The Health Resources and Services Administration (HRSA) July 22 issued a final rule implementing the orphan drug exclusion under the Affordable Care Act (ACA). The final rule states that new covered entities added to the 340B program under the ACA—i.e., critical access hospitals, rural referral centers, sole community hospitals, and freestanding cancer hospitals—may receive 340B discounts on orphan drugs when the drugs are used for a disease or condition outside of the indication for which the drug received its designation. Drugs designated as “orphan” are intended to treat, diagnose, or prevent rare diseases or disorders. Additional details on applicability and implementation may be found in the final rule.