Accounting for a quarter of a school's impact on student achievement, principals are the leverage point for education reform and the primary drivers of school improvement. School leaders have a greater influence on all students than teachers, and are the best long-term investment in effective teaching at scale. The current system of principal preparation needs to be overhauled. Changes to principal preparation will accelerate the pace of improvement and ensure all preparation programs are preparing the candidates we need to deliver on the promise of education reform. State licensure systems should also be revamped to ensure that future principals demonstrate readiness before becoming school leaders, as well as ongoing success, to retain their licenses. In order to build a pipeline of school leaders ready to lead in this new era of reform, this brief recommends federal policymakers: (1) Invest in innovative principal preparation; (2) Encourage states to be open to all forms of principal preparation; (3) Require greater transparency of results; (4) Encourage states to hold all preparation programs accountable for results; and (5) Invest in states that want to pilot new approaches to certification and licensure. [For the full series, see "Prioritizing Leadership: New Leaders' Federal Policy Platform" (ED559351).]