A person is automatically enrolled in Part A and Part B if he or she is getting benefits from Social Security or the Railroad Retirement Board (RRB). Coverage starts the first day of the month the person turns 65. (If a person’s birthday is on the first day of the month, coverage will start the first day of the prior month.)
If a person is under 65 and disabled, coverage for Part A and Part B automatically starts after he or she has received disability benefits from Social Security or certain disability benefits from the RRB for 24 months.
If the person has ALS (Amyotrophic Lateral Sclerosis, also called Lou Gehrig’s disease), coverage for Part A and Part B automatically starts the month Social Security disability benefits begin.