Evaluating the impact of new teachers on student learning is a requirement for accredited teacher preparation programs. This article shares findings from a mixed methods, multiple case study investigating P-12 student learning in the classrooms of six graduates two-three years after completing a teacher preparation program. Data collection included student engagement surveys, de-identified student growth percentile scores, teacher selected pre-post assessment data, and structured phone interviews with each graduate. Results indicated a majority of students from participants' classrooms demonstrated learning growth, and participants viewed their teaching as effective. Implications for programs include pre-service opportunities to identify and respond to authentic student engagement and opportunities to build collective teacher efficacy. Additional insights describe pre-service teacher training to measure student progress and measure impact based on classroom assessments. The investigation provides a replicable case study design for teacher educators to examine relationships between teacher preparation, program graduates, and P-12 student outcomes.