Federal law requires that, at a minimum, states assess high school students at least once in English language arts/literacy (ELA), mathematics, and science; these results are used for school accountability. With states' recent transitions to new assessments and accountability systems, Achieve wanted to know more about how these varied assessments, with varied purposes, matter for students and schools. In March 2019, they compiled a list of each state's required 2018-19 high school assessments in mathematics, ELA, science, social studies, and career readiness. Next, they analyzed whether and how the assessments matter for students and for schools, and whether states have assessments that matter for both students and schools. Finally, they analyzed whether states have created statewide policies that signal to students in high school whether they are ready for college-level work based on performance on a high school assessment. The findings are discussed in this report.