If you are turning 65 and receiving Social Security or Railroad Retirement benefits, you may be automatically enrolled. If you are not automatically enrolled, you can enroll by calling Social Security at (800) 772-1213, visit the web site (www.ssa.gov), or apply at your local Social Security office. Apply three months before your 65th birthday. That way, you can be sure that your benefits will start on time.
If you are under 65 and disabled:
You automatically get Part A and Part B after you get disability benefits from Social Security or certain disability benefits from the Railroad Retirement benefits for 24 months.
If you have ALS:
You automatically get Part A and Part B the month your disability benefits begin.
If you’re automatically enrolled, you’ll get your red, white, and blue Medicare card in the mail 3 months before your 65th birthday or your 25th month of disability.