Nearly every state has signed on to use the Common Core State Standards as a framework for teaching English/language arts and mathematics to students. Translating them for the classroom, however, requires schools, teachers, and students to change the way they approach teaching and learning. This report examines the progress some states have made in implementing the standards, what preparations need to be undertaken, and the challenges that policymakers and educators face in achieving the goals of the standards. Articles in this supplement include: (1) "Advocates Worry Implementation Could Derail Common Core" (Catherine Gewertz); (2) "Concern Abounds Over Teachers' Preparedness for Standards" (Stephen Sawchuk); (3) "Reading on Science, Social Studies Teachers' Agendas" (Catherine Gewertz); (4) "Big Shifts Ahead for Math Instruction" (Erik W. Robelen); (5) "Standards Open the Door for Best Practices From Special Ed." (Nirvi Shah); and (6) "Language Demands to Grow for ELLs Under New Standards" (Lesli A. Maxwell).