In this issue of JAMA Pediatrics, Brotman et al1 report the 3-year follow-up results of a cluster randomized clinical trial of ParentCorps, a prekindergarten intervention that focuses dually on teacher professional development and family-based mental health. Prior studies2-4 of ParentCorps have already revealed a positive effect on child behavior and kindergarten academic skills. In the study by Brotman et al,1 423 children from 5 urban public schools whose prekindergarten programs incorporated ParentCorps were compared with 369 children from 5 similar schools whose prekindergarten programs did not. The children were followed up through second grade with adequate retention in both groups. Teachers rated child academic performance and mental health problems annually. According to both measures, ParentCorps students fared better, with sustained differences over time.