The problem is clear: an unacceptable number of America's students are not graduating from high school, and many who do are still not adequately prepared for success in college and career. Past efforts to address this problem have only been able to achieve incremental results. Now, there is increasing recognition that in order to meaningfully solve this problem, efforts should shift from those that are narrow and often yield very slight results to those that can fully transform high schools that are failing to graduate and prepare students. Whole-school reform, a school improvement approach implemented by schools and districts for almost two decades, can bring about that change through the use of a comprehensive, unified school design that transforms all aspects of a school. As federal policymakers look ahead to the Elementary and Secondary Education Act reauthorization, they should seek to encourage increased and effective implementation of whole school reform as part of a systemic approach to school improvement. This brief describes whole-school reform, how it has been supported by federal policy in the past, what lessons have been learned from those policies, and recommendations for how federal policy can encourage and support whole-school reform in more schools facing significant challenges. (Contains 6 footnotes and 50 endnotes.)