Personalization for academic and social-emotional learning (PASL) is a systemic approach to high school reform that works to strengthen and bridge preexisting academic and social-emotional systems within schools and classrooms. Analyzing student administrative records from 12 schools in a large Florida urban district, we found that, on average, PASL was associated with fewer unexcused absences of ninth graders. Its effects were stronger for students with prior disciplinary incidents in increasing credits earned and reducing unexcused absences. PASL effects did not vary by student race/ethnicity or family income status. The findings provide evidence for the school reform model with an improvement-science approach and suggest directions for supporting students with middle to high school transition.