Policies are implemented in complex networks of organizations and target populations. Effective action often requires managers to deal with an array of actors to procure resources, build support, coproduce results, and overcome obstacles to implementation. Few large-n studies have examined the crucial role that networks and network management can play in the execution of public policy. This study begins to fill this gap by analyzing performance over a five-year period in more than 500 U.S. school districts using a nonlinear, interactive, contingent model of management previously developed by the authors. The core idea is that management matters in policy implementation, but its impact is often nonlinear. One way that public managers can make a difference is by leveraging resources and buffering constraints in the program context. This investigation finds empirical support for key elements of the network-management portion of the model. Implications for public management are sketched.