Daily Behavior Report Cards (DBRCs) have shown to be a successful intervention for improving classroom behavior for students considered to display challenging behaviors. DBRCs have been used for students with emotional/ behavioral disorder in an effort to improve academic and social outcomes. Few studies have examined the use of DBRCs for students with intellectual and developmental disabilities (IDD). Even fewer studies have examined the intersection of young (i.e., early childhood) students with IDD in extended school year settings (ESY). The authors examined the effectiveness of DBRCs for young students with IDD in ESY settings. Four elementary students (ages 6-7) with IDD and behavior challenges who were receiving ESY services as mandated by their respective Individualized Education Plan participated in the current study. Researchers used a changing criterion single case research design, with visual analyses and Tau-U statistical analyses indicating a positive impact for each student and 1.00 effect sizes with significance (p < 0.01). Teachers demonstrated fidelity of implementation, and competence in data collection and graphing student progress.