The federal Gun-Free Schools Act (GFSA) was introduced into law as part of the Improving America's Schools Act of 1994. The federal law requires states funded under the Elementary and Secondary Education Act (ESEA) of 1965 to have a state law in effect that requires local education agencies (LEAs) to expel students for firearm offenses for a period of no less than 1 year. School administrators may modify these expulsions on a case-by-case basis for students with disabilities in compliance with the federal Individuals with Disabilities Education Act (IDEA). The GFSA also mandates that states and LEAs enact policies to refer students to the criminal justice system when they are in possession of a firearm on school property. Under the provisions of the GFSA, U.S. public school systems must report any incident when a student brings a firearm to school or is in possession of a firearm on school property. The Gun-Free Schools requirement applies to all 50 states, the District of Columbia, and Puerto Rico; the Bureau of Indian Education (BIE); and the insular areas of American Samoa, the Commonwealth of the Northern Mariana Islands (CNMI), Guam, and the U.S. Virgin Islands. The Office of Safe and Supportive Schools (OSSS) within the U.S. Department of Education's (Department's) Office of Elementary and Secondary Education (OESE) is responsible for compiling information on firearm offenses. The data collection falls under the Student Support and Academic Enrichment grant program authorized under Title IV, Part A of the ESEA. States submit GFSA data through the Department's ED"Facts" Submission System (ESS), a centralized system for obtaining and validating K-12 performance data for education planning, policymaking, management, and budget decision making. Since the school year (SY) 2015-16 annual data collection, the OSSS has been collaborating with the National Center for Education Statistics (NCES) and the National Center on Safe Supportive Learning Environments (NCSSLE) to establish a data quality review and state feedback process to provide technical assistance to state education agencies (SEAs) to help enhance data quality and completeness. The SY 2018-19 report describes the GFSA quality review process and the results of the initial quality assessment, including a summary of improvements in data submissions resulting from review and feedback to states. The report also summarizes data on firearm incidents for SY 2018-19, including detail on the number of incidents reported by student grade level, weapon type, and disciplinary action resulting from violations of the law. The report presents comparisons to incident counts and rates from previous reporting periods to explore trends in incident rates across time.