The price you pay at the counter is not one number. It is the end of a chain that starts with the manufacturer’s list price and passes through wholesalers, pharmacy benefit managers, and your plan’s own design before it reaches you.
Every step in that chain is a chance for someone to take a margin. Most of those margins are invisible to the member and, in a traditional PBM contract, invisible to the plan sponsor too. Spread pricing, rebate retention, and undisclosed administrative fees all sit inside the gap between what a plan pays and what a pharmacy receives.
A fully disclosed model closes that gap by design. There is one source of revenue: an administrative fee the plan sponsor agrees to up front. Rebates pass through at one hundred percent. What the pharmacy is paid is what the plan is charged. When the chain is visible end to end, the price stops being a mystery and starts being a number you can audit.
That matters most for the medications people take every day. A drug that costs a member six thousand dollars a year under one contract can cost a fraction of that under another, with no change to the molecule, the manufacturer, or the dose. The difference is entirely in how the benefit is structured.