Does PBM Market Share Vary by Payer Type?
A paper by Qato et al. (2024) quantifies the degree of of pharmacy benefit manager (PBM) market concentration. Across all payer types, the PBM market was highly concentrated, with an HHI [Herfindahl Hirschman Index (HHI)] of 1972…the HHI was lowest in commercial insurance (1940), with 90 PBM participants, and highest in Medicare Part D (2399),…