Successful welfare reform is difficult to achieve in practice and to study in theory because the linkages between policy reforms and the actions of clients of the system are many, long, and loose. Reformers can change organizational structure, funding amounts and requirements, as well as mandates. They hope that these reforms will change the behavior of workers who will implement the reforms. In turn, changed behavior of employees and welfare agencies are presumed to change the behavior of clients. Evaluating welfare reforms requires that information about policy changes, organizational changes, changed behavior by workers, and ultimately changed client behavior all be examined empirically and the results combined into a coherent whole.This paper proposes that system dynamics models may be a new tool in the analyst’s toolchest that can help to create integrated theories of welfare reform as well as help to integrate results from empirical studies of welfare reform. Below we present a first cut system dynamics model of the implementation of portions of the welfare reform legislation of 1988. This effort is designed to illustrate how system changes, changes in worker behavior, and client behavioral choices might be simultaneously analyzed within the context of a singe feedback system. Of course, the hard work of elaborating and empirically validating the structure of this simple model still remains before us.