According to the National Child Care Survey, approximately seven million children are spending some amount of time each day in self-care (U.S. Census Bureau, 2000). When adolescents are included in these figures, some evidence suggests the number of youth without care after school approaches 15 million (White House, 1998). The large number of children and adolescents who are unsupervised during out-of-school hours has prompted a broad national dialogue about child and youth care in communities today. The quality and accessibility of out-of-school options are important because youth without after-school opportunities are at risk for a host of negative outcomes. Afterschool programs hold great potential to equip "all" youth with the skills and attitudes necessary for participation in our increasingly complex society. Public libraries represent community spaces in which teens who seek to cultivate their passions and interests can explore, create, and make progress in a low-stakes environment. Libraries can be venues in which teens define themselves at their own pace and in personally meaningful ways (Pittman, Irby, Tolman, Yohalem, & Ferber, 2001). Communities that want to support youth must understand the powerful role civic institutions such as libraries can play during the out-of-school hours. This article describes what teens want and need after school, the public library as a youth development partner, and the library's unique role in promoting positive youth development. It goes on to highlight the Boston Public Library (BPL) as an example of a large urban library system that wants to get it right with Boston's teens. BPL leaders have identified six keys to successfully attracting and serving teenagers, each of which are discussed: (1) Create Dedicated Teen Spaces That Are "Cool"; (2) Embed Youth Voice in Governance and Program Development; (3) Offer Meaningful Teen Employment Opportunities; (4) Enhance and Expand Technology Resources; (5) Expand Collaborative Community Programming; and (6) Bolster Learning Supports and College/Career Resources.