This study provides a first look at how student college- and career-readiness have progressed in the early years of the Common Core State Standards (CCSS) implementation. It is motivated by concern that changes triggered by the standards transition might be disruptive to student learning in the short run, even when those changes may become beneficial once fully implemented. Using longitudinal administrative data from Kentucky, an early adopter of the CCSS, we followed three cohorts of students from the end of the 8th grade to the end of the 11th grade and found that students exposed to the CCSS--including students in both high- and low-poverty schools--made faster progress in learning than similar students who were not exposed to the standards. Although it is not conclusive whether cross-cohort improvement was entirely attributable to the standards reform, we found that students made large gains in proficiency in the years immediately before and after the transition. Additionally, we found student performance in subjects that adopted CCSS-aligned curriculum framework experienced larger, more immediate improvement than student performance in subjects that carried over last-generation curriculum framework.