The San Antonio Public Library proudly serves teens (ages 13 to 18) through developmentally appropriate programs and events at every location and through virtual platforms. This guide provides Teen Services Librarians and Liaisons at the San Antonio Public Library with information on how to do this successfully at their respective locations; we also invite teen-serving library staff from other library systems to explore this information. Throughout this guide, professional competencies are provided to support Teen Services Librarians and Liaisons as they interact with teens in their communities and with their coworkers as advocates for teen patrons.