又问8老师：SSN not for employment

岳父30年前持J-1做访问学者期间获老板赏识并提供额外资助，获得SSN (not valid for employment). SSN被面说：Contact any social Security office immediately if you: ....4) are 62 or older-to ask about retirement check. 5) are within 2 or 3 months of age 65, even if you don't plan to retire-to sign up for medicare. 那是些福利吗？他只工作不足两年。