Medicaid Buprenorphine Fills Up Tenfold as Federal Cuts Loom

Medicaid-covered prescriptions for buprenorphine, the most common medication for opioid use disorder, grew roughly tenfold over the past decade and a half — from 936,000 fills in 2010 to a peak of 9.4 million in 2021 — before easing to 8.2 million in 2025, according to an Urban Institute analysis published September 22. The report warns that the historic expansion is now at risk as federal Medicaid cuts enacted under the One Big Beautiful Bill Act begin to take effect.

A decade of growth concentrated in expansion states

The analysis, funded by the Foundation for Opioid Response Efforts and authored by health policy researcher Lisa Clemans-Cope, tracked Medicaid-covered prescription fills for three medications — buprenorphine, naltrexone, and naloxone — from 2010 through 2025 using Medicaid State Drug Utilization Data.

The growth was far from evenly distributed. States that expanded Medicaid under the Affordable Care Act before 2019 accounted for about 80 percent of all Medicaid buprenorphine fills across the entire 16-year period, with the largest increases in states carrying the heaviest opioid use disorder burdens. By 2021, an estimated 61 percent of Medicaid enrollees with opioid use disorder had gained their coverage through ACA expansions, according to KFF, and by 2023 Medicaid was financing more than half of all opioid use disorder medications nationally.

Using a benchmark of nine medication fills per treated enrollee per year, the researchers estimate that about 59 percent of Medicaid enrollees with opioid use disorder received buprenorphine in 2025 — up from roughly 36 percent in 2019. Clemans-Cope cautions that these are approximate rates, sensitive to the underlying prevalence and enrollment estimates, but says the direction is consistent with earlier research showing treatment gains concentrated in expansion states.

Wide gaps between states remain

Even after years of growth, access varies dramatically. In 2025, buprenorphine fills per 1,000 Medicaid enrollees estimated to have opioid use disorder varied roughly eleven-fold across state groups. States that expanded Medicaid between 2019 and 2023 and have lower opioid use disorder rates posted the highest fill rate of any subgroup, at 10,974 per 1,000 enrollees. States that had not expanded Medicaid by 2024 and have lower opioid use disorder rates recorded just 985 fills per 1,000 — less than one-tenth the rate.

Buprenorphine made up 57 percent of Medicaid prescriptions for opioid use disorder medications in 2022, according to the Medicaid and CHIP Payment and Access Commission, ahead of methadone at 29 percent and naltrexone at 6 percent. Buprenorphine and methadone are the two opioid-agonist medications associated with an 80 percent lower risk of overdose death.

What the federal cuts put at stake

The findings land in a policy environment moving in the opposite direction. The One Big Beautiful Bill Act is expected to strip Medicaid coverage from approximately 1.6 million people with substance use disorders, according to the Center for American Progress, and to reduce federal Medicaid spending by more than $900 billion over the next decade, according to KFF estimates. Separate Urban Institute modeling projects that the law's work requirements and six-month eligibility redeterminations for the expansion population could cut Medicaid enrollment by 4.9 million to 10.1 million people in 2028.

The stakes are amplified by Medicaid's outsized role in addiction care: the program covers nearly half of nonelderly adults with opioid use disorder. Although the law includes narrow exemptions from its requirements for people with substance use disorders, research cited in the analysis shows many eligible patients will likely struggle with the documentation needed to prove it. Even a brief loss of coverage can interrupt access to medication-assisted treatment and immediately raise the risk of fatal overdose.

The analysis also notes that in April 2026, the Substance Abuse and Mental Health Services Administration issued two Dear Colleague letters directing grantees to discuss discontinuing medication among patients receiving treatment for opioid use disorder and barring federal funds for fentanyl test strips — moves critics describe as a pullback from evidence-based practice.

A fragile decline in overdose deaths

The warning comes after three consecutive years of declining drug overdose deaths, from 2023 through 2025, including a drop of nearly 27 percent from 2023 to 2024 alone, according to CDC data. While disruptions in the illicit fentanyl supply were a major contributor, researchers say multiple factors worked together — and the expansion of Medicaid-funded treatment was a potentially important enabling one.

To protect those gains, the Urban Institute authors urge policymakers to preserve Medicaid coverage for people with opioid use disorder, maintain federal funding for SAMHSA treatment and harm-reduction programs, and encourage the remaining non-expansion states to close their treatment gaps through expansion.