The national high school graduation rate reached its highest level in U.S. history--82 percent--during the 2013-14 school year (Kena et al., 2016)--but dropout remains a persistent problem in the Midwest and nationally. Early warning systems that use research-based warning signs to identify students at risk of dropping out have emerged as one strategy for improving graduation rates. More robust, comprehensive early warning systems also emphasize matching and assigning identified students with interventions to help them get on track for graduation (Neild, Balfanz, & Herzog, 2007) and continued monitoring of students' progress in these interventions. However, little is known about the impact of the use of early warning systems on students and schools. This study examines the impact and implementation of one early warning system--the Early Warning Intervention and Monitoring System (EWIMS)--on student and school outcomes in three Midwestern states. The study examines the following research questions after the first year of EWIMS adoption: (1) What is the impact of EWIMS on indicators of student risk? and (2) What is the impact of EWIMS on student progress in school? This study provides rigorous initial evidence that, even with limited implementation during the first year of adoption, using a comprehensive early warning system can reduce the percentage of students who are chronically absent or fail one or more courses. [SREE documents are structured abstracts of SREE conference symposium, panel, and paper or poster submissions.]