On January 1, 1992, the Medicare program implemented a new payment system for physician services based on the Resource Based Relative Value Scale (RBRVS). The RBRVS has been widely accepted as a rational and systematic approach to measuring the resource costs associated with physician services. In addition to deriving physician payment rates, the RBRVS provides a useful metric that allows the measurement and comparison of provider utilization rates and productivity across physicians performing a varied mix of services. In this study we describe the measurement of physician work, discuss alternative ways in which work values can be used to monitor physician service utilization (e.g., profiling physician practice patterns), measure physician productivity, and determine physician compensation.