This project aims to serve the national interest by supporting departmental change teams in institutions of higher education who are working to improve their undergraduate mathematics programs. The goal of this IUSE Level 1, Track 1 Institutional and Community Transformation grant, Sustaining Undergraduate STEM Transformation And Improvement Networks through Change Agent Turnover (SUSTAIN-CAT), is to better understand how STEM educational change networks sustain themselves and their efforts when people leave or shift roles (i.e., change agent turnover; CAT). It is well-documented that U.S. mathematics achievement needs to be improved for most students. Improvement efforts depend on a core group of change agents to provide leadership and momentum for a change project. Peripheral individuals are also involved (department chairs, deans, other partners), whose positional power can positively or negatively impact project progress. One constant is that across a multi-year project, the people involved change. Thus, the primary research question guiding this project is: How do institutional and community transformation projects sustain their critical change efforts through personnel turnover, while also honoring and incorporating the strengths and interests of incoming change team members? A significant contribution of SUSTAIN-CAT is the focus on planning effectively for personnel turnover; such plans are rare among existing change efforts. SUSTAIN-CAT has three main goals: (1) Le