Systematic differences in the incidence of corruption between countries can be explained by models of coordination failure that suggest that corruption can only be reduced by a “big push” across an entire economy. However, there is significant evidence that corruption is often sustained as an organizational culture, and can be combated with targeted effort in individual organizations one at a time. In this paper, we propose a model that reconciles these two theories of corruption. We explore a model of corruption with two principal elements. First, agents suffer a moral cost if their corruption behavior diverges from the level they perceive to be the social norm; second, the perception of the norm is imperfect; it gives more weight to the behavior of colleagues with whom the agent interacts regularly. This leads to the possibility that different organizations within the same country may stabilize at widely different levels of corruption. Furthermore, the level of corruption in an organization is persistent, implying that some organizations may have established internal “cultures” of corruption. The organizational foci are determined primarily by the opportunities and (moral) costs of corruption. Depending on the values of these parameters, the degree of corruption across departments may be relatively uniform or widely dispersed. These results also explain another surprising empirical observation: that in different countries similar government departments such as tax and education rank very differently relative to each other in the extent to which they are corrupt. This is difficult to explain in incentive‐based models if similar departments face similar incentives in different countries.