In this study, we tested the outcomes of access to a Response to Intervention (RtI) model in kindergarten or in first grade on end-of-Grade-2 reading achievement and placement in special education. Across five schools, 214 students who began having access to Tier 2 intervention in kindergarten or first grade were compared in Grades 1 and 2 with 208 cohort peers who were average readers, and 102 historical control condition second grade poor readers who did not receive Tier 2 intervention. Results found significant effects on reading achievement for access to RtI in kindergarten at the end of first grade (effects averaged 0.48), but not in second grade, except for students who were English Language Learners (ELL), who showed an advantage through the end of second grade. Students with access to RtI overall had significantly higher outcomes at the end of Grade 2 than students in the historical control, with no differences due to ELL status. No significant difference in the proportion of students placed in special education was noted; however, a greater proportion of the students found eligible as LD had poor reading scores if they were placed after participating in RtI. [This paper was published in "Journal of Learning Disabilities" v47 n4 p307-328 Jul-Aug 2014 (EJ1042218).]