Prescription medicines purchased in the U.S. under a controversial government discount program amounted to $100 billion in 2025, a 22.8% increase from the previous year, according to the Health Resources and Services Administration, which oversees the program.

Expensive medicines represented an increasing proportion of spending in the 340B Drug Discount Program, accounting for $61.9 billion, or nearly 62% of all prescription drugs purchased through the program. Nearly $8.9 billion was spent on Merck’s Keytruda immunotherapy treatment, followed by more than $4.47 billion on Biktarvy, an HIV medicine sold by Gilead Sciences.

The data mark a steady rise in sales under the 340B program, which requires drugmakers to offer discounts that are typically estimated to be 25% to 50% — but could be higher — off all outpatient drugs to hospitals and clinics that primarily serve lower-income patients.