Medicaid managed care organization service coverage and diagnosis and treatment of opioid use disorder: evidence from quasi-random auto-assignment in Kentucky.

Introduction: Opioid-related mortality continues to claim tens of thousands of American lives annually. Medicaid plays an outsized role in financing opioid use disorder (OUD) treatment, paying for almost 40% of all Americans who received OUD treatment in 2017. Methods: Using Medicaid T-MSIS Analytic Files data and a novel data set of Medicaid managed care organization (MCO) plan coverage, we examined the relationship between comprehensiveness of benefits for OUD treatment provided by Medicaid MCO plans and the likelihood of OUD diagnosis and medications for OUD (MOUD) receipt among newly enrolled Medicaid beneficiaries in Kentucky. We use two stage least squares to adjust for MCO plan choice that may be correlated with individual OUD risk or individual demand for OUD treatment. Results: Our findings show that Medicaid beneficiaries assigned to MCO plans with more comprehensive OUD benefits are more likely to be diagnosed with OUD and to receive MOUD. Conclusion: These results suggest that increasing Medicaid MCO plan coverage to include a broader array of OUD treatment services and medications may be an effective strategy for increasing both OUD diagnosis and MOUD receipt, which is crucial for combating the ongoing opioid epidemic.