The process of formally continuing the medical staff membership of a physician or other health care professional, along with specific privileges. After the initial appointment to the staff, reappointment must take place at regular intervals (usually every year or two). During the reappointment process, the performance of the professional is evaluated, so that a proper determination can be made regarding renewal (or increase or decrease) of clinical privileges. If privileges are to be decreased or discontinued, certain due process procedures are required.