Seven general surgeons in a prepaid group practice previously shown to have a mean operative work load of 9.2 hernia equivalents (HE) per week were found to have a standardized mean daytime working week of 56.2 hours, exclusive of evening activities of which 50.7 hours were devoted to professional activities. The surgeons also devoted a mean of 6.7 evening hours per week to professional activities for a mean net professional week of 57.4 hours. Comparisons with a population of previously studied community surgeons revealed that the prepaid group surgeons were able to produce a surgical output more than double that of the community surgeons while devoting only one and a half as much time to professional activities. Economies in the utilization of surgical manpower in the prepaid group appear to stem from: 1) restriction of practice setting to a single geographic location, 2) restriction of patients to surgical patients, 3) reduced surgeon waiting time in the office, and 4) the utilization of paraprofessional personnel for selected operative assisting. These economies were achieved while the prepaid group surgeons were observed to average more time per patient visit both on rounds and in the office than the community surgeons.