Driven by research that evidences the direct impact of principals on school-wide improvements, Illinois has been working at the forefront of innovation and improvement in principal quality for quite some time. A large body of research supports the impact of school leadership on school and student outcomes. While high quality instruction is necessary for improved student learning in schools, high-quality school leadership creates the conditions for improving instruction. In a 2001 survey of 40,000 teachers nationally funded by the Gates Foundation, 96 percent of teachers ranked supportive leadership as "absolutely essential" or "very important" to retaining good teachers. Recognized for bold policy initiatives involving principal preparation and development, Illinois has received national awards and recognitions. These efforts led to the creation of a new P-12 Principal Endorsement and the mandate that all preparation programs throughout the state apply for program approval under the new requirements, which include intensive internship requirements and competency-based assessments evidencing that principal candidates are ready to lead before they are given the license to do so. The Center for the Study of Education Policy believes that the results of Illinois Public Act 96-0903, enacted in 2010, represents a substantial overhaul of leadership preparation requirements in Illinois. Key elements are proposed which represent a paradigm shift for preparation programs from "candidate as consumer" to "district as consumer." Moving beyond the simple outcome of program graduates securing administrative positions, the new requirements focus much needed attention on the impact principal preparation ultimately has on school improvement and student outcomes. An appendix presents comparative ISAT data between CPS students (CHI) and students outside of CPS (ILLxCHI).