Lawmakers on both the left and right are increasingly blaming pharmacy benefit managers (PBMs) — the intermediaries that negotiate prescription drug prices between manufacturers, insurers, and pharmacies — for rising healthcare costs. Last month, a bipartisan group of legislators reintroduced the Patients Before Monopolies Act, which would prohibit companies that own PBMs from also owning retail pharmacies.

Supporters of the legislation argue that vertical integration between PBMs and pharmacies is inherently anti-competitive and contributes to higher prices. But this reflects a familiar antitrust mistake: treating integration as evidence of market failure rather than recognizing the efficiencies it can create.