This study examined the efficacy of using Headsprout Early Reading (Headsprout, 2007) to supplement a balanced literacy curriculum for kindergarten and first grade students in a suburban public school system. Headsprout, which is an example of computer aided instruction (CAI), provided internet-based, supplemental reading instruction that incorporates the five critical components of reading instruction cited by the National Reading Panel (NRP, 2000). The school system implemented Headsprout as a standard protocol, Tier 2 intervention within their Response to Intervention (RTI) process. The study included kindergarten and first grade students from across the school system who were identified as at risk for reading failure based on fall Dynamic Indicators of Basic Early Literacy (DIBELS) scores. Kindergarten and first grade students identified as at risk for reading failure who participated in Headsprout were compared with matched groups of kindergarten and first grade students who did not participate in Headsprout. Overall, neither kindergarten nor first grade students who participated in Headsprout gained meaningful educational benefit from the CAI instruction provided by Headsprout beyond the benefit they received from participating in the general education, RTI Tier 1, balanced literacy curriculum that was available to all kindergarten and first grade students.