Screening, brief intervention, and referral to treatment (SBIRT) may impact future comorbidity and healthcare utilization among adolescents screening positive for substance use or mood problems. In a randomized trial sample, we compared an SBIRT group to usual care for substance use, mental health, medical diagnoses, and healthcare utilization over 7 years postscreening. In logistic regression models adjusting for patient characteristics, the SBIRT group had lower odds of any substance (Odds Ratio[OR] = 0.80, 95% Confidence Interval [CI] = 0.66-.98), alcohol (OR = 0.69, 95% CI = 0.51-0.94), any drug (OR = 0.73, 95% CI = 0.54-0.98), marijuana (OR = 0.70, 95% CI = 0.50-0.98), and tobacco (OR = 0.83, 95% CI = 0.69-1.00) diagnoses, and lower odds of any inpatient hospitalizations (OR = 0.59, 95% CI = 0.41-0.85) compared with usual care. Negative binomial models examining number of visits among adolescents with at least one visit of that type found that those in the SBIRT group had fewer primary care (incidence rate ratio[iRR] = 0.90, p < .05) and psychiatry (iRR = 0.64, p < .01) and more addiction medicine (iRR = 1.52, p < .01) visits over 7 years compared with usual care. In posthoc analyses, we found that among Hispanic patients, those in the SBIRT group had lower odds of any substance, any drug and marijuana use disorder diagnoses compared with usual care, and among Black/African American patients, those in the SBIRT group had lower odds of alcohol use disorder diagnoses compared with usual care. Beneficial effects of adolescent SBIRT on substance use and healthcare utilization may persist into young adulthood.