The sweeping changes of 1996’s welfare reform legislation are more than just new policies. They represent a profound transformation of the character and structure of social policy institutions in the United States, a shift from a bureaucratic, centralized mode for income transfer, to a professional mode aimed at complex behavioral change. The evaluation community has responded with a shift from traditional impact analyses to implementation studies that get inside the skin of this new, more flexible structure. Implementation research explores the translation of concepts into working policies and programs, and evaluates how well the administrative and management dimensions of these policies work, and how the programs are experienced by all involved. Policy into Action offers state-of-the-art thinking on implementation research from leading policy researchers and evaluation practitioners.