The US Federal Trade Commission (FTC) sued the three largest pharmacy benefit managers (PBMs)—CVS Caremark, Cigna Express Scripts, and UnitedHealth OptumRx—for alleged anticompetitive practices that artificially inflated insulin prices.[1][2][4] These PBMs administer approximately 80% of all prescriptions in the US, and their affiliated groups of purchasing organizations allegedly abused their economic power to benefit their own rebates.[1][3][5] According to the FTC, PBMs favored more expensive insulins with higher rebates over cheaper versions, preventing patients from accessing more affordable drugs.[2][4][6] An example is Eli Lilly's Humalog insulin: in 1999, it had an average list price of $21, rising to more than $274 in 2017.[1][2][5] The FTC claims that this causes millions of diabetics to pay higher out-of-pocket costs for a vital drug.[4][5] In 2019, a quarter of insulin patients could not afford their medicine.[1] According to the FTC's statement, this rebate system has netted PBMs billions of dollars at the expense of patients.[3][6]