Teachers need career pathways that provide new challenges and sustained opportunities for leadership without leaving the classroom. Better opportunities for leadership and innovative pathways help to increase the retention of strong teachers. Although few such programs existed several years ago, a growing number of states, districts, charter schools, and other organizations have recently introduced some kind of teacher-leader program. The author's research aimed to identify successful teacher-leader programs. To do so, she first examined cross-sector research (e.g., business and medicine) that identified strategies for leadership programs that aim to increase the retention of high-performing employees. She then scanned dozens of teacher-leader programs and identified programs with some evidence of a positive impact. Because so many of these models are new, however, little research or documentation exists to demonstrate their effectiveness. Her search identified only five programs with some evidence of success, such as increasing student achievement or teacher retention. Although these programs are not exemplars, they offer valuable lessons learned for developing teacher-leader systems. In this brief, Doyle overviews the cross-sector research related to leadership programs, outlines four best practices from existing teacher-leader programs, and provides next steps for state leaders interested in implementing a teacher-leader system. Throughout, she highlights different programs and strategies that have had some success in the field.