A breakdown of PBM market share, by estimated total equivalent prescription claims managed in 2021:
CVS Caremark: 33 percent
Express Scripts: 26 percent
OptumRx (UnitedHealth): 21 percent
Humana Pharmacy Solutions: 8 percent
MedImpact Healthcare Systems: 4 percent
Prime Therapeutics: 4 percent
All other PBMs and cash pay: 4 percent
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