You must be 65 to sign up for Medicare, with limited exceptions for younger people with disabilities or end-stage renal disease

Medicare is a federal health insurance program that begins at age 65 for most people. You become may be able to access on the first day of the month you turn 65, or the first day of the month after your 65th birthday, depending on your birth date. The program has different parts — Part A covers hospital care, Part B covers doctor visits and outpatient services, Part D covers prescription drugs, and Part C (Medicare Advantage) is an alternative way to get Parts A and B through a private insurer.

You do not have to wait until you turn 65 to start the sign-up process. You can sign up during your Initial Enrollment Period, which runs for seven months: three months before the month you turn 65, the month you turn 65, and three months after. If you miss this window, you may face a permanent penalty on your premiums, so timing matters.

There are two exceptions to the age 65 rule. People under 65 with end-stage renal disease (permanent kidney failure requiring dialysis or a transplant) can sign up when ready. People who have received Social Security Disability Insurance (SSDI) for 24 months also become may be able to access at any age, not just 65.

Key Takeaways

  • You become may be able to access for Medicare on the first day of the month you turn 65 or the month after, depending on your exact birth date.
  • Your Initial Enrollment Period lasts seven months — three months before you turn 65, the month of your birthday, and three months after — and missing it can cost you in permanent premium increases.
  • If you are still working at 65 and have health insurance through your employer, you may be able to delay Part B sign-up without penalty, but you must sign up for Part A.
  • People under 65 with end-stage renal disease or who have been on SSDI for 24 months can sign up for Medicare regardless of age.
  • You sign up through Medicare.gov, by phone at 1-800-MEDICARE, or in person at your local Social Security office.

How your birth date determines your exact may be able to access month

Medicare may be able to access is tied to the month you turn 65, not the specific day. If you were born on any day in January, your may be able to access month is January. If you were born on any day in February, your may be able to access month is February. Your coverage begins on the first day of that month.

The only exception is if you were born on the first day of a month. In that case, Medicare coverage begins on the first day of the previous month. For example, if you were born on March 1, your coverage begins March 1. If you were born on March 2 or any later day in March, your coverage begins April 1.

This matters because your Initial Enrollment Period is calculated from your may be able to access month. If your may be able to access month is June, your enrollment period runs from March through September. If you sign up during those seven months, there is no penalty. If you sign up in October or later, you will owe a permanent increase to your Part B premium of 10 percent for each full year you delayed.

What happens if you are still working at 65

If you are still employed and covered by your employer's health plan at 65, you have options. You must still sign up for Part A (hospital insurance) during your Initial Enrollment Period, even if you do not use it yet. Part A has no monthly premium if you or your spouse paid Medicare taxes for at least 10 years, so there is no cost to signing up.

You may be able to delay Part B (doctor and outpatient coverage) without penalty if your employer plan is considered creditable coverage — meaning it is at least as good as Medicare. Your employer's benefits office can tell you whether your plan qualifies. If it does, you can sign up for Part B later without the 10 percent permanent penalty. You have eight months after you leave the job or lose the coverage to sign up for Part B penalty-free.

Do not assume your employer plan is creditable. If you delay Part B and it turns out your plan was not creditable, you will owe the penalty retroactively. Ask your employer's human resources or benefits department in writing before you turn 65.

Signing up during your Initial Enrollment Period

You can sign up for Medicare through three routes: online at Medicare.gov, by phone at 1-800-MEDICARE (1-800-633-4227), or in person at your local Social Security office. Online sign-up is usually the fastest — you can complete it in 15 to 20 minutes if you have your Social Security number and birth certificate information handy.

When you sign up, you will choose which parts of Medicare you want. Most people sign up for Parts A and B together. If you want prescription drug coverage, you can add Part D at the same time, or you can choose a Medicare Advantage plan (Part C) instead, which includes drug coverage. You do not have to decide everything at once — you can add Part D later during the annual enrollment period (October 15 through December 7 each year) without penalty if you do not have other creditable drug coverage.

Your coverage will begin on the first day of your may be able to access month if you sign up by the 15th of that month. If you sign up after the 15th, coverage begins the first day of the following month. For example, if you turn 65 in June and sign up by June 15, coverage begins June 1. If you sign up on June 20, coverage begins July 1.

What happens if you miss your Initial Enrollment Period

If you do not sign up during your seven-month Initial Enrollment Period and you do not have a may have access to reason for the delay, you will face a permanent penalty. For Part B, the penalty is 10 percent of the standard premium amount for each full year you were may be able to access but not signed up. If you delayed for three years, you will pay 30 percent more than the standard premium for the rest of your life.

Part D (prescription drug coverage) has a similar penalty: 1 percent of the national average premium for each month you were may be able to access but not signed up. These penalties do not go away, even if you sign up years later.

There are a few situations where you can sign up late without penalty. If you were still covered by an employer plan when you turned 65, or if you were covered by a spouse's employer plan, you have eight months after that coverage ends to sign up for Part B penalty-free. If you were not a U.S. citizen or permanent resident when you turned 65, you have eight months after you become a permanent resident. If you did not receive notice about Medicare, Social Security may waive the penalty, but you have to request it.

Exceptions: Signing up before 65

Most people cannot sign up for Medicare until 65, but two groups can sign up earlier. If you have end-stage renal disease — meaning your kidneys no longer work and you need dialysis or a transplant — you become may be able to access for Medicare when ready, regardless of age. You can sign up as soon as your doctor determines you have end-stage renal disease, even if you are in your 20s or 30s.

If you have been receiving Social Security Disability Insurance (SSDI) for 24 months, you also become may be able to access for Medicare at any age. The 24 months starts from the month you first began receiving SSDI payments, not from the month you applied. Once you have been on SSDI for two years, you are automatically enrolled in Medicare Part A and Part B. You do not have to sign up — it happens automatically.

If you are on SSDI and approaching your 24-month mark, you will receive a notice from Social Security explaining your Medicare coverage. If you do not want Part B (for example, because you are still covered by an employer plan), you can decline it in writing, but you will still be enrolled in Part A.

Frequently Asked Questions

Can I sign up for Medicare before I turn 65?

Only if you have end-stage renal disease or have been on Social Security Disability Insurance for 24 months. Otherwise, you must wait until your may be able to access month, which is the month you turn 65. You can begin the sign-up process three months before that month.

What if I was born on the first day of the month?

Your Medicare coverage begins on the first day of the month before you turn 65. For example, if you were born on July 1, your coverage begins July 1 of the year you turn 65. Your Initial Enrollment Period runs from April through October.

Do I have to sign up for Part B if I am still working?

You must sign up for Part A during your Initial Enrollment Period, but you may be able to delay Part B if your employer plan is creditable coverage. Ask your employer's benefits office whether your plan qualifies before you turn 65. If it does, you have eight months after you leave the job to sign up for Part B without penalty.

What is the penalty for signing up late?

For Part B, you pay 10 percent more per month for each full year you delayed. For Part D (drug coverage), you pay 1 percent more per month for each month you delayed. These penalties are permanent and do not go away if you sign up later.

Will I be automatically enrolled in Medicare when I turn 65?

No. You must sign up during your Initial Enrollment Period. If you are already receiving Social Security benefits, Medicare will contact you about three months before you turn 65. If you are not yet receiving Social Security, you must contact Medicare yourself at 1-800-MEDICARE or through Medicare.gov.