Transforming schools through mastery learning may solve education's existential crisis, offering today's learners the relevance and individualization they need while returning to the most ancient form of assessment, proving that learning has occurred. Mastery learning requires significant change to all the norms and practices of school, altering time, space, culture, technologies, and pedagogies. Ira David Socol and Pam Moran share how, in Virginia, Kentucky, and Nevada, statewide innovation networks provide schools with the support, coaching, and peer encouragement required for sustainable change. Backed by both public and private organizations, these networks meet in-person and virtually, work synchronously and asynchronously, and communicate with stakeholders to build fundamental change.