Spread pricing is when a pharmacy benefit manager charges the plan sponsor one price for a prescription and reimburses the pharmacy a lower price, retaining the difference as profit. The spread can range from a few cents per generic claim to hundreds of dollars per specialty claim. It is opaque by design and represents one of the largest hidden cost drivers in U.S. pharmacy benefits.
In 2018, an Ohio Medicaid audit identified $244 million in PBM spread pricing in a single state in a single year, across just two PBMs and a population of roughly 4 million covered lives. Extrapolated nationally, the scale of spread pricing in private and public pharmacy benefit programs runs into the multi-billions annually.
Spread pricing in one paragraph
A PBM negotiates one price with the pharmacy and a different, higher, price with the plan sponsor. The plan is billed the higher price. The pharmacy is reimbursed the lower price. The PBM keeps the difference, which is called the spread. The plan sponsor typically doesn't see the spread because the PBM only reports plan-paid amounts, not pharmacy-paid amounts. Without claim-level audit of both numbers, the spread is invisible.
How spread is hidden in PBM contracts
Spread pricing isn't usually called "spread pricing" in the contract. It's hidden through specific contract language patterns:
1. Asymmetric pricing definitions. The contract specifies a discount methodology for plan billing but doesn't specify the pharmacy reimbursement methodology. The pharmacy reimbursement is set separately by the PBM's MAC list, which the PBM controls. The two prices float independently.
2. MAC list discretion. Generic drugs are reimbursed to pharmacies at MAC. The plan is billed at AWP-minus-discount. When the PBM keeps MAC low and AWP-minus-discount high, the spread widens.
3. Specialty channel arbitrage. Specialty drugs are particularly susceptible because the prices are high, the discounts are deep, and the network is narrow. A specialty drug with AWP of $20,000 might have a pharmacy reimbursement of AWP minus 22% ($15,600) and a plan billing of AWP minus 18% ($16,400). The $800 spread per claim adds up fast.
4. Brand-vs-generic classification. Some drugs can be classified either way. A drug classified as Brand for plan billing but as Generic for pharmacy reimbursement creates a structural spread.
5. Bundled service pricing. Some PBM contracts bundle multiple services into a single "spread allowance" that's not transparently broken out.
Real-world examples
Generic statin (atorvastatin 40mg, 30-day supply):
- Pharmacy acquisition cost: $4.50
- Pharmacy reimbursement (MAC): $7.20
- Plan billed (AWP minus 87%): $22.40
- Per-claim spread: $15.20
- On 50,000 claims/year: $760,000
Brand maintenance drug (Eliquis 5mg, 30-day supply):
- Pharmacy acquisition cost: $480
- Pharmacy reimbursement (AWP minus 21%): $510
- Plan billed (AWP minus 16%): $542
- Per-claim spread: $32
- On 3,000 claims/year: $96,000
Specialty oncology drug (composite example, 30-day supply):
- Pharmacy acquisition cost: $14,200
- Pharmacy reimbursement (AWP minus 22%): $15,600
- Plan billed (AWP minus 18%): $16,400
- Per-claim spread: $800
- On 80 claims/year: $64,000
A plan with $5M in annual pharmacy spend might be losing $250K–$500K to spread without ever seeing it on a single invoice.
The Ohio Medicaid case study
In 2018, Ohio commissioned an independent audit of the spread pricing happening in its Medicaid managed-care pharmacy program. The audit found that two PBMs, CVS Caremark and OptumRx, collectively earned $244 million in spread pricing on Ohio Medicaid claims in a 12-month period, representing 31% of Ohio Medicaid's total pharmacy spend during that window.
The Ohio findings led directly to multiple states launching their own PBM spread audits, several state Medicaid programs moving to pass-through PBM contracts, and the FTC opening an investigation into PBM practices in 2022 that produced an Interim Staff Report in July 2024.
The FTC 2024 Interim Staff Report
In July 2024, the U.S. Federal Trade Commission published its Interim Staff Report on Pharmacy Benefit Managers. The report's findings on spread pricing were direct:
- The Big 3 PBMs (CVS Caremark, Express Scripts, OptumRx) collectively control over 80% of U.S. prescription claims
- Spread pricing is "a fundamentally opaque practice that benefits PBMs at the expense of plan sponsors and patients"
- Vertical integration between PBMs, insurers, retail pharmacies, and specialty pharmacies "raises serious concerns about anticompetitive conduct and market power"
- Independent pharmacies receive significantly lower reimbursement than PBM-owned pharmacies for the same drug
The directional message is clear: spread pricing is on the regulator's radar, and the era of unrestrained spread is likely ending.
How to detect spread in your own claims data
A plan sponsor can detect spread without subpoena power. The methodology requires three data sources:
1. Your claims file. What did the plan pay per claim?
2. NADAC benchmark. The National Average Drug Acquisition Cost, published weekly by CMS, is the average price pharmacies actually pay for drugs. It's a public dataset.
3. Your contract's pricing methodology. The AWP discount, dispensing fee, and rebate methodology that the contract specifies.
The audit then compares the plan-paid price against NADAC. For each generic claim, if plan-paid is meaningfully above NADAC plus a reasonable dispensing fee, spread is likely present.
How to eliminate spread going forward
Three options, in order of effectiveness:
1. Switch to a pass-through PBM. Transparent PBMs (Navitus, Capital Rx, RxBenefits, SmithRx, MaxorPlus) pass 100% of pharmacy-paid amounts through to the plan, with only a transparent admin fee. No spread by design.
2. Renegotiate the existing contract for pass-through pricing. Some traditional PBMs will offer pass-through terms at renewal if pushed.
3. Carve out specialty. Specialty drugs concentrate spread. Moving specialty to a transparent specialty pharmacy or a coalition arrangement can recover most of the savings even if retail stays with the incumbent PBM.
For most plans, option 1, a full switch to a pass-through PBM, produces the largest savings.
The takeaway
Spread pricing is the largest hidden cost in most pharmacy benefit programs. It's structural, it's opaque, and it's increasingly under regulatory scrutiny. Plan sponsors who audit for spread find it. Plan sponsors who don't audit, never see it.