Objective: This study aims to determine if outpatient opioid prescriptions are associated with future SUD diagnoses and overdose in injured adolescents 5 years following hospital discharge. Summary of Background Data: Approximately, 1 in 8 adolescents are diagnosed with an SUD and 1 in 10 experience an overdose in the 5 years following injury. State laws have become more restrictive on opioid prescribing by acute care providers for treating pain, however, prescriptions from other outpatient providers are still often obtained. Methods: This was a retrospective cohort study of patients ages 12–18 admitted to 2 level I trauma centers. Demographic and clinical data contained in trauma registries were linked to a regional database containing 5 years of electronic health records and prescription data. Regression models assessed whether number of outpatient opioid prescription fills after discharge at different time points in recovery were associated with a new SUD diagnosis or overdose, while controlling for demographic and injury characteristics, and depression and posttraumatic stress disorder diagnoses. Results: We linked 669 patients (90.9%) from trauma registries to a regional health information exchange database. Each prescription opioid refill in the first 3 months after discharge increased the likelihood of new SUD diagnoses by 55% (odds ratio: 1.55, confidence interval: 1.04–2.32). Odds of overdose increased with ongoing opioid use over 2–4 years post-discharge (P = 0.016–0.025). Conclusions: Short-term outpatient opioid prescribing over the first few months of recovery had the largest effect on developing an SUD, while long-term prescription use over multiple years was associated with a future overdose.