Medicaid Patients' Access to Opioid Treatment Medications Surged Nationwide, RTI Study Finds

Access to medications for opioid use disorder increased substantially among Medicaid beneficiaries across nearly every U.S. state between 2019 and 2023, according to a new study led by RTI International and published in JAMA Network Open. The findings suggest that expanded treatment access may be contributing to the national decline in opioid overdose deaths that began in 2023.

The research analyzed data covering more than 126 million annual Medicaid enrollment records from 47 states and the District of Columbia. Using the "Cascade of Care" framework—which tracks patients through stages from diagnosis to sustained treatment and outcomes—the study examined four key metrics: the percentage of patients diagnosed with OUD, the percentage receiving medications for opioid use disorder (MOUD), the percentage continuing MOUD for at least 180 days, and OUD-related hospitalizations and emergency department visits.

Treatment Access Improved While Diagnosis Rates Declined

The researchers documented a notable shift in the landscape of opioid use disorder treatment within Medicaid populations. The percentage of beneficiaries diagnosed with OUD declined from 4.2% in 2019 to 3.6% in 2023, with 34 states seeing decreases and only 14 states experiencing increases.

During the same period, the percentage of patients with OUD who received MOUD increased from 60.0% to 69.1%—a significant gain that occurred in 45 states while only three states saw declines. This improvement in treatment access represents one of the most substantial expansions of medication-assisted treatment coverage in the program's history.

"The increase in individuals receiving effective treatment for opioid use disorders may have contributed to the national decline in opioid overdose deaths, which began in 2023," said Tami Mark, Ph.D., a Distinguished Fellow at RTI and coauthor of the study. "Prior studies show that medications for opioid use disorder can cut the risk of dying in half."

Continuity of Care Remains a Challenge

Despite the encouraging gains in treatment initiation, the study revealed persistent challenges in maintaining long-term engagement. The percentage of patients who continued MOUD for at least 180 days fell from 62.6% to 57.7%, declining in 29 states and increasing in only 19 states.

This drop in treatment retention highlights a critical gap in the care continuum. While more patients are starting evidence-based treatment, keeping them engaged over the six-month period associated with optimal outcomes remains difficult. The reasons likely include fragmented care systems, insurance churn as beneficiaries cycle on and off Medicaid, workforce shortages in addiction medicine, and the logistical barriers of daily or weekly medication requirements.

OUD-related hospitalizations and emergency department visits showed mixed results. The percentage of Medicaid beneficiaries diagnosed with OUD who had acute care encounters declined slightly from 10.9% to 10.6%, but this improvement was uneven—occurring in 17 states while 31 states saw increases.

State Variation Reveals Opportunities for Learning

"The state-level variation we observed shows that progress is not evenly distributed," said William Dowd, Ph.D., a research economist at RTI and coauthor of the study. "Some states made gains across multiple measures, while others struggled to keep patients engaged in treatment, highlighting opportunities to learn from approaches that appear to support longer treatment duration."

The uneven geographic distribution of progress suggests that state-specific policies and implementation strategies matter significantly. States that expanded Medicaid under the Affordable Care Act, streamlined prior authorization requirements for buprenorphine, invested in peer recovery support services, and integrated addiction treatment into primary care settings appear to have achieved better outcomes.

Conversely, states with more restrictive formulary policies, limited provider networks, and inadequate care coordination infrastructure showed less improvement or declines in certain metrics.

Policy Context and Future Directions

The study was supported by the National Institutes of Health HEAL Initiative and used national Medicaid claims data from 2018 through 2023. The timing of the data collection captures a period of significant policy change, including the elimination of the X-waiver requirement for buprenorphine prescribing in 2023, expanded telehealth access for addiction treatment during and after the COVID-19 pandemic, and increased federal funding for state opioid response grants.

The authors emphasized that future research is needed to better understand the factors driving state-level differences and to identify strategies that improve long-term treatment engagement. With Medicaid serving as the largest payer for addiction treatment in the United States, optimizing the program's ability to initiate and sustain MOUD represents one of the most powerful levers for reducing overdose mortality.

The findings arrive as policymakers debate the future of Medicaid funding and the potential impact of work requirements, block grants, and other restructuring proposals. The study provides evidence that Medicaid can be an effective vehicle for expanding access to life-saving addiction treatment—provided that benefits are designed to support both treatment initiation and continuity of care.

For the 1.6 million Americans with opioid use disorder who rely on Medicaid for healthcare coverage, the study offers grounds for cautious optimism. More people are getting the medications that reduce overdose risk by half. The challenge now is ensuring they can stay in treatment long enough to achieve stable recovery.