What is the largest PBM in the US?

What is the largest PBM in the US?

They’ve traditionally been less visible to the public, but their influence has grown, with the three largest PBMs — UnitedHealth Group Inc.’s OptumRx, CVS Health Corp.’s CVS Caremark and Cigna Corp.’s Express Scripts — processing an estimated 77 percent of all prescription claims last year. Aug 26, 2021