Jefferson Education Accelerator contracted with Empirical Education to study the effectiveness of the implementation of Agile Mind's "Agile Assessment" in an urban school district in the Northeast United States during the 2016-17 school year. "Agile Assessment" is a system for building formative assessments that includes research-based items aligned to state standards. This study focused on students enrolled in Algebra and examined the impact of "Agile Assessment" usage on student performance, as measured by the Partnership for Assessment of Readiness for College and Careers (PARCC) Algebra assessment. The study compared achievement for students in two groups: one group of students in grades 9 through 12 who implemented "Agile Assessment," and the other group who did not, adjusting for the differences in student characteristics. A positive impact of "Agile Assessment" on the PARCC Algebra assessment was found, and these impacts were significant across multiple student subgroups. Additionally, the average "Agile Assessment" score was found to have a positive association with student outcomes on the PARCC assessment.