This introduction to the special issue on Reading Recovery situates the enterprise in a broader educational reform context that has placed a priority on developing and fielding large-scale, systemic interventions that support ambitious instructional practice and student outcomes. Within this context, Reading Recovery is examined as an evolving, adaptive "epistemic community" in which tutors, teachers, leaders, coaches, and developers collaborate to produce, use, and refine the practical knowledge needed to support and sustain success among large numbers of struggling readers. Viewing Reading Recovery as an epistemic community provides a framework for more deeply engaging the articles in this special issue, for reflecting on Reading Recovery's history of success, and for speculating about Reading Recovery's future in rapidly evolving policy and reform contexts.