Purpose The aim of this study was to analyze variability in study withdrawal rates among academic neuroradiologists participating in a utilization management (UM) program. Methods The activities of 5 academic neuroradiologists participating in a UM program were assessed. The project period spanned 42 months. Participating neuroradiologists received identical training and used identical rule sets to evaluate the appropriateness of outpatient CT and MRI studies. Neuroradiologists could approve studies on the basis of available electronic data or contact referring physicians for further information. The rate of withdrawals (defined as “study not performed by consensus” or “study changed by consensus” with the referring physician) was compared among the neuroradiologists. Results A total of 5,256 studies were reviewed (mean, 1,051; median, 1,043). There were 573 studies (10.9%) not performed by consensus and 298 studies (5.7%) changed by consensus, resulting in a total of 871 withdrawals (16.6%). Among the neuroradiologists, withdrawal rates varied by approximately a factor of 2 (mean, 16.5%; median, 15.2%; range, 12.8%-23.5%). Although rate of studies not performed by consensus varied by approximately a factor of 2 (mean, 10.8%; median, 8.1%; range, 7.6%-18.0%), the rate of studies changed by consensus showed little variation (mean, 5.7%; median, 5.5%; range, 4.8%-6.6%). Conclusions Variability in withdrawal rates was related to cases in which referring physicians were asked not to perform studies; there was little variation when referring physicians were asked to change studies. These data imply agreement among the neuroradiologists regarding appropriateness of rule sets but suggest that personality characteristics such as persuasiveness, persistence, and desire for conflict avoidance may play an important role in outcomes.