From 2017 to 2022, the companies marked up prices at their pharmacies by hundreds or thousands of percent, netting them $7.3 billion in revenue.

The nation's three largest pharmacy benefit managers have significantly marked up the prices of certain medicines, including for heart disease, cancer and HIV, at their affiliated pharmacies, the U.S.

In the debate over the high cost of prescription drugs, pharmacy benefit managers are hotly contested. PBMs, the middlemen in many prescription drug transa