This report is the outcome of a request to the National Academies of Sciences, Engineering, and Medicine to undertake a study to look at the summertime experiences of children and youth in the following four outcome domains of well-being: (1) academic learning and opportunities for enrichment; (2) social and emotional development; (3) physical and mental health and health-promoting behaviors; and (4) safety, risk-taking, and anti- and pro-social behavior. (author abstract)