Pharmacy Benefit Managers
Pharmacy Benefit Managers (PBMs) sit between drug manufacturers and the rest of the supply chain. They were created to negotiate lower drug prices — but their incentive structure, built on rebates that behave like kickbacks, often pushes prices the other way. Here's how it works and why it matters.
A Pharmacy Benefit Manager is a third-party company that administers prescription drug benefits for health insurers and employers. PBMs decide which drugs are covered (the "formulary"), negotiate prices with manufacturers, and reimburse pharmacies.
In theory, that negotiation should lower costs. In practice, PBMs are paid through rebates — payments from manufacturers that are effectively kickbacks for formulary placement — and those rebates are structured in a way that rewards higher list prices.
Where the money goes
The rebate loop: manufacturers pay PBMs to get on the formulary, and patients pay based on the inflated list price.
Drug Manufacturer
Sets the "list price" (WAC)
PBM
Negotiates formulary placement
Health Plan / Insurer
Pays net cost after rebates
Pharmacy
Dispenses the drug
Patient
Pays copay based on list price
The rebate loop: Manufacturers pay PBMs "rebates" (effectively kickbacks) to win favorable formulary placement. The bigger the list price, the bigger the rebate the PBM can extract — so manufacturers have an incentive to raise list prices, and PBMs profit from the spread.
Three companies, ~80% of the market
The U.S. PBM market is dominated by three companies affiliated with the largest insurers and pharmacy chains.
CVS Caremark
~35%
of U.S. Rx spending
Express Scripts
~24%
of U.S. Rx spending
OptumRx
~21%
of U.S. Rx spending
The problem with kickbacks
Rebates tied to list price
PBMs negotiate rebates as a percentage of a drug's list price. A higher list price means a bigger rebate — so manufacturers are rewarded for raising prices, not lowering them.
Rebates rarely reach patients
Rebates flow back to the PBM and (sometimes) the health plan. Patients' copays and coinsurance are typically calculated from the inflated list price, not the net price after rebates.
Spread pricing
PBMs often charge health plans more than they reimburse pharmacies, pocketing the difference. The plan and the patient never see the real cost of the drug.
Concentrated market power
Three PBMs control roughly 80% of U.S. prescription drug spending. That concentration gives them enormous leverage over which drugs patients can access and at what cost.
Why this matters for patients
Because rebates are a percentage of list price, manufacturers have a structural reason to keep list prices high — and PBMs have a structural reason to let them. The patient, meanwhile, pays a copay or coinsurance calculated from that inflated list price, not the discounted net price the PBM actually negotiated.
The result is a system where the "middleman" profits from high prices, the manufacturer is rewarded for raising them, and the patient — the one actually taking the medication — often never sees the savings that were supposedly negotiated on their behalf.
Disclaimer: For educational and informational purposes only. This dashboard aggregates publicly available data from IRS Form 990 filings and third-party sources; figures may be incomplete, estimated, or out of date. Nothing here constitutes legal, financial, tax, or medical advice, or an endorsement or judgment of any organization or individual. Always verify with official filings and qualified professionals before relying on any figure.