Robust and Equitable Measures to Identify Quality Schools (REMIQS) is a new initiative that seeks to build a comprehensive definition of high-quality nonselective public high schools serving student populations often underserved by the public education system. This concept brief describes the motivations behind this study and the concepts that may characterize high-quality schools, as discerned from the literature and discussions with leaders in the field. The framework presented here could be a resource to educators, policymakers, and others interested in the components of school functioning that may influence student outcomes in meaningful ways.