When students are underprepared for the reading, writing, math, and other demands of college, their chances of earning a postsecondary credential decrease dramatically. Sixty percent of students in community colleges take one or more remedial or developmental education courses before they can access college-level programs (Bailey, 2009), and only 25% of those students complete a credential within eight years of enrollment (Bailey, 2009). Success rates are even lower for students who have to take more than one developmental course (Bailey, Jeong, & Cho, 2010).Issues surrounding developmental education have the attention of the Obama Administration, state legislatures, community colleges, and major education philanthropies. Since 2004, initiatives and organizations such as Achieving the Dream, the Developmental Education Initiative, Completion by Design, Complete College America, Statway(TM), and others have worked on and are currently working on improving developmental education outcomes in collaboration with community colleges and state systems. In the nascent stages of reform, the lack of consensus on what it means to be college ready and the limited evidence base on how to improve outcomes in developmental education resulted in many uncoordinated efforts to redesign developmental education at the state and institutional levels. But there have been major advances in research over the last decade that have increased our knowledge about effective practice and policy to improve outcomes in developmental education.A group of national policy organizations collaborated to distill and translate the new evidence on developmental education in a joint statement titled Core Principles for Transforming Remedial Education: A Joint Statement to develop consensus on the most effective practice and policy to improve outcomes in developmental education. New evidence on assessment and placement, developmental education models, academic and noncognitive supports, and institutional and program structure suggest that radical systemic change is needed at both the institutional and state level1.The response to the Core Principles statement has been mixed. It has varied by audience, often reflecting divisions between the research and policy community, policy makers, and practitioners. For example, the research and policy community is pushing for broad scale reforms, and policymakers have latched on to certain findings-such as those providing evidence in support of a corequisite model-while ignoring other findings. Developmental education professionals, in turn, have by and large rejected implications of some research findings, interpreting them to invalidate the important work that has gone on to assist students who are not prepared for success in college-level courses. It is important that the field develop a common understanding of the evidence and what it means for institution and state policy change.This article provides a concise summary of the rationale and evidence underpinning each of the principles and describes examples of how they are being implemented throughout the nation. Each principle was presented individually in sequential order in the Core Principles statement for clarity and emphasis, but there is considerable overlap between and across them. In this article, I present them individually in sequential order with the exception of Principles 3 and 4, which are presented simultaneously. Together they reflect the primary finding from specific, recent studies on developmental education-that students just under the college proficiency cut score do not benefit from developmental education and are better served by enrolling in college-level courses with embedded academic support-that is central to reform (Bettinger & Long, 2005; Calcagno & Long, 2008; Martorell & McFarlin, 2011). I close with a discussion of what the Core Principles statement suggests for next steps in developmental education reform. …