Pharmacy benefit managers – the middlemen who negotiate drug prices between insurers, drugmakers, and pharmacies – are back in Congress’s crosshairs, and this time the scrutiny carries real legislative weight. A bipartisan coalition of lawmakers is pushing to restructure how these firms operate, with antitrust enforcement at the center of the debate.
The Business Model Under Examination
PBMs emerged decades ago as administrative tools to help insurers manage drug spending. Over time, three companies – CVS Caremark, Express Scripts, and OptumRx – consolidated their grip on the market to the point where they collectively process the majority of prescription claims in the United States. That concentration of power is what has drawn antitrust attention from both sides of the aisle, which is rare enough in Washington to signal that something has genuinely shifted in the political calculus around healthcare pricing.
The core complaint against PBMs is structural. They simultaneously negotiate rebates from drugmakers, set reimbursement rates for pharmacies, and design the formularies that determine which drugs patients can access at what cost. Each of those functions generates revenue, and critics argue the opacity between them allows PBMs to extract margin at every layer of the supply chain without any single regulator seeing the full picture. Independent pharmacies have been particularly vocal, arguing that reimbursement rates set by PBMs often fall below the actual cost of dispensing a drug.
Congressional hearings have spotlighted the practice of “spread pricing,” where a PBM charges an insurer more for a drug than it pays the pharmacy, pocketing the difference. Several states have already moved to ban or limit spread pricing in Medicaid programs, and federal lawmakers are now considering whether that prohibition should extend to commercial markets. The Federal Trade Commission opened an investigation into PBM practices in 2022, and a staff report released last year described a business model the agency characterized as raising costs while restricting competition.
The FTC’s findings noted that PBMs have increasingly steered patients toward pharmacies they own outright – a vertical integration strategy that independent drugstores say amounts to a captive referral system. When a PBM controls both the routing of prescriptions and the pharmacy receiving them, the incentive to offer competitive reimbursements to outside pharmacies collapses. That is the specific conflict of interest lawmakers are now trying to address through legislation.
What Congress Is Actually Proposing
Several bills are moving through committee that would require PBMs to pass 100 percent of rebates received from drug manufacturers directly to health plans and patients at the point of sale, rather than retaining a portion as profit. The logic is straightforward: rebates are currently paid by drugmakers as a condition of favorable formulary placement, and the value of that negotiation should flow to the patient whose insurance premium funds the system, not sit in a PBM’s margin. Whether that mechanism actually lowers out-of-pocket costs or simply enriches insurers is a live debate, and the legislation does not fully resolve it.
A separate legislative track targets the conflict of interest in pharmacy ownership directly. Proposals for “PBM transparency” would require disclosure of exactly how much a PBM pays its affiliated pharmacy versus what it would pay an independent competitor for the same prescription. Proponents argue that sunlight alone would constrain the most egregious forms of self-dealing, because plan sponsors – large employers and union health funds, primarily – would demand renegotiation the moment they could see the spread in black and white.
The antitrust angle is sharper and more contested. Some legislators want the FTC to apply structural remedies, forcing the largest PBMs to divest their pharmacy holdings. That would be an aggressive intervention, and the industry is lobbying heavily against it. PBMs argue that integration with pharmacies and insurers produces administrative efficiencies that reduce costs overall. The counterargument is that those efficiency claims have never been independently verified, and the market structure that produced them also produced a system where drug list prices have risen consistently for two decades.
Bipartisan support for PBM reform is genuine but fragile. Conservative lawmakers are drawn to the competition argument – concentrated markets produce bad outcomes, and breaking up vertically integrated firms is a classically Republican antitrust instinct when applied to media or tech companies. Progressive members focus more on patient access and out-of-pocket costs. Those two coalitions agree on the diagnosis but diverge on the remedy, which is why comprehensive legislation has stalled in previous sessions and may again.
Independent pharmacy groups have been the most consistent and well-organized lobbying force for reform. Their argument is grounded in specific financial reality: when PBM reimbursement rates are set below cost for generic drugs – a common practice that the FTC documented in its report – independent pharmacies are effectively being paid to lose money on every transaction. Many have closed, particularly in rural areas where chain pharmacy presence is limited. That dynamic has turned PBM reform into a healthcare access issue, not just a pricing debate, which broadens the political constituency for action.
What Enforcement Would Actually Look Like
Antitrust enforcement against PBMs is complicated by the fact that their market power operates through contracts rather than overt price-fixing. A traditional monopoly case requires showing that a single firm controls a defined market and uses that control to harm consumers. PBM market power is more diffuse – it works through information asymmetry, contractual lock-in, and the cumulative effect of thousands of individual reimbursement decisions that no single pharmacy can effectively challenge. Building an antitrust case on that foundation requires the FTC to develop legal theories it has not fully tested in court.
The most direct path to reform may be regulatory rather than judicial – new rules requiring transparency in reimbursement calculations, restrictions on spread pricing in federal programs, and mandatory disclosure of affiliated pharmacy transactions. Those measures would not break up the largest PBMs, but they would constrain the specific practices generating the most documented harm. The harder question is whether Congress will pass legislation that actually compels disclosure before the next election cycle resets the agenda entirely, or whether PBM reform joins the long list of healthcare pricing issues that generate hearings without producing enforceable law.
