Some people are automatically enrolled in Original Medicare (Part A and Part B) and other people have to sign up for it. In most cases, if you’re turning 65 and will be getting benefits from Social Security or the Railroad Retirement Board (RBB) at least 4 months before you turn 65, you will automatically get Medicare Part A and Part B starting the first day of the month you turn 65. If you’re under 65 and have a disability, you’ll automatically get Medicare Part A and Part B after you get disability benefits from Social Security or certain disability benefits from the RRB for 24 months. You don’t need to sign up if you automatically get Medicare Part A and Part B. You will get your Medicare card in the mail three months before your 65th birthday or 25th month of disability.