Based on a three-year ethnographic study of two prisoner reentry agencies, this article explores how frontline service providers negotiate the contradictory demands of performance accountability. Performance accountability systems—collectively known as the New Public Management (NPM)—force service providers to make difficult trade-offs between these managerial goals and the substantive goals of rehabilitation. However, we know little about how frontline service providers negotiate these competing demands. I show how, despite efforts to develop distinct organizational brands, both organizations I studied responded to performance pressures and resource constraints according to a set of practices I call "defensive institutionalism." This involved strategies designed to protect organizational resources from high risk clients by (1) filtering the client pool and (2) responsibilizing clients. While these practices allowed these organizations to reconcile managerial and substantive goals in situ, they did not resolve the underlying contradictions of New Public Management. New Public Management incentivizes service providers to pursue short-term, individuated approaches to rehabilitation, and it induces isomorphism rather than innovation. I conclude by discussing the implications of these findings for current efforts to implement "evidence-based" criminal justice policies.