Your plan pays one price. The pharmacy gets less. The PBM keeps the gap. That's spread pricing. Most of the people paying for it have never heard the term, and the companies doing it would like to keep it that way. Two Prices, One Prescription A PBM, pharmacy benefit manager, is the middleman that runs drug coverage for insurers and employers. The big three are CVS Caremark, Express Scripts and OptumRx. When you fill a prescription with insurance, two separate transactions ha