Pharmacy Benefit Managers retain 20-24% of drug spending as profit through spread pricing and rebate retention, inflating costs for employers and patients

The three largest PBMs -- CVS Caremark, Express Scripts (Cigna), and OptumRx (UnitedHealth) -- control approximately 80% of the U.S. prescription drug market and profit from opaque pricing mechanisms that misalign incentives with drug affordability. Spread pricing (charging plan sponsors more than the PBM pays the pharmacy) and commercial rebate retention allow PBMs to extract 20-24% of drug spending as profit, while the drugs with the highest rebates (not the lowest net cost) get preferred formulary placement. Why it matters: approximately $350 billion in rebates flowed through the system in 2024, so PBMs are incentivized to favor high-list-price drugs that generate larger rebates rather than lower-cost alternatives, so patients with coinsurance pay a percentage of the inflated list price rather than the net price, so independent pharmacies receive below-cost reimbursement and are closing at accelerating rates (particularly in rural areas), so the drug pricing system becomes progressively more opaque and resistant to reform because PBMs profit from complexity. The structural root cause is that PBMs evolved from claims processors into vertically integrated entities that own specialty pharmacies, mail-order pharmacies, and health plans, creating self-dealing conflicts of interest that existing regulation has failed to address -- 24 states passed 33 PBM-related bills in 2024 alone, indicating widespread recognition of the problem but fragmented enforcement.