Impacted: Health plan clients (Commercial and Medicare)

What you need to know

Thirteen drugs will see reduced list prices in 2026 as manufacturers respond to Average Manufacturer Price (AMP) Cap changes, shifting value from rebates to lower upfront ingredient costs. The Centers for Medicare & Medicaid Services (CMS) has also selected 10 drugs for Maximum Fair Price (MFP) negotiations, which similarly reduces rebate totals.  

Consistent with current contractual provisions, Prime intends on equitably adjusting rebate guarantees as necessary to reflect shifted value, through either a rebate guarantee restatement or applying a rebate credit to the 2026 rebate reconciliation.   

Background and impacts 

The removal of the AMP Cap in 2024 has led some manufacturers to lower upfront Wholesale Acquisition Cost (WAC) on select drugs. Lower list prices reduce rebates, shifting value from rebate payments to lower ingredient cost at the point of sale across all lines of business. This trend continues in 2026, with 13 additional drugs experiencing list price reductions related to AMP Cap. 

Rebates will continue to be paid as usual; however, affected products will generate lower rebates because their list prices have been reduced. 

AMP Cap (Commercial) 

The following figures are representative of Prime's book of business, and individual client experience may vary. The estimated impact of the 13 drugs in 2026 is a 7% shift from commercial rebates to ingredient cost savings. The total impact for the three years of the AMP Cap program is an average 11% shift from commercial rebates to ingredient cost savings (2024-2026 inclusive).   

Example  
Before AMP Cap, a drug costs $600 with a $400 rebate, resulting in $200 net cost. After AMP Cap, the net cost of the drug remains the same, but the rebate value is reduced because the value has shifted to lower upfront pricing. In this example, the drug cost decreased to $300 with a $100 rebate, resulting in the same $200 net cost.  

MFP drugs (Medicare) 

In addition, CMS has selected 10 drugs for MFP negotiations for 2026. MFP also shifts value from rebates to ingredient cost. For Medicare plans, these combined changes will result in lower rebate totals. 

Prime's standard approach is an equitable adjustment to rebate guarantees to exclude MFP drugs. The estimated combined impact of the AMP Cap and MFP on Medicare in 2026 is a 42% reduction in rebates, based on Prime’s Medicare book of business.

For a full list of drugs that have seen WAC reductions due to AMP Cap and MFP, reference this document.

Next steps

Prime will continue to monitor for drugs that may be added to AMP Cap or MFP and provide updates when available.

Questions

Please reach out to your Prime client account team representative.