Response to Intervention (RtI) has brought about many changes in the way educational services are being provided to students who are at risk of school failure. Schools are seeking strategies that will be beneficial to more and more students, including those students whose instruction is primarily in the core, or Tier 1. Nesting proven, evidence-based practices more widely in an RtI model is discussed as an efficient strategy for closing achievement gaps and research--practice gaps. To differentiate instruction relative to RtI and the core curriculum, the application of strategies typically reserved for Tiers 2 and 3 is suggested. An example of embedding, or nesting, interventions at Tier 1 is given. Organizational tools are provided for Tier 1 whole-class, differentiated instruction in fluency training, including repeated readings. The roles of the school psychologist, teacher, and administrator in the model are considered, along with specific, targeted examples and approaches. (Contains 2 tables.)