This article describes a teacher-led school "Mathematics and Science Leadership Academy" (MSLA) that is part of the Denver Public Schools. At MSLA, teachers collaborate to make authentic and substantive decisions about how the school operates and seek to meet each student's needs. At teacher-led schools, teachers hire their own colleagues, when appropriate fire them, observe and evaluate one another, decide what professional development will best meet student needs, set budget priorities, determine staffing structures, and more. MSLA is showing how teachers can transform schools and the teaching profession. Each day teachers practice and model the skills that they are charged with instilling in students. Teachers have ample opportunities to solve problems, collaborate, think creatively, take risks, persevere through challenges, and learn and lead with one another. The article includes an inset entitled "What's Required to Start a Teacher Led School."