Continuity of Medications for Opioid Use Disorder in States With and Without Medicaid Prescription Cap Policies

Background: Medicaid prescription cap policies persist in 12 states; however, it is unclear how they affect the quality of opioid use disorder (OUD) treatment. Objectives: To examine the association between cap policies and the continuity in receipt of medication for OUD (MOUD) treatment in Medicaid. Methods: Using 2016–2021 T-MSIS Analytical Files data from 37 states, we identified nondual adult (18–64 y) Medicaid enrollees diagnosed with OUD who received MOUD. The exposure was the state’s Medicaid prescription cap policy status. The main outcome was a binary variable for MOUD continuity, overall and by type, defined as no treatment gap exceeding 7 consecutive days during a 180-day observation period. We estimated risk ratios for MOUD continuity using modified Poisson regression models, adjusting for individual and state-level covariates to test associations. Results: Nearly half the sample was female, and the mean age was 37 years. MOUD continuity ranged from 40.7% to 44.3% in states without cap policies and 37.5%–39.6% in cap states. Compared with enrollees in noncap states, those in cap states had a 12% higher likelihood of experiencing at least 1 MOUD treatment gap [risk ratio (RR)=1.12; 95% CI: 1.12–1.13]. These findings were consistent for buprenorphine and methadone. Factors associated with overall MOUD discontinuity included younger age, male sex, living in nonmetropolitan areas, and having 3 or more comorbidities. Conclusions: Prescription caps were associated with reduced continuity of MOUD, overall and for buprenorphine and methadone, suggesting that revising or removing these policies could improve OUD quality metrics in Medicaid.