There is great variation in the content of out-of-school time programs and in the outcomes that these programs may influence. While school success is often the focus, other outcomes related to children's well-being also matter and are the focus of many out-of-school time programs. These outcomes fall within four research-based child outcome domains: (1) educational achievement and cognitive attainment; (2) health and safety; (3) social and emotional development; and (4) self-sufficiency. In this brief, the authors highlight outcomes in each of these domains and identify resources that may be of use to programs as they measure outcomes for children and youth in their programs. Forthcoming briefs will provide additional details on specific outcome topics. (Contains 3 endnotes.) [This report was sponsored by The Atlantic Philanthropies.]