Most Medicare recipients are enrolled in both Medicare Part A and Part B. If you're not sure if you have Part A or Part B, check your red, white and blue Medicare card. If you have Part A, "Hospital (Part A)" is printed on the lower-left corner of your card. If you have Part B, "Medical (Part B)" is printed on the lower-left corner of your card. Both will be listed for people enrolled in both parts of Medicare.