Post-training consultation support is linked to improvements in evidence-based treatment fidelity following initial training, but little is known about what makes it work, and how clinician-level factors may moderate its effects. This study examined the adherence and competence of N = 33 school-based clinicians trained to provide modular Cognitive Behavioral Therapy to youth, while receiving ongoing consultation. We examined two aspects of consultation as predictors of growth in adherence and competence, consultation dosage and use of session audio review. We also examined several clinician-level predictors of fidelity growth, including education, years of experience, burnout, and self-efficacy. Fidelity was rated by both independent observers and consultants, with differing findings. Independent observer ratings of adherence and competence did not change during consultation, and were not associated with any predictors. Consultant ratings of competence showed a trend toward growth during consultation. Greater clinician self-efficacy and years of experience were associated with lower initial consultant-rated competence, but more rapid growth over time. Higher consultation dosage and use of session audio review were negatively associated with growth in consultant-rated competence. These findings reinforce the need for further study of the active ingredients of consultation (i.e. consultation practices that help clinicians improve their treatment implementation), and the factors associated with perceptions of consultant fidelity raters.