Medicaid Unwinding: Association With New and Ending Buprenorphine Treatment Episodes

Importance: Medicaid is an important source of coverage for buprenorphine treatment for opioid use disorder (OUD). The loss of Medicaid coverage through Medicaid unwinding may substantially impact individuals’ ability to initiate and continue buprenorphine, but little is known about how Medicaid unwinding is associated with buprenorphine OUD treatment. Objective: Examine the association of Medicaid unwinding overall and by magnitude of unwinding with changes in buprenorphine OUD treatment. Design, Setting, and Participants: Retrospective cohort study using 2021–2023 national retail pharmacy data on dispensed buprenorphine prescriptions. Exposure: Magnitude of Medicaid disenrollment in the 6 months after unwinding began. Main Outcome(s) and Measure(s): Average monthly change in new and ending buprenorphine treatment episodes, defined as starting buprenorphine treatment after 30 days without buprenorphine and ending after 30 days without buprenorphine. Statistical significance was assessed using 95% CI constructed from 2-sample t tests. Results: Medicaid unwinding was associated with increases in Medicaid buprenorphine episodes ending (+3.0%, 95% CI: −1.1, 7.0, n=+5350) and decreases in new Medicaid episodes (−2.6%, 95% CI: −5.3, 0.1, n=−5756). The greatest changes were in states with the greatest disenrollment (+5.5%, 95% CI: 0.8, 10.1; n=+2320 for episodes ending and −3.9%, 95% CI: −7.3, −0.6; n=−1843 for episodes starting). Changes in Medicaid-covered episodes were not offset by other payers: among all payers, we observed an increase in episodes ending (+2.7%, 95% CI: 1.9, 3.4, n=+10,300) and a negligible increase in new episodes (+0.1%, 95% CI: −0.7, 1.0, n=+570). Conclusions and Relevance: Medicaid unwinding may have resulted in substantial disruptions to buprenorphine treatment.