The U.S. Department of Labor finalized a rule requiring pharmacy benefit managers to disclose detailed information on compensation to self-insured employer clients. The rule is designed to increase transparency into payments that PBMs receive from drugmakers and pharmacies, as well as rebate and spread structures. Regulators estimate the policy could lower drug costs for employers and workers by $22 billion over a decade. The rule takes effect July 2027 and includes recurring disclosure obligations during contract negotiations and on a six-month cadence, with annual employer audit rights. PBMs and industry groups have opposed the measure, arguing it disrupts a savings model and increases compliance burdens. Employers and policymakers have supported the approach, citing difficulty determining whether PBMs act as cost stewards given complex, opaque arrangements. The final rule creates potential contract consequences for noncompliance, including penalties and possible contract invalidation.