In United States and Canada, an attending physician (also known as a staff physician or supervising physician) is a physician (usually an M.D., or D.O. in the United States) who has completed residency and practices medicine in a clinic or hospital, in the specialty learned during residency. An attending physician typically supervises fellows, residents, and medical students. Attending physicians may also maintain professorships at an affiliated medical school. This is common if the supervision of trainees is a significant part of the physician's work. Attending physicians have final responsibility, legally and otherwise, for patient care, even when many of the minute-to-minute decisions are being made by house officers (residents) or non-physician health-care providers (i.e. physician assistants and nurse practitioners). Attending physicians are sometimes the 'rendering physician' listed on the patient's official medical record, but if they are overseeing a resident or another staff member, they are 'supervising.'