This report examines out-of-school suspension data from the Civil Rights Data Collection (CRDC) from the 2011-12 school year through 2017-18, tracking trends over time and differences in suspension rates of students based on their race and ethnicity, school level, and disability status. Data is presented at national and state levels, and because out-of-school suspensions are concentrated in secondary schools, state-level findings are focused on secondary school students. The factors associated with the use of suspension is also described. The report expands on work the Learning Policy Institute (LPI) previously supported documenting the prevalence and impact of exclusionary discipline. In addition, this report is part of LPI's "Inequitable Opportunity to Learn" series, which uses the CRDC data to understand the extent to which historically underserved students experience inequities in their opportunities to learn--including who teaches them, what they are taught, and how they are treated. The report describes suspension rates and gaps at the national level and state levels. It then describes factors that influence the use of suspensions and disparities in suspension rates and concludes with recommendations for policymakers. [For "Protecting Students' Civil Rights: The Federal Role in School Discipline," see ED626607. For "Inequitable Opportunity to Learn: Student Access to Certified and Experienced Teachers," see ED603398. For "Inequitable Opportunity to Learn: Access to Advanced Mathematics and Science Courses," see ED626612.]