apply for retirement benefits later (assuming you qualify).

When is the Medicare General Enrollment Period?

The Medicare General Enrollment Period occurs every year from January 1 through March 31. You may enroll in Medicare during this time if you missed your Initial Enrollment Period. Your Medicare coverage will begin the month after you sign up.

Depending on how long you delayed Medicare enrollment, you may owe late penalties.

If your IEP includes January, February, or March, signing up for Medicare during this time still counts as your Initial Enrollment Period.

What is the Medicare Part A Late Enrollment Penalty?

You qualify for premium-free Part A if you or your spouse worked and paid Medicare taxes for 40 quarters (approximately 10 years). The Medicare Part A premium for those who did not earn the 40 credits is $505 in 2024.

The Medicare Part A late penalty is 10% of your monthly premium for twice the number of years you delayed enrollment. It works like this:

• Delaying enrollment for 12 full months = 2 years paying the penalty
• Delaying enrollment for 24 full months = 4 years paying the penalty

And so on. You only accrue this penalty any time a full 12 months passes without being enrolled in Medicare Part A.

What is the Medicare Part B Late Enrollment Penalty?

The Medicare Part B late enrollment penalty is 10% for every 12-month period you could have had Part B but did not. It works like this:

• Delayed enrollment for 12 months = 10% penalty
• Delaying enrollment for 24 months = 20% penalty
• Delaying enrollment for 36 months = 30% penalty

And so on. The standard Medicare Part B premium is $174.40 in 2024. If your household income exceeds $103,000 (filing single) or $206,000 (married filing jointly), your Part B premium may be higher.

Unlike the Part A penalty, you pay this late fee for the entire time you have Medicare. That is why it is so important to complete your Medicare application during your Initial Enrollment Period if you do not qualify for an SEP.

The Medicare Special Enrollment Period

If you meet certain criteria, you may qualify for a Special Enrollment Period. When you first become eligible for Medicare, this typically means having creditable coverage through an employer- or union-sponsored group health plan. For convenience, we use "you" here, but the following applies whether it is your job or your spouse's.

There are two main criteria for employer coverage to qualify you for an SEP.

• You must be actively employed
• Your employer must employ at least 20 people

If both of those criteria do not apply, you will not qualify for a Special Enrollment Period.

"Actively employed" means that you are still working for your employer, not retired. Retiree insurance, COBRA, and similar plans are considered secondary to Medicare. Failure complete the Social Security Medicare application during your IEP starts the clock ticking on those late enrollment penalties.

How long does the Special Enrollment Period last?

There are dozens of ways to qualify for a Special Enrollment Period and each one has its own timeline. You can find the full list here on Medicare.gov.

However, in this post, we focus on people who are newly eligible for Medicare. If you have employer coverage when you turn 65 and it meets the criteria described above, you may delay Medicare enrollment without incurring a late penalty. You just have to make sure you sign up for Medicare within 8 months after your employer-sponsored health plan ends.

Again, please note that COBRA coverage is always secondary to Medicare since, by definition, COBRA means you are not actively employed. You may keep your COBRA coverage, but it will not exempt you from paying late penalties.

When can you enroll in a Medicare Advantage plan?

You may choose to enroll in a Medicare Advantage (MA) plan when you first become eligible for Medicare, during your IEP.

Also known as Medicare Part C, Advantage plans must provide the same level of coverage as Original Medicare. Over 90% also provide additional benefits. The most common extras are:

• Prescription drug coverage (known as an MA-PD plan)
• Routine vision care
• Routine dental care
• Hearing aids
• Health and fitness plans

To enroll in a Medicare Advantage plan, you must first sign up for Parts A and B.

Medicare Advantage plans are sold by private insurance companies, so benefits and prices vary according to the plan and provider.

Other opportunities to enroll in a Medicare Advantage plan

In addition to your Initial Enrollment Period, you may also enroll in an Advantage plan during the Medicare Annual Enrollment Period (AEP) and Medicare Advantage Open Enrollment Period (OEP).

Annual Enrollment occurs every year from October 15 through December 7. You AEP options include:

• Leaving Original Medicare for a Medicare Advantage plan
• Switching from one MA plan to another
• Leaving an MA plan to return to Original Medicare
• Buying a new Part D prescription drug plan (PDP)

Anyone who is currently enrolled in Medicare may participate in Annual Enrollment.

The Medicare Advantage Open Enrollment Period occurs every year from January 1 through March 31. Changes you can make during OEP include:

• Switching from one Advantage plan to another
• Leaving your MA plan to return to Original Medicare
• Purchasing a new Part D plan if the changes you make result in you losing prescription drug coverage

To participate, you must already be enrolled in an Advantage plan.

The only other time you may enroll in or leave a Medicare Advantage plan is if you qualify for a Special Enrollment Period.

When can you enroll in a Medicare Part D Prescription Drug plan?

Original Medicare does not include coverage for prescription medications. To get this coverage, you must enroll in either a Medicare Part D prescription drug plan or an Advantage plan that includes drug coverage. Even if you're automatically enrolled in Medicare when you turn 65, you must sign up for a Part D plan.

You may enroll in a Part D plan during your Initial Enrollment Period or when you first sign up for Medicare after you leave an employer health plan. If you're currently enrolled in Medicare, you may also sign up for a prescription drug plan during the Annual Enrollment Period from October 15 to December 7.

Like Medicare Part C, Medicare Part D plans are offered by private insurance companies. And again, prices and coverage vary according to the plan and provider. Use our Find a Plan tool to start comparing Medicare plan options in your area.

What happens if you don't have Medicare Part D?

If you do not have creditable drug coverage elsewhere, you must have a Medicare Part D plan if you want to avoid paying late fees. Any time you go 63 days or more without prescription drug coverage and do not qualify for an SEP, you start accruing late fees.

The Medicare Part D late penalty is based on the national base beneficiary premium, which changes every year. The number of months you go without creditable coverage is also part of the calculation.

In 2024, the national base beneficiary premium is $34.70. You pay 1% of this amount for every month you go without coverage. That total is then rounded to the nearest dime. The example below assumes you go 10 months without a Part D plan.

$34.70 x 10% = 3.47, rounded to the nearest dime = $3.50

This amount is added to your monthly Part D premium for the entire time you have Medicare.

Creditable coverage is that which is considered equal to Medicare in terms of price and coverage. Your plan should send you notification that your coverage is creditable when you first enroll and then every year that you have the plan. Save these notices, as they provide the proof of creditable coverage that you need when you do eventually buy a Part D plan.

When can you enroll in a Medicare Supplement Insurance plan?

If you have Original Medicare, you may choose to add a Medicare Supplement plan to help pay some of your out-of-pocket costs. More commonly referred to as Medigap, private insurance companies sell Supplement plans.

Although the plans are provided by private insurers, Medicare requires them to be standardized. That means that every Medigap Plan A (or Plan B, C, etc.) provides the same benefits, no matter where you buy it. However, costs vary according to the provider you choose.

We always recommend enrolling in a Medicare Supplement plan during you Medigap Open Enrollment Period. This begins the first month you are both aged 65 or older and enrolled in Medicare Part B.

Your Medigap OEP is one of the few times you have guaranteed issue rights, meaning you cannot be denied a Supplement plan or charged a higher rate for it. Outside of your Medigap Open Enrollment Period, your application goes through the medical underwriting process.

Medical underwriting involves answering a variety of health-related questions. This may include:

• Age
• Weight
• Tobacco use history
• Whether you have any chronic conditions, such as high blood pressure or diabetes
• Personal and family medical history

The insurance company may refuse to sell you a Medigap policy based on your answers to any these questions.

You can compare Medigap plan options in your area with our Find a Plan tool. Just enter your location to begin reviewing Medicare plans in your area.

Additional resources

• ClearMatch Medicare: Find a Medicare Plan
• SSA: Social Security Office Locator