This article summarizes the current knowledge of response-to-intervention (RTI) models in preschool settings, with an emphasis on evaluating the strengths and weaknesses of our current research base. Particular attention is given to the unique challenges of high-risk preschool settings. Presently, sufficient empirical support exists to begin establishing tiered intervention systems and building teacher capacity. Lacking, however, are valid and reliable assessment tools and insufficiently trained personnel to support a data-based decision-model within high-risk preschools. We conclude that organizational development should focus on building teacher capacity, establishing high-quality classroom instruction, and planning for sustainable programs, with adoption of a full RTI service delivery model serving as a long-range aspirational goal. C 2011 Wiley Periodicals, Inc.Over the past decade, rapid changes have occurred in general educational practice to increase the focus on early identification of and intervention for students considered at risk. The aptly named response-to-intervention (RTI) model of service delivery is generally described as a multitiered model whereby students receive interventions of increasing intensity, with movement from one level to another based on demonstrated performance and rate of progress (Gresham, 2007). This sizable paradigm shift has been influenced in part by recent special education legislation, which permits the use of RTI as an alternative to the traditional "IQ-achievement discrepancy" model of learning disability identification and allows up to 15% of federal special education funding to be allocated toward early intervening services (Individuals with Disabilities Education Improvement Act, 2004). Moreover, RTI has gained favor in light of mounting evidence suggesting that intensive intervention during the primary grades is effective for remediating academic difficulties (e.g., Vellutino, Scanlon, Small, & Fanuele, 2006;. Practitioners may also intuitively gravitate toward an RTI model of practice, which has more ideological appeal than traditional models in the sense that it emphasizes identifying and solving problems as soon as possible rather than waiting for students to fall far behind their peers before providing additional services (e.g., Vaughn & Fuchs, 2006).Currently, much of the published literature on full-scale RTI implementation is focused on conceptual and logistical issues related to RTI. Furthermore, a majority of the empirical studies relevant to RTI is focused either on case studies of RTI implementation in particular schools or on intensive intervention with students in the early elementary grades. Dozens of studies have documented the effectiveness of specific interventions for remediating skill deficits in reading (e.g., Case et al