For most Americans, Medicare starts at age 65. Coverage at age 65 can begin as early as the first day of your birthday month.

Keep reading to learn more about enrollment, when coverage starts, and early eligibility requirements.

If you’re eligible to receive benefits at age 65, your initial Medicare enrollment period:

  • begins three months prior to your 65th birthday
  • includes the month you turn age 65
  • ends three months after that birthday

If you don’t enroll in Medicare Part B during your initial enrollment period, there is a general enrollment period every year from January 1 through March 31.

By signing up for Medicare Part A (hospital insurance) and Medicare Part B (medical insurance) during your initial enrollment period’s first 3 months, your coverage will start on the first day of your birthday month.

  • Example: If your 65th birthday is May 7, 2020, and you sign up for Medicare between February and April of 2020, your coverage will begin on May 1, 2020.

If your birthday falls on the first day of the month, your coverage starts on the first day of the month before your birthday month.

  • Example: If your 65th birthday is October 1, 2020, and you sign up for Medicare between June and August of 2020, your coverage will begin on September 1, 2020.

Signing up for Part A and/or Part B during the last 4 months of your initial enrollment:

  • If you sign up in the month you turn 65, your coverage will start 1 month after you sign up.
  • If you sign up in the month after you turn 65, your coverage will start 2 months after you sign up.
  • If you sign up 2 months after you turn 65, your coverage will start 3 months after you sign up.
  • If you sign up 3 months after you turn 65, your coverage will start 3 months after you sign up.

If you missed your initial enrollment period, you can sign up for Part A and/or Part B during the January 1 through March 31 general enrollment period. In this case, your coverage will start on July 1.

Signing up for Part B after your initial enrollment period may affect your monthly premiums

It’s important to note that if you don’t sign up for Part B during your initial enrollment period, you potentially risk paying late enrollment penalties. These penalties may affect your monthly costs (premiums). Click here for more information about late enrollment penalties.

In some cases, you can become eligible for Medicare before you’re 65. You can qualify for Medicare at a younger age if:

  • You’ve received Social Security or Railroad Retirement disability payments for 24 months. This triggers automatic enrollment.
  • You have amyotrophic lateral sclerosis (also known as ALS or Lou Gehrig’s disease). You will be automatically enrolled in Medicare Part A and B the first month your Social Security and Railroad Retirement disability benefits begin.
  • You have end stage renal disease (also known as ESRD or end-stage kidney disease). Your Medicare coverage starts on the 4th month of dialysis treatments. If you participate in a home dialysis training program, your coverage could potentially start on the first month of dialysis.

The date your Medicare coverage begins depends on:

  • when you sign up during your initial enrollment period
  • if you sign up during the general enrollment period

Although most Americans start their Medicare coverage on or near their 65th birthdays, there are some circumstances that could make Medicare available to them at an earlier age, such as:

  • 24 months of Social Security or Railroad Retirement disability payments
  • ALS (amyotrophic lateral sclerosis)
  • ESRD (end stage renal disease)