Performance assessments as part of a robust assessment system in which students show what they know by writing an essay, curating a portfolio of work, or conducting original research. Ultimately, performance assessments can allow students to demonstrate college and career readiness through a culminating assessment—such as a graduate capstone or senior portfolio defense. The report on which this brief is based documents the work of three districts involved in the California Performance Assessment Collaborative: Los Angeles, Oakland, and Pasadena Unified School Districts. Through interviews, focus groups, and observations, we identify the key conditions needed to support the implementation of culminating performance assessments at the district, school, and classroom levels. We also examine students’ and educators’ perceptions of outcomes related to participation in performance assessment initiatives. Finally, we summarize lessons from the districts’ experiences with performance assessments and present associated recommendations to district leaders and state policymakers.