Medicare Part A and Part B
To check your Medicare Part A and Part B effective date, look at the lower right corner of your Medicare card. The effective date is also stated on the letter that you received from Social Security or the Railroad Retirement Board.
If neither of these items are available, call the Social Security Administration Monday through Friday from 7 AM to 7 PM at 1-800-772-1213 or 1-800-325-0778 (TTY Services).