The Multistate Longitudinal Data Exchange (MLDE) facilitates data sharing between states from K-12 education, higher education, and labor agencies. Its goal is to provide practitioners, policymakers, and researchers with a comprehensive data source to understand educational and career trajectories, including how these trajectories can cross state lines, to improve policies and programs serving students and provide better consumer information. The exchange, begun as a pilot in 2010, is a collaboration between the Western Interstate Commission for Higher Education (WICHE) and state agencies that house education and work data in multiple states and has been largely funded by the Bill & Melinda Gates Foundation. The Education & Employment Research Center (EERC) at Rutgers, The State University of New Jersey, has conducted research and evaluation on the inaugural years of the MLDE. This brief explores that process and the stages of developing a governance system for a multistate state-data exchange project, the Multistate Longitudinal Data Exchange (MLDE). The MLDE is designed to help states and regions develop a more holistic view of education and employment pathways, which in turn helps to inform practitioners, policymakers, and researchers. This EERC brief is one of a five-brief series that explores the development of the MLDE and details the lessons learned about building and using longitudinal multistate data systems for policy and practice.