To implement Response to Intervention with intermediate-grade struggling readers, there is a need for interventions that are responsive to individual student needs, and sufficiently comprehensive to support the many dimensions of the reading process. This research examined the efficacy of such an intervention, the Interactive Strategies Approach-Extended (ISA-X), which was provided by public school teachers in a daily, one-to-one format to grade 4 struggling readers with individualized education programs. Half the students received the intervention in the fall semester while the others served as a wait-list control group who received the intervention in the spring. After the fall intervention, struggling readers had significantly higher scores than control students on measures of reading comprehension and accuracy; effects on New York State's high-stakes language arts assessment approached significance. Regression analyses showed significant intervention effects on measures of basic reading skills and social studies vocabulary; effects on a measure of fluency were not significant. (Contains 3 tables and 2 notes.)