Beyond Overdose Prevention: Naloxone Coprescription Laws and the Path to Treatment

Over one-third of U.S. states have enacted naloxone coprescription laws, requiring physicians to prescribe or offer naloxone alongside high-risk opioids. Using Medicare Part D data, the Treatment Episode Data Set, and a difference-in-differences design, we study how these laws affect naloxone access, broader prescription behavior, and treatment engagement. Coprescription laws increased naloxone prescribing by 275%, with effects twice as large in states requiring prescriptions as in those requiring only offers. We find no evidence of increased opioid or benzodiazepine prescribing, countering moral hazard concerns that broader naloxone access might encourage riskier opioid use. Instead, we document significant increases in prescribing of medications for opioid use disorder (MOUD) and gains in opioid use disorder treatment admissions, primarily in deliberate treatment-seeking settings. These results suggest that coprescription laws may have broader benefits beyond overdose prevention.