We present the results of a study of local education agency (LEA)-based interventions to improve the reading outcomes of struggling readers in sixth grade. The sample included 1,076 intervention students and 3,644 comparison students. Regression discontinuity was used to evaluate intervention impact. The study contributes to the field by demonstrating (a) the importance of conducting rigorous evaluations of existing school interventions to understand the true impact of evidence-based practices when implemented under local circumstances and constraints, and (b) the use of regression discontinuity as an evaluation design is feasible within typical school settings. Implications for the study are discussed, especially in terms of providing a model for evaluation of LEA-driven interventions in the middle grades.