In a lawsuit, the FTC accused Optum Rx, Caremark and Express Scripts of creating "a broken rebate system that inflated insulin drug prices, boosting PBM (prescription drug benefit managers) profits at the expense of vulnerable patients."

The FTC accused the “Big Three” pharmacy benefit managers (PBMs) — UnitedHealth Group’s Optum Rx, CVS Health’s Caremark and Cigna’s Express Scripts — of “engaging in anticompetitive and unfair rebating practices that have artificially inflated the list price of insulin drugs, impaired patients’ access to lower list price products, and shifted the cost of high insulin list prices to vulnerable patients.” Around 8 million Americans rely on insulin in the U.S., per the FTC.