The U.S. Department of Labor finalized a rule requiring pharmacy benefit managers to disclose extensive compensation information to self-insured employer clients, a change regulators say is designed to reduce drug costs by improving contract transparency. Under the rule, PBMs must report data tied to payments from drugmakers, pharmacies and other supply-chain entities, including rebates and “spread” payments—when the plan pays more than the PBM reimburses a pharmacy. The disclosures begin with contract negotiations or renewals and then continue on a recurring basis every six months. Employers will be able to audit disclosures once a year, and regulators set the effective date for July 2027. The rule also creates potential penalties and contract consequences for noncompliance, including possible invalidation of an agreement. The DOL action reflected strong employer and policymaker support while PBMs opposed the change, citing fears of regulatory intrusion into compensation practices.