Most supply chain directors can tell you their GPO tier. Very few can tell you what percentage of their purchase orders actually price at that tier.
According to Vizient's April 2026 procurement analysis, only 61% of purchase orders across health system procurement are issued at the correct contract price. That means roughly 4 in 10 orders go out wrong before a vendor ships anything, before an invoice is generated, before finance flags a discrepancy. The contract says one thing. The purchase order says another. Nobody catches it in real time.
The same analysis found that more than 30% of item file attributes contain errors affecting contract alignment and reporting accuracy. The product data sitting in your item master does not match your GPO contract, and your system is pricing off a record that was wrong before you logged in this morning.
Why it matters
GPO membership is sold on aggregate savings. The marketed number, whether 10% or 18% below market, assumes compliant ordering at every transaction. When 39% of orders miss contract price, realized savings drop without anyone catching it until the quarterly compliance report lands. By then, three months of orders have already gone through at the wrong price.
For a health system with $200 million in annual GPO-contracted spend, that miss rate does not need to be large per order to become material by year end.
By the numbers
61%: share of purchase orders issued at correct contract price (Vizient, April 2026)
30%+: share of item file attributes containing errors affecting contract alignment (Vizient, April 2026)
52%: share of purchase orders still placed manually across provider organizations (Vizient, April 2026)
33%+: share of provider invoices still handled manually (Vizient, April 2026)
3 to 5%: estimated total supply chain spend lost to procure-to-pay inefficiencies without a well-functioning process (Vizient, April 2026)
Between the lines
There is a structural reason this happens at scale. GPO contracts are negotiated at the tier level, but purchase orders are generated at the item level inside an ERP. When vendors update NDCs, repackage products, or substitute a SKU, the item file in the health system's system does not automatically update. The contract updates. The vendor catalog updates. The internal file lags. The ERP keeps pricing off the old record.
Vizient's own data makes this harder to ignore: the purchase order and invoice often match each other, which creates a false sense of alignment. Both numbers can be wrong while appearing internally consistent. Finance sees a clean match. Supply chain sees a confirmed PO. Nobody sees that both figures diverged from the contracted rate three SKU updates ago.
What to do with this
Pull your off-contract spend report from your GPO portal this week, not the savings summary, the compliance detail. Look at what share of orders in the last 90 days priced at tier versus at list or off-contract. If your system cannot generate that report in under 20 minutes, the data infrastructure gap is the problem to solve first.
The contract is not where you are losing money. The execution layer is.