Although public-sector motivation is conceived of as dynamic, and responsive to organizational stimuli, few empirical works have treated it as such. As a result, we have little understanding about how bureaucrats’ motivations change over time or about the relative impacts of intra- and extraorganizational influences. This study contributes by examining an entering group of police officers during the first 2 years of their employment. Its findings show modest change across a variety of motives over the course of the study. At each time they were contacted, the strongest predictors of an entrant’s motivations were his or her entering motivations. However, formal and informal organization influences were also associated with entrants’ motives and the amount of change appeared to increase over time. The article concludes by considering the implications of these findings for public management research and practice.