The Teacher-Student Data Link (TSDL) Project brought states and school districts together to work on a common approach to one of the most critical components of their educational data systems — the link between teachers and students' outcomes. Across the nation, states are looking to use accountability data to increase student learning. Leveraging the collective experiences, knowledge, and resources of the participating states, the TSDL project developed a common, best practice framework for a teacher of record definition, as well as identified processes such as roster verification for collecting and validating linked teacher and student data. The Center for Educational Leadership and Technology (CELT) conducted the project, with funding from the Bill & Melinda Gates Foundation and guidance and dissemination support from the Data Quality Campaign (DQC).