CMS and HRSA moved to adjust 340B drug pricing mechanics and reimbursement transparency through new rules and a revised rebate model pilot. CMS proposed changes to payment rates under the 340B Drug Pricing Program beginning in calendar year 2027, citing hospital acquisition and utilization-management alignment to reduce affordability pressure. HRSA also revised the 340B Rebate Model Pilot Program, creating a voluntary pathway for manufacturers to provide 340B ceiling price through post-dispensing rebates rather than upfront discounts for selected drugs tied to the Medicare Drug Price Negotiation Program for 2026 and 2027. Together, the actions signal tighter claims-level visibility and new operational requirements for manufacturers and covered entities, with pilot participation and implementation timelines (including manufacturer submissions due Aug. 24, 2026 and pilot start in 2027) likely shaping how access and drug economics are managed.