GoodRx is not a Pharmacy Benefit Manager (PBM) actually. A PBM negotiates prices with pharmacies to include them in their network, GoodRx does not do that to my knowledge. Instead, GoodRx offers a service that allows users to compare different coupon and membership prices so that people can chose the best available price/pharmacy combination.
They do it by taking up the role of a PBM. This is for some other discounter, but you get the idea, they process the prescription using GoodRx's system:
