In 2017, fifty-six percent of the principals hired statewide were new to the job, with high-poverty schools most likely to hire novice principals. During 2018 and 2019, a working group of district and charter school leaders and other education stakeholders from across the state met to explore ways to increase the effectiveness of principals leading Massachusetts schools. The Barr Foundation engaged Attuned Education Partners to facilitate this group and lead implementation of the learning agendas developed by its members. Together, they prioritized key challenges and identified solutions that research suggests are most likely to strengthen principalship and drive better outcomes for students—especially the students of color and English learners that the state is currently serving least well. This report presents their findings and insights—including recommended actions tailored to state policymakers, school system leaders, principal preparation program providers, and funders. It also offers a collection of case studies demonstrating potential solutions in action.