How Do I Sign Up For Medicare B? 
You can sign up for Medicare Part B in 3 ways : 1 -RRB- You can go to Medicare.gov and fill out the online registration . You will be directed to a Social Security website with a form to fill in and submit electronically . 2 -RRB- If you already have Part A , you can call 1-800-772-1213 . 3 -RRB- You can contact your local Social Security Office . 