CREDO’s National Charter School Study is the most comprehensive research on the charter sector to date. Over the course of three study reports, CREDO illuminated the impact of public charter schools over the past twenty years. The most recent report, the National Charter School Study III, includes 81% of tested public school students across the country—one of the largest student-level datasets to date. Due to the comprehensive nature of the data sets, and the length of time over which CREDO has studied charter schools, this research is significant in supporting conversations about public charter schools at the state and national level. Nationally, CREDO results showed that charter school students outpaced their traditional public school peers across math and reading, advancing their learning by 6 and 16 days, respectively. Results are more impressive for historically underserved student groups, with students in poverty, Black, and Hispanic students in charter schools having stronger growth than their TPS peers. This data makes the case that public charter schools have a significant, positive impact on students. National data also illuminated areas for improvement, such as serving students with disabilities, driving discussions around how to support the sector in providing strong outcomes for all student groups.