Purpose: This study examines leadership development in three high schools in urban, suburban, and rural districts. Teacher leadership, leadership development, and work design and redesign literature informed the design of a model that was used as a lens to analyze each school across diverse contexts. Research methods: Data were collected from each of the three high schools. Interviews were conducted in spring 2016 with 56 teachers and 8 administrators (n=64). Findings: Schools' efforts to develop leadership were dependent on five key factors: principal support, teacher leader capacity, school conditions, development opportunities, and leadership practices. Variations in these factors were associated with differences in leadership development in all three districts. Implications: This study has implications for how schools and districts understand both formal and informal leadership development efforts of administrators and teachers within broader national, state, and district contexts.