Objective: Implementation of evidence-based treatments in funded trials is often supported by expert case consultation for clinicians; this may be financially and logistically difficult in clinical practice. Might less costly implementation support produce acceptable treatment fidelity and clinical outcomes? Method: To find out, we trained 42 community clinicians from four community clinics in Modular Approach to Therapy for Children (MATCH), then randomly assigned them to receive multiple lower-cost implementation supports (LC) or expert MATCH consultation plus lower-cost supports (CLC). Clinically referred youths (N = 200; ages 7–15 years, M = 10.73; 53.5% male; 32.5% White, 27.5% Black, 24.0% Latinx, 1.0% Asian, 13.5% multiracial, 1.5% other) were randomly assigned to LC (n = 101) or CLC (n = 99) clinicians, and groups were compared on MATCH adherence and competence, as well as on multiple clinical outcomes using standardized measures (e.g., Child Behavior Checklist, Youth Self-Report) and idiographic problem ratings (Top Problems Assessment). Results: Coding of therapy sessions revealed substantial therapist adherence to MATCH in both conditions, with significantly stronger adherence in CLC; however, LC and CLC did not differ significantly in MATCH competence. Trajectories of change on all outcome measures were steep, positive, and highly similar for LC and CLC youths, with no significant differences; a supplemental analysis of posttreatment outcomes also showed similar LC and CLC posttreatment scores, with most LC–CLC differences nonsignificant. Conclusions: The findings suggest that effective implementation of a complex intervention in clinical practice may be supported by procedures that are less costly and logistically challenging than expert consultation.