Medicare Part B Explained

Medicare Part B helps cover medically necessary services like doctors’ services, outpatient care, home health services, and other medical services. Part B also covers some preventive services. You can find out if you have Part B by looking at your Medicare card.

How Do You Get Medicare Part B?

  • If you get benefits from Social Security or the Railroad Retirement Board (RRB), in most cases you will automatically get Part B starting the first day of the month you turn 65. If your birthday is on the first day of the month, your Part B will start the first day of the prior month.

  • If you are under 65 and disabled, you will automatically get Part B after you get disability benefits from Social Security or certain disability benefits from the RRB for 24 months. You will get your Medicare card in the mail about three months before your 65th birthday or your 25th month of disability.

  • If you do not want Part B, follow the instructions that come with the card, and send the card back. If you keep the card, you keep Part B and will pay Part B premiums.

  • If you have ALS (Amyotrophic Lateral Sclerosis, also called Lou Gehrig’s disease), you automatically get Part B the month your disability benefits begin.

When Can You Sign up for Part B?

If you didn’t sign up for Part B when you first became eligible, you may be able to sign up during one of these times:

  • General Enrollment Period — Between January 1–March 31 each year. Your coverage will begin on July 1. You may have to pay a late enrollment penalty.

  • Special Enrollment Period — If you wait to sign up for Part B because you or your spouse is currently working, and you are covered by a group health plan based on that work, or if you are disabled and you or a family member is working, and you are covered by a group health plan based on that work. You can sign up for Part B anytime while you have group health plan coverage based on current employment or during the 8-month period that begins the month after the employment ends, or the group health plan coverage ends, whichever happens first. If you have COBRA coverage, you must enroll during the 8-month period that begins the month after the employment ends. This Special Enrollment Period doesn’t apply to people with End-Stage Renal Disease (ESRD).

  • Special Enrollment Period for International Volunteers — If you waited to sign up for Part B because you had health insurance while volunteering outside of the U.S. for a tax-exempt organization for at least a year. You can sign up during the 6-month period that begins the first month that any one of the following happens:

    • You are no longer volunteering outside the U.S.

    • The sponsoring organization is no longer tax-exempt.

    • You no longer have health insurance coverage outside the U.S.

If you have Medicare because of End-Stage Renal Disease (ESRD), you can sign up for Part B when you sign up for Part A. If you delay signing up for Part B, you can only get it during the general enrollment period, and you may have to pay a late enrollment penalty.

If you live in Puerto Rico, and you want Part B, you will need to sign up for it. Contact your local Social Security office for more information.

If you aren’t getting Social Security or RRB benefits, and you want to get Part B, you will need to sign up for Part B during your initial enrollment period (the 7-month period that begins three months before the month you turn age 65, includes the month you turn age 65, and ends three months after the month you turn age 65).

Important Note:
If you do not sign up for Part B when you are first eligible, you may have to pay a late enrollment penalty for as long as you have Medicare. Your monthly premium for Part B may go up 10% for each full 12-month period that you could have had Part B, but didn’t sign up for it. Usually, you don’t pay a late enrollment penalty if you sign up for Part B during a special enrollment period.