The last year has found critics and advocates of the Common Core State Standards (CCSS) duking it out in the political arena. The Thomas B. Fordham Institute, an ardent supporter of high standards for some seventeen years, has recently lurched out of the safe haven of think tankery and into the boxing ring. Yet wherever one stands on the merits of the Common Core, one thing is certain--all the political posturing and mudslinging distract attention and energy from the crucial work of implementation. Like it or not, the Common Core State Standards are in place in forty-five states and the District of Columbia--and in many of those jurisdictions, educators are hard at work trying to operationalize them in their schools and classrooms. How's it going so far? In a word: bumpy. A handful of studies--surveys of state education officials, mostly--paint a discouraging picture. Clearly, lots more monitoring and evaluating lies ahead. Yet one important inquiry that's been lacking--until now--is an in-depth examination of real educators in real districts as they earnestly attempt to put the CCSS into practice. So, the authors set out to find those instructors and the districts in which they teach. Their goal was to peer into this void via an up-close look at district-level, school-level, and classroom-level implementation in a handful of jurisdictions. They sought out "early implementer" districts that have moved with fair speed to implement the new academic standards--most of them well ahead of their own state timelines for doing so--in the hope that they would reveal lessons worth sharing with the broader field. To conduct the study, the authors teamed up with Education First, a consulting firm founded by standards-reform veteran Jennifer Vranek, who a decade earlier had herself launched Achieve's American Diploma Project--which is often viewed as the precursor to the Common Core standards. With plenty of feedback from additional experts, including some at Fordham, the team identified four early implementer districts that appeared worthy of scrutiny: (1) Kenton County (KY); (2) Metro Nashville (TN); (3) Illinois's School District 54 (Schaumburg and vicinity); and (4) Washoe County (Reno, NV). In each district, the analysts probed five areas that are key to smooth implementation of any standards-based reform: communications, leadership, curricular materials, professional development, and assessment and accountability. In Part One, the report is organized by these categories, offering a rationale for why each matters for effective transition to the new standards, a brief description of the state of Common Core implementation in the respective area, and the major themes and findings that crosscut these four early implementers. In Part Two, the authors offer some advice, cautions, and recommendations for the field based on their observations in the districts that were assessed. Part Three includes individual case studies for each of the four districts, explaining their approach and detailing their Common Core implementation efforts in depth. Two appendices include: (1) Methodology; and (2) The Depth of the Change: What's Different under the Common Core? [Foreword and Summary by Amber M. Northern and Michael J. Petrilli.]