The purpose of this study was to examine the effects of 42 hr of reading instruction during summer on (a) reading performance of rising second and third graders (n = 39), who were from low-income families and who read below grade level, and (b) the fall reading outcomes between this group and their nonparticipating peers. The intervention was based on evidence-based practices and included instruction on foundational skills, sentence writing, and shared reading. Classroom teachers were trained as interventionists and provided instruction in small (2:1) groups while older adult volunteers facilitated shared reading one on one. Results indicated statistically significant growth on oral reading fluency (ORF) (d = 0.89 to d = 1.16) during summer for the intervention group, and significantly higher ORF (g = 0.34) or accuracy (g = 0.27) compared to peers. There was no evidence of summer learning loss on tests of phonemic awareness, decoding, word reading fluency, reading comprehension, spelling, or writing for intervention participants. Results underscore the role of summer learning programs in mitigating learning loss for students who read below grade level and are from low-income families.