In the US, 6.5 million children attend out-of-school time (OST) programs annually, participating in roughly three hours per day of activities typically including homework, snack and gross motor play. The specific aims of this study are to: (1) build capacity for obesity prevention in OST by infusing rigorous science-based guidelines into the National Afterschool Association standards for physical activity and healthy eating; (2) identify current physical activity and eating standards and program practices used in a targeted national sample of OST programs; (3) identify significant associations between best practices and program characteristics, components and social contextual variables; (4) disseminate information on effective implementation of standards; and (5) lay the groundwork for a subsequent project to re-assess the program cohort and develop a toolkit to help all OST programs implement the recommended standards for physical activity and healthy eating. This is a mixed-methods study using quantitative and qualitative methods. Data will be collected in ten regions of the US, representing a mix of geographic locations, urban/suburban/rural communities, school district sizes and variety of OST programs. The survey sample will include 80-100 programs within each region (500+ total) and exemplary program observations at 30 of these programs.