Authors: Georgia Hall, Ph.D., Laura Israel, Joyce Shortt, M.Ed. The National Institute on Out-of-School Time (NIOST) was commissioned by the Time Warner Foundation to investigate afterschool opportunities and experiences for high school age youth in 21 major cities. Particular emphasis was focused on five of the cities: Baltimore, Chicago, Denver, Kansas City, and Fort Worth. There is a solid consensus among researchers, program providers, and families that participation in constructive activities during out-of-school time hours can contribute to a youth's healthy and positive development. This paper explores some of the key issues and challenges facing program and city leaders in creating and sustaining afterschool program opportunities that engage the interest and participation of high school age youth. The authors discuss effective program characteristics and strategies for citywide collaboration, along with steps for cities and organizations to build their capacity to meet the needs of today's teen youth during the out-of-school time hours.