The aim of this brief is to describe a key contributor to the persistent disparities found in student learning outcomes in Chicago Public Schools (CPS) and to show how this knowledge can help identify specific sources of inequities in CPS, particularly for schools with predominantly Black student enrollments. The authors present a data-based approach to identifying and examining a prominent type of high-need school--the "high-churn school"--through publicly available administrative data. Both the concept of "churn" and the initial data analysis presented here can inform current CPS efforts to strengthen the processes of continuous improvement at the system level.