States With Substantial Increases In Buprenorphine Uptake Did So With Increased Medicaid Prescribing, 2018-24.

Multiple federal policy changes since 2018 have been intended to increase buprenorphine prescribing in response to a persistent treatment gap for opioid use disorder in the US. Anticipated national increases did not occur, but highly variable state-level trends provide important insights. We used IQVIA data to examine all-payer and per payer prescribing across states during the period 2018-24. All-payer prescriptions per 1,000 residents increased by more than 60 percent in ten states while decreasing by more than 10 percent in eight states. States expanding Medicaid during this period increased all-payer prescribing by 27.3 percent; those that had expanded earlier increased prescribing by 11.6 percent, whereas in nonexpansion states, prescribing declined by 2.1 percent. All-payer rates ranged thirty-eight-fold in 2024 (varying from 9.3 to 355.5 per 1,000; lowest quintile, 15.7 per 1,000; highest quintile, 118.6 per 1,000). Medicaid prescribing changes were key drivers of all-payer changes. In 2024, Medicaid prescribing ranged from 0.50 per 1,000 to 217.26 per 1,000, and from 3.6 percent to 66.8 percent of all-payer buprenorphine prescriptions. The self-pay proportion ranged from 0.7 percent to 30.8 percent, and this proportion was strongly associated with the Medicaid proportion. Highly disparate state-level changes suggest that federal policy impacts were mediated by state-specific factors. Medicaid's key role in driving overall prescribing highlights the public health urgency of maintaining expansions and sustaining enrollment for the single adult population.