Category M.
The Drug Tariff category where generic reimbursement prices are reset quarterly from manufacturer sales data. The reason generic prices move in steps.
Category M covers several hundred common generic medicines whose reimbursement prices the Department of Health and Social Care recalculates each quarter from manufacturers' actual sales data. It is the mechanism by which the NHS recovers pharmacy purchasing margin, and the reason a generic's price line looks like a staircase rather than a curve.
For anyone reading cost-per-item charts, Category M is the alternative explanation to rule out before crediting a commercial story. A step change at a quarter boundary is usually the Tariff, not the market.
Net ingredient cost (NIC) · The list price of what was dispensed, before discounts. The spend figure in open prescribing data, and a ceiling rather than a bill.
Price concessions · Temporary reimbursement increases granted when pharmacies cannot buy at the Drug Tariff price. The closest thing open data has to a shortage signal.
See it on a real molecule.
Every molecule page uses this term somewhere: in the scorecard, the charts or the honesty strip. The definitions live here; the numbers live there.