Researchers and policymakers have pointed to the lagging scores of eighth graders on international, national, and state assessments as evidence that students are not prepared to meet high academic standards and that middle grades reform is needed. In response to these concerns, educators have introduced reforms designed to provide middle-level students with academically challenging instruction and developmentally responsive programs. This literature review summarizes the components of effective middle grades reform efforts. Research conducted on the impact of middle grades reform on student academic and behavioral outcomes and on the issue of grade configuration is also reviewed.