A randomized experiment involving a longitudinal sample of 4,890 children in 59 North Carolina mid-high poverty and high poverty elementary schools was conducted to examine the effects of a scaffolded summer reading intervention in which children (a) participated in teacher-directed comprehension lessons at the end of the school year and (b) were mailed ten books to read at home during the summer months. After one academic school year, children completed a standardized reading comprehension test, classroom teachers rated children’s reading engagement, and children nominated peers who provided book recommendations. Results from ordinary least square regression models revealed positive impacts on reading comprehension that were driven by gains among girls (d = .07) rather than boys (d = .02). Among girls, teachers rated treatment group children higher than control children on reading engagement (d = .08), and classmates nominated more treatment group children than control children as recommending books to read (d = .08). The results suggest that a scaffolded summer reading intervention can generate spillover effects during the school year on girls’ reading comprehension, reading engagement, and peer advice networks.