The U.S. Department of Labor finalized a broad rule requiring pharmacy benefit managers to disclose detailed information about their compensation, including rebates and so-called spread payments, to self-insured employer clients. Regulators estimate the rule could lower drug costs by $22 billion over a decade. The final regulation takes effect in July 2027 and requires PBMs to provide the information when negotiating or renewing contracts and then every six months. Employers can audit the disclosures once annually, and the rule includes potential penalties and the possibility of contract invalidation for noncompliance. The final rule reflects years of criticism that PBMs operate with opaque fee structures. Industry stakeholders have argued PBMs deliver savings through contracting and formulary management, while employer groups have pushed for transparency to validate whether savings are being passed through to workers and plan participants.