Objectives: Advocacy for reforming financial sanctions (i.e., fees, fines, and restitution) in the juvenile justice system is growing, with a particular focus on eliminating fees. Although a key argument is that these sanctions may increase the likelihood of reoffending, studies that examine the link between financial sanctions and recidivism are limited and their results are mixed. Using administrative data on a large, diverse, and at-risk population of juvenile probationers in an urban county, we tested the impact that financial sanctions have overall—and that fees have specifically—on young people’s risk of probation violations and re-arrest over a two-year period. Hypotheses: We tentatively hypothesized that (1) financial sanctions overall would increase both probation violations and re-arrests, and (2) fees alone would increase probation violations but not re-arrests. Method: We accessed, linked, and analyzed data from county and state agencies for a sample of 2,401 youth under supervision. We applied a rigorous causal inference approach (Targeted Maximum Likelihood Estimation) combined with machine learning to test the hypotheses. Results: Financial sanctions overall modestly increased the likelihood of both probation violations (from an estimated 9%, to 14%) and re-arrests (from an estimated 54%, to 58%)—but fees alone did not significantly predict either outcome. Conclusions: Financial sanctions burden families, but are weak risk factors for recidivism. If the goal is to prevent re-offending, reform efforts could focus on broader financial sanctions than just fees, and prioritize more powerful levers like evidence-based services and supervision.