The importance of helping all children make meaningful progress in reading development is supported by legislative mandates and court rulings. The purpose of this research was to describe findings from a series of single-case design studies completed over three years to test the effects of a specific comprehensive literacy intervention, Friends on the Block, on word recognition. Participants were 18 students with intellectual and developmental disabilities (IDD) ranging in age from 6 to 13. Results were analyzed using Tau statistical procedures that indicate consistent moderate-to-strong positive effects across all participants for both sight words and decodable words. Across the 67 sight word studies the mean effect size was 0.73, and across the 8 decodable word studies the mean effect size was 0.74. Further research is needed to examine the impact of the intervention on a broader array of variables. Implications, limitations, and directions for future research are discussed.