The California Subject Matter Project is a network of nine discipline-based projects that provide rigorous professional development for K–12 educators to enhance learning for all students. With a network comprising the nine projects—History–Social Science, Science, International Studies, Mathematics, Physical Education–Health, Reading and Literature, World Language, Writing, Arts—CSMP encompasses the course content represented in California’s K–12 standards and frameworks, and covers all of the academic disciplines required to meet college entrance (“a-g”) requirements. Through 90 regional sites statewide, CSMP creates communities of practice that promote high-quality teaching, leadership, and educational equity.