This article examines the ability of social accountability to spur gradual institutional change at the municipal level, using the case of citizen oversight agencies (COAs) for police agencies. Using the gradual change framework and the social accountability framework to guide the empirical strategy and data collected through an original survey of COAs, the authors test the impact of COAs on institutional outcomes in policing. We find that, in accordance with the gradual change framework, the degree to which a COA reduces racial disparity in policing outcomes depends on its scope of authority and the degree of discretion afforded by existing institutions to police officers. In general, the wider the scope of authority, and the broader the discretion afforded by existing institutions, the greater the likelihood of change in institutional outcomes.