This article describes elements of an approach to research and development called "design-based implementation research." The approach represents an expansion of design research, which typically focuses on classrooms, to include development and testing of innovations that foster alignment and coordination of supports for improving teaching and learning. As in policy research, implementation is a key focus of theoretical development and analysis. What distinguishes this approach from both traditional design research and policy research is the presence of four key elements: (a) a focus on persistent problems of practice from multiple stakeholders' perspectives; (b) a commitment to iterative, collaborative design; (c) a concern with developing theory related to both classroom learning and implementation through systematic inquiry; and (d) a concern with developing capacity for sustaining change in systems.