The mechanism. Since 1992, the 340B program has forced drugmakers to sell outpatient drugs to safety-net hospitals and their contract pharmacies at steep, mandatory discounts — applied upfront, at the point of sale. Manufacturers have spent years arguing that model invites duplicate discounts and diversion they can't police, and want to flip it: charge full price, then send a rebate later, after submitting claims data that lets them verify each purchase. HRSA approved eight manufacturer rebate pilots effective January 1, 2026, covering roughly the ten drugs selected for Medicare's first round of price negotiations. Hospitals sued immediately. On February 10, 2026, the U.S. District Court for the District of Maine (American Hospital Association v. Kennedy) vacated the entire pilot and sent it back to HRSA for a do-over. HRSA didn't fold — on February 27 it floated expanding the rebate concept to 13 manufacturers, with an RFI comment window that ran to April 20. The legal question — does HRSA have standalone authority to bless rebates, or does that require Congress — is still unresolved, which means this is a live, multi-quarter catalyst, not a settled outcome.