Research on policy implementation and street-level bureaucracies often tackles the issue of the discretionary power at the individual level, starting with frontline workers’ freedom of action in the field. Based on an ethnographic study of the administration responsible for processing asylum requests in Switzerland, this article analyzes the issue differently: on the basis of the social, institutional, and legal mediations used by the law to guide actors’ behaviours. The analysis of the mediations between laws and practices (decisions on asylum demands) shows the importance of a collective normative power of the administration, insofar as the caseworkers and their supervisors develop “secondary implementation norms.” This article shows that there are legal and social concepts and processes that frame, steer, and constrain caseworkers’ practices in implementing the law.