The search for alternative indicators of school quality has ignored a powerful data point that most schools already collect--a student's grade point average. Might it also be used to evaluate schools? To find out, we asked the University of Maryland's Jing Liu and co-authors Seth Gershenson (American University) and Max Anthenelli (UMD) to conduct parallel analyses of nearly a decade of student-level course and demographic data from Maryland and North Carolina. Overall, the results suggest that GPA-based indicators of middle school and high school readiness are a potentially valuable supplement to test-based value-added measures.