[yold__]

> Then they start issuing rebates instead of discounts?

They already do, and it's a huge amount of money. It's how they keep prices opaque. There is a list price (retail price), the pharmacy dispenses the drug, and gets reimbursed a variable amount from the insurance company (called the reimbursement price), usually about 50% of the list price. Then, the insurance company gets a kick-back from the drug manufacturer (usually for non-generic drugs). Medicare also gets these kick-backs, and they stopped disclosing the actual amount around 2016.