In the United States, a pharmacy benefit manager (PBM) is a third-party administrator of prescription drug programs for commercial health plans, self-insured employer plans, Medicare Part D plans, the Federal Employees Health Benefits Program, and state government employee plans. According to the American Pharmacists Association, "PBMs are primarily responsible for developing and maintaining the formulary, contracting with pharmacies, negotiating discounts and rebates with drug manufacturers, and processing and paying prescription drug claims." PBMs operate inside of integrated healthcare systems (e.g., Kaiser Permanente or Veterans Health Administration), as part of retail pharmacies (e.g., CVS Pharmacy or Rite-Aid), and as part of insurance companies (e.g., UnitedHealth Group).