One of three components used in the formula to develop relative value units (RVUs) for each medical service performed. PE consists of salaries, fringe benefits, and purchase and use of medical equipment and supplies. The other two components are (1) amount of physician work and (2) the cost of professional liability insurance. These three RVUs are then adjusted according to geographical area and used in a formula to determine the resource-based relative value scale (RBRVS) for the Medicare fees published annually in the Federal Register.