Cigna’s Express Scripts continued its lead in the U.S. pharmacy benefit manager market for the second year in a row, processing nearly one-third of all prescription claims, according to a March 30 report from the Drug Channels Institute.
The PBM handled 31% of total equivalent prescription claims last year, up from 30% in 2024. CVS Caremark, which dominated the sector until 2024, saw its share fall to 26% amid volume losses tied to major client transitions. Optum Rx, a subsidiary of UnitedHealth Group, maintained a 23% share for the second straight year.
Despite ongoing scrutiny from regulators and rising competition from smaller firms, the same three PBMs as last year still control 80% of the market.
The rankings are based on Drug Channels Institute’s analysis of total equivalent prescription claims processed across the industry.
The top PBMs by 2025 market share:
Express Scripts: 31%
CVS Caremark: 26%
Optum Rx (UnitedHealth): 23%
Humana Pharmacy Solutions: 7%
MedImpact Healthcare Systems: 5%
Prime Therapeutics: 3%
All other PBMs and cash pay: 5%
