Objective: College campuses report alcohol and other drug policy violations as the most frequent reason students receive disciplinary referrals and, thus, are mandated to programming. This study sought to determine predictors of mandated students' alcohol use frequency, and the likelihood of early-onset alcohol using college students enrolled in mandated programming engaging in current polysubstance use. Methods and participants: Employing a purposive sampling method, n = 822 participants were recruited from a pool of students who violated their university's alcohol policy between October 2019 and July 2021. Results: Data analysis revealed early-onset alcohol use (p < 0.001), gender ID (p < 0.01), Greek Affiliation (p < 0.001), ethnicity (p < 0.05), and perceived norms (p < 0.001) significantly predicted alcohol frequency. Analysis also revealed engaging in early-onset alcohol use significantly predicted current participation in polysubstance use (p < 0.01), outside of controls. Conclusions: University programs should consider exploring polysubstance use targeted interventions to mitigate these harmful behaviors and associated negative consequences.