The primary aim of the Middle School Intervention Project (MSIP) is to evaluate the impact of a multi-component intervention for struggling adolescent readers on reading outcomes. The intervention consists of: (1) targeted, Tier 2 reading and (2) school engagement interventions, and (3) data-based-decision-making (DBDM) teams to review and act on student data. A critical concept in MSIP is that 6th grade students are screened into the targeted, Tier 2 intervention based on 5th grade reading scores. This screening function allows for a regression discontinuity design (RDD). Use of the RDD allows educators to evaluate existing practices in schools, rather than randomly assign half of the schools to receive a prescribed intervention, as in a traditional RCT. Thus, this study is also a test of RDD as a feasible means for conducting rigorous evaluation research with SEAs and LEAs. The purpose of this presentation is to demonstrate the use of RDD to evaluate the impact of a multi-component intervention for struggling readers in middle school. The authors examine the impact of the intervention on the Oregon Assessment of Skills and Knowledge (OAKS), a high-stakes, statewide reading assessment. (Contains 1 table.)