Medicaid, Medicare, and commercial payers obtain the same drug through completely different mechanisms. Comparing them without knowing which is which produces nonsense.
The same molecule reaches a Medicaid enrollee, a Medicare beneficiary, and a commercially insured worker through three different pricing mechanisms. Understanding which is which prevents most of the confused comparisons in this field.
The mechanisms
Medicaid obtains statutory rebates. Manufacturers that want their drugs covered participate in a rebate program, and states also negotiate supplemental rebates. KFF notes that states receive “substantial rebates on brand drugs.” The result is that Medicaid’s net prices are generally the lowest of the three, and its published gross figures overstate its actual cost the most.
Medicare historically obtained discounts only indirectly, through Part D plans and their PBMs negotiating rebates. Since January 1, 2026 it also negotiates directly for selected drugs, producing Maximum Fair Prices for ten Part D drugs in the first cycle with a second cycle following for 2027. That mechanism covers only “high expenditure, single source drugs without generic or biosimilar competition.”
Commercial payers rely on PBM-negotiated rebates, which are confidential. Module 1 established the concentration behind that negotiation: six PBMs manage nearly 95 percent of prescriptions, vertically integrated with the largest insurers and pharmacies.
| Payer | Discount mechanism | Transparency |
|---|---|---|
| Medicaid | Statutory rebates plus state supplemental rebates | Statutory formula public, supplemental rebates not |
| Medicare Part D | Plan and PBM rebates, plus negotiated Maximum Fair Prices for selected drugs | Negotiated prices published; rebates not |
| Commercial | PBM-negotiated rebates | Confidential |
What follows
Cross-payer gross comparisons are not informative. A headline that Medicaid spends more per prescription than a commercial plan may reflect nothing but different rebate mechanisms operating below the published number.
Coverage decisions differ for structural reasons. State Medicaid programs facing budget constraints made the GLP-1 coverage decisions in the previous lesson. Medicare faces a statutory exclusion. Employers face labor market pressure. Each is responding to a different constraint, so their divergent choices are not evidence that some of them got it wrong.
A provider organization sits across all of them. An organization with Medicare, Medicaid, and commercial risk contracts is managing the same clinical decision under three different economic regimes, often without visibility into any of the net prices.
Worth remembering: this is the closing structural observation of the entire curriculum. A clinician deciding whether to prescribe a drug is making one decision. That decision lands in a Medicaid budget subject to statutory rebates, or a Part D benefit reshaped by the Inflation Reduction Act, or a self-funded employer’s claims run through a PBM its own carrier owns. The clinical question is identical and the economic consequence is completely different depending on who is covering the patient. Every course in this Academy has described one part of that machinery. Holding the whole picture, and knowing which part you are standing in, is what this curriculum was built to teach.
Key takeaways
- Medicaid uses statutory and supplemental rebates, producing generally the lowest net prices.
- Medicare uses plan and PBM rebates plus, since 2026, negotiated Maximum Fair Prices for selected single-source drugs.
- Commercial payers depend on confidential PBM-negotiated rebates in a highly concentrated market.
- Cross-payer gross comparisons strip out exactly the mechanisms that differ, so they mislead.
Sources
Check your understanding
Why are gross drug spending comparisons across Medicaid, Medicare, and commercial payers close to meaningless?
Medicaid uses statutory rebates, Medicare now uses negotiated Maximum Fair Prices for selected drugs, and commercial payers rely on confidential PBM-negotiated rebates. Gross figures strip out precisely what differs.