Achievement gaps among racial-ethnic and socioeconomic status groups are an enduring, pervasive, and multifaceted phenomenon. Therefore, efforts aimed at understanding and addressing these gaps must be developmentally and environmentally broad, involving numerous school counselor roles and tasks, including leadership, advocacy, collaboration, and strategic interventions. In this article, we first document achievement gap trends and then provide a framework for understanding and sequencing outcomes that quantify student achievement gaps. Finally, we present research that identifies critical variables influencing achievement gaps and important school counselor roles and tasks aimed at closing these gaps. The article focuses on outcomes across the developmental spectrum from elementary school through postsecondary education.