The Trump administration is putting its weight behind an effort to stop drug manufacturers from changing how a safety-net drug program that disproportionately benefits rural, working-class Americans operates.

Since its creation in 1992, the 340B program — as it has come to be called — has become one of the most extensive federal drug programs, covering $66 billion in prescription drug purchases in 2023. Drug manufacturers say the program is unsustainable and flawed. Instead of functioning as a drug discount program as it has since its inception, drugmakers want it to function as a rebate program.

Healthcare providers oppose that change. They argue that a rebate is not what Congress intended when they drafted the law. Under the program, manufacturers provide prescription drugs to health clinics and hospitals at discounted prices. Those facilities — referred to as “covered entities” — can provide the drugs to under- and uninsured patients who otherwise would not be able to afford them. Alternatively, the hospitals are reimbursed by insurance carried by better-off patients, and providers use the savings on the drugs to pay for frontline medical professionals and equipment, ranging from emergency room doctors to MRI machines.

Among the entities enrolled in 340B are rural hospitals, HIV and AIDS drug assistance programs, clinics treating opioid addiction, black lung clinics, and hospitals that have a disproportionate share of Medicare, Medicaid and other low-income and uninsured patients.