Between the drug company and the patient sits a supply chain that handles hundreds of billions of dollars a year and that few patients see: three wholesalers that distribute most US prescription drugs on margins of ~1%, about 60,000 pharmacies, and three pharmacy benefit managers (PBMs) that processed ~80% of US prescription claims in 2025 (Drug Channels). The physical chain moves boxes; the financial chain moves rebates, fees and "spreads" that nobody in the room fully discloses. That opacity made PBMs the most investigated intermediaries in American healthcare between 2022 and 2026: an FTC study and lawsuit, an Express Scripts settlement in February 2026, and federal PBM reform signed the same month. This section explains the physical and financial flows, how each player makes money, the vertical integration of insurers, PBMs and pharmacies, the transparency fights, and the alternative models (Cost Plus Drugs, transparent PBMs, manufacturer cash channels) trying to replace the old one.
What the study covers
- 1Overview: two chains, one prescription
- 2Wholesalers: big revenue, thin margins
- 3Pharmacies: retail, mail and specialty
- 4PBMs: what they do and how they make money
- 5Transparency fights and reform, 2018–2026
- 6Key numbers
- 7Landmark companies and cases
- 8Pitfalls
- 9How an expert thinks about it
- 10Glossary
Technical exhibits
Worked examples, checklists and case studies included with this study.
PBM Rebate and Spread Pricing Worked Example
Stylized flow of one brand prescription from WAC to net, rebate pass-through scenarios, coinsurance on list price, generic spread, and a 10,000-member employer under traditional vs transparent contracts (computed by script)
PBM Contract Diligence Checklist
What an employer or plan sponsor should ask and audit in a PBM contract