On the basis of an analysis of the supply of and demand for orthopaedic surgeons, we projected that there will be 21,134 full-time-equivalent orthopaedists in the year 2010 if training continues at current levels. We estimated a demand-based requirement of 17,012 full-time-equivalent orthopaedic surgeons, indicating a surplus of 4122 full-time equivalents. In terms of orthopaedist-to-population ratios, we estimated that there will be 7.5 full-time-equivalent orthopaedists per 100,000 population in 2010 compared with a demand-based requirement of 6.0 full-time equivalents. However, we did not include estimates of the demand for orthopaedic surgeons as assistants in the operating room in our model. If an assistant orthopaedic surgeon is required for all procedures, an additional 3906 full-time-equivalent orthopaedists would be demanded, thus eliminating the surplus. The demand for an assistant orthopaedic surgeon in only half of the procedures would still lead to a sizable reduction in the surplus.