Medicare Enrollment: How and When to Apply for Medicare

HealthCare Writer

Updated on October 15th, 2021

Reviewed by Diane Omdahl

We aim to help you make informed healthcare decisions. While this post may contain links to lead generation forms, this won’t influence our writing. We follow strict editorial standards to give you the most accurate and unbiased information.

Turning 65 this year? Congratulations! You now qualify for Medicare. But do you need to apply for it or it is automatic? How should you actually sign up? There are several ways to do so, which we discuss below. But first, let’s dive into a quick summary on Medicare.

What Is Medicare?

Medicare is the health insurance program the federal government provides to people age 65 and older. You can, though, get Medicare before age 65 if you have specific disabilities, permanent kidney failure or amyotrophic lateral sclerosis (ALS, or Lou Gehrig’s disease).1

The program helps tens of millions of Americans with the cost of healthcare,2 but it’s important to realize that Medicare doesn’t cover all medical expenses or the cost of most long-term care.

The Centers for Medicare & Medicaid Services (CMS) is in charge of Medicare, but it’s the Social Security Administration that will process your application for Original Medicare (Part A and Part B), provide you with information, and oversee premiums and any penalties.

Medicare Part A is hospital insurance and helps to cover costs like inpatient hospital care, skilled nursing facility care, hospice and home health care. Medicare Part B is medical insurance that helps to pay for the care you get from your doctor and other healthcare providers, medical equipment like wheelchairs and walkers, and preventive services like flu and pneumonia vaccinations, and annual wellness visits.

Part A is usually premium-free if you or your spouse have paid Medicare taxes for at least 10 years. Part B, though, is optional and requires a monthly premium payment.

Do You Need to Apply for Medicare?

Most people do need to apply for Medicare. But if you reach age 65 and you’re already receiving retirement benefits from Social Security or the Railroad Retirement Board, you’ll be signed up for Medicare Part A and Part B automatically.

And if you aren’t receiving retirement benefits and you don’t have health coverage through an employer, you will need to apply for Medicare as you approach age 65. If you need to apply, Medicare gives you several options.

How Do You Apply for Medicare?

You can sign up for Medicare online, by phone or in-person at a Social Security office once you’re nearing age 65 if you’re a U.S. citizen or have been a legal resident for at least five years.

How Long Does It Take to Sign Up?

That depends on the method you choose. It can take as little as 10 minutes to sign up online, a month or more by phone or, if you prefer to sign up in person, it will depend on how long it takes to get an appointment.

Considering a Medicare Advantage or Medicare Supplement Plan?

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How Do You Apply Online?

Start by opening a My Social Security account at, following these instructions.

Part of the process will include verifying your identity. So you may need your:3

  • Security number.
  • Valid U.S. mailing address.
  • Email address.
  • Date and place of birth.
  • Permanent Resident Card if you aren’t a U.S. citizen.
  • W-2 and tax forms.
  • Medicaid number, if applicable, with start and end dates.
  • Start and end dates for group health insurance through your (or your spouse’s) employer.
  • Start and end dates of employment with the employer providing your group health plan.

Once your account is set up, you can start the Medicare application process here. It’s unlikely that you’ll need to sign anything physically.

When you’re finished applying online, you’ll get a confirmation number. Keep it handy and use it to check the status of your application through your My Social Security account. Social Security will let you know if more information is needed.4

How Do You Apply by Phone?

Call (800) 772-1213 or TTY (800) 325-0778 between 7 a.m. and 7 p.m. from Monday through Friday.5 Keep in mind that this process takes longer because forms have to be mailed to you, which you then complete and send back. At peak times, applying for Medicare by phone could take a month or more.

If you worked at a railroad, you can enroll in Medicare by calling the Railroad Retirement Board at (877) 772-5772 or TTY (312) 751-4701, 9AM – 3:30PM, Monday – Friday.

How Do You Apply in Person?

Start by finding the Social Security office closest to you. (You can do this by entering your ZIP code in the Social Security Office Locator). Not all offices offer appointments, but if yours does, you can make an appointment by calling (800) 772-1213 or TTY (800) 325-0778. Once you get an appointment, processing your Medicare application should proceed quickly.

When Can You Enroll in Medicare?

You can apply for Medicare during three distinct enrollment periods: your Initial Enrollment Period, the General Enrollment Period and a Special Enrollment Period when you’re getting off your employer’s health coverage. 

Medicare Enrollment Dates

January 1 – March 31General Enrollment PeriodSign up for Medicare Part A or B (Original Medicare) if you didn’t sign up when first eligible.
January 1 – March 31Medicare Advantage Open Enrollment PeriodChange or leave your Medicare Advantage plan.
January 1 – December 31 Medicare Supplement Insurance (Medigap) EnrollmentChange plans although your insurer may check your medical history to determine eligibility (medical underwriting).
October 15 – December 7Annual Election Period (Open Enrollment Period)Change from Original Medicare to Medicare Advantage, or vice versa; change Medicare Advantage plans; join, change or leave Medicare Part D prescription drug coverage.
December 8 – November 305-Star Special Enrollment PeriodChange to a 5-star Medicare Advantage or Part D prescription drug plan.

When Is the Earliest You Can Sign Up?

You’re first eligible for Medicare starting three months before you turn 65. That kicks off what’s known as your Initial Enrollment Period. (You can defer enrollment penalty-free if you have employer-provided health coverage; see the section below on Special Enrollment Periods.)

The Initial Enrollment Period covers seven months: the three months before your 65th birth month, the month of your 65th birthday and the three months following your 65th birth month. For example, let’s say your birthday is sometime in May. The three months before are February, March and April, and the three months following are June, July and August.

Keep in mind that the date you apply for Medicare will affect the start date of your coverage. To receive Medicare Part A (hospital insurance) and Medicare Part B (medical insurance) beginning the first day of the month you turn 65, you must sign up during the three months before your 65th birth month. If you wait to sign up during your birth month or the next three months, your start date will be delayed by one, two or three months.

If your birthday is on the first day of your birth month, Part A and Part B will start the first day of the prior month. So, if, say, your birthday is September 1, your benefits will begin on August 1.

When Can You Sign Up If You Missed the Initial Enrollment Period?

If you didn’t sign up when you were first eligible and you don’t have current healthcare coverage elsewhere (as with your employer), you’ll have to wait for the next General Enrollment Period which runs each year from January 1 through March 31.

Your coverage will then begin in July of that year, and you may have to pay a late enrollment penalty on your Medicare Part B premium for as long as you have Part B coverage. Your premium will go up by 10% for every 12-month period you weren’t enrolled.

When Can You Sign Up Outside of the Initial and General Enrollment Periods?

You could qualify for a Special Enrollment Period (SEP) and avoid the penalty for enrolling late. SEPs are typically granted if you or your spouse are still working when you turn 65 and you have group health insurance through an employer or union.

In that case, you’re allowed to enroll in Part B at any time you have qualified group health coverage and you’ve turned 65. Once you no longer have coverage, you can enroll during the eight-month SEP period that starts the month after you lose the job or the coverage, whichever comes first.

When Should You Apply for Medicare If You Have Employer Health Coverage?

Most people should sign up for Medicare Part A when they’re first eligible because it rarely costs anything. But some people delay enrolling in Part B because they don’t want to pay the monthly premium. The decision usually depends on the type of health coverage you already have.

You can put off enrolling in Part B at age 65 if you have group health coverage through your or your spouse’s job and the employer has at least 20 employees.6 You’ll be able to enroll with no penalty during the Special Enrollment Period that follows the end of your employer’s insurance. You can also choose to enroll in Part B while still insured and pay the premium.

If your employer has fewer than 20 employees, you should apply for Part A and Part B as soon as you’re eligible.7

Be sure to talk to your employer’s benefits administrator about how signing up for Medicare will affect your coverage or Health Savings Account (HSA).8 You cannot contribute to an HSA if you have Medicare Part A. Your administrator can help you time the beginning and end of your coverage through work and your new health insurance so there’s no gap in your coverage.

When your group coverage is ending, you’ll need to complete documentation and submit it to your Social Security office. If you have questions, ask Social Security.

What Other Times Can You Sign Up?

You may also become eligible for Medicare for other reasons. If you’re eligible due to a disability, you qualify after you’ve received Social Security disability or certain Railroad Retirement Board disability benefits for 24 months.

If you have end-stage renal disease (ESRD), you’re eligible in the fourth month of dialysis treatment, possibly earlier.9 And if you have ALS, you qualify the same month your disability benefits begin.10

What Are the Two Enrollment Methods?

Automatic Enrollment

If you’re already getting Social Security or Railroad Retirement Board benefits, you don’t need to enroll in Medicare. You’ll automatically get Original Medicare (Part A and Part B) as of the first day of the month you turn 65.

Those who are automatically enrolled will receive a “Welcome to Medicare” packet, which will include your Medicare card, three months before turning 65.

Considering a Medicare Advantage or Medicare Supplement Plan?

Review options now.

Considering a Medicare Advantage or Medicare Supplement Plan?

Review options now.

The packet also includes information to help you decide:11 

●    If you want to keep Part B.

●    If you do keep Part B, how you want to receive your Medicare coverage.

●    If you want Medicare prescription drug coverage, Part D.

●    If you want a Medicare Supplement Insurance policy.

If you decide you don’t want Part B, you must return the Medicare card. If you keep the card, you keep Part B coverage and you will be charged the monthly premium.

 Note that if you live in Puerto Rico, you will only receive Medicare Part A automatically. You need to call Social Security at (800) 772-1213 or TTY (800) 325-0778 to apply for Part B if you want it.

Manual Enrollment

You will not get Medicare automatically if you are not already receiving benefits from Social Security or the Railroad Retirement Board, even if you’re close to age 65. You need to apply for Part A and Part B if you want them using one of the methods mentioned here, even if you’re eligible for premium-free Part A.

The government expects you to know when to enroll. Be sure to apply for Part B during your Initial Enrollment Period unless you have current employment-based insurance coverage elsewhere. (COBRA and retiree benefits don’t count.) If you don’t apply and sign up later, you will have to pay a Part B late enrollment penalty for as long as you’re enrolled in Part B.

When Will You Get Your Medicare Card?

medicare card

Your Medicare card will arrive in your “Welcome to Medicare” packet. Once you’ve submitted your application, the packet will arrive about two weeks after you’ve been approved.12

If you’re already receiving benefits from Social Security or the Railroad Retirement Board, expect the packet to arrive about three months before you turn 65.

What Are Important Medicare Decisions??

Applying for Medicare Parts A and B is the first step. Other decisions related to Original Medicare can be made in the same timeframe: 

Next Steps

Once you’ve completed your Medicare application, remember to look into the two other time-critical decisions: enrolling in Medicare Part D for drug coverage and buying Medicare Supplement (Medigap policy) to Original Medicare.

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  1. Social Security Administration. “Medicare Benefits.” (accessed May 4, 2020).

  2. Centers for Medicare & Medicaid Services. “MDCR ENROLL AB 1.” (accessed May 4, 2020).

  3. Social Security Administration. “Checklist for Online Medicare, Retirement, & Spouses Applications.” (accessed May 4, 2020).

  4. Social Security Administration. “Apply Online for Medicare – Even If You Are Not Ready to Retire.” (Accessed June 18, 2020).

  5. Social Security Administration. “Other Ways To Apply For Benefits.” (accessed May 4, 2020).

  6. U.S. Government Website for Medicare. “Should I get Parts A & B?” (accessed May 4, 2020).

  7. Should I get Parts A & B?

  8. Medicare Benefits.”


  9. Centers for Medicare & Medicaid Services. “End-Stage Renal Disease (ESRD).” (accessed May 4, 2020).

  10. U.S. Government Website for Medicare. “Getting Medicare if you have a disability.” (accessed May 4, 2020).

  11. U.S. Government Website for Medicare. “Enrolling in Medicare Part A & Part B.” (accessed May 4, 2020).


  12. U.S. Government Website for Medicare. “Get started with Medicare.” (accessed May 4, 2020).