CMS Launches 340B Data Repository Test for IRA Rebate Calculations

The Centers for Medicare & Medicaid Services (CMS) is taking a key step in implementing the Inflation Reduction Act's drug pricing reforms, announcing a voluntary testing period for a new 340B claims data repository starting October 1, 2026. The repository is designed to identify drug units purchased under the 340B program so they can be excluded from Part D inflation rebate calculations, a central feature of the IRA. Separately, the White House announced that all 50 states and several territories will participate in the new 'Generous' payment model. These developments create significant operational and compliance considerations for pharmaceutical manufacturers and 340B covered entities. Counsel should advise clients on the strategic implications of participating in the voluntary data repository test, as its design and outcomes may shape future mandatory requirements. Related legal challenges, including ongoing litigation over the 340B 'patient' definition and manufacturers' suits against state-level 340B laws, continue to create uncertainty and should be monitored closely.