At present, there is no requirement for local Head Start programs to link or share their data with other state data systems. However, several states are making advances toward linking and/or sharing data across their state's K-12 data system or other services' data systems. In this process, states have encountered some challenges and have had to tackle issues related to data privacy and security, among others. To better understand some of the challenges, successes, and strategies behind this work, the Early Childhood Data Collaborative (ECDC) contacted and interviewed a sample of Head Start and state early childhood leaders in a dozen states. Based on these interviews, this brief from the ECDC examines the actions some states have taken in linking Head Start data to other state systems. It describes the importance of including Head Start data in a coordinated early care and education data system, relays what we learned about current data linkage steps across states, and presents action steps for state and federal leaders. (author abstract)