Medicare is health insurance for people aged 65 or older. However, some people may be eligible to get Medicare earlier if they have a disability, End-Stage Renal Disease (ESRD), or ALS (also called Lou Gehrig’s disease) . If you start getting retirement or disability benefits from Social Security before you turn 65, you may be automatically enrolled in Medicare Part A and Part B. Generally, youre first eligible to sign up for Part A and Part B starting 3 months before you turn 65 and ending 3 months after the month you turn 65. If you don’t get Medicare automatically, you can sign up online, call Social Security, contact your local Social Security office, or call the Railroad Retirement Board if you or your spouse worked for a railroad. If you don’t sign up for Medicare when you’re first eligible, you’ll have to wait until the General Enrollment Period (January 1-March 31 each year) to sign up, and you may have to pay a late enrollment penalty.