Recent research has shown that, at the federal level, new or amended programs typically create networks consisting of multiactor structures spanning governments, sectors, and/or agencies. This study examines the implementation structures created through the regulatory process. We find that in a majority of cases the regulatory process adds to the complexity of implementation patterns; previously simple implementation structures often became more complicated and new actors are brought into the process. Rules also serve a key function in clarifying the general language that is often used by Congress. These findings have implications for the study and practice of public administration.