New OIG Guidance on Pharmaceutical Discount Arrangements: Compliance Considerations for Manufacturers and Antitrust Enforcement
On December 18, 2025, the U.S. Department of Health and Human Services Office of Inspector General (OIG) issued Advisory Opinion No. 25-11, addressing certain discount and rebate arrangements proposed by a biopharmaceutical manufacturer of vaccines. The manufacturer, whose information was redacted in OIG’s opinion, sought approval for discount structures covering three vaccines:
- Vaccine A, a messenger RNA vaccine available in frozen and pre-filled syringe formats reimbursed under Medicare Part B;
- Vaccine B, a preventive vaccine reimbursed under Medicare Part D; and
- Vaccine C, comprising two preventive vaccines reimbursed under Medicare Part B.
The opinion offers important guidance for structuring discount programs that span multiple products and Medicare reimbursement methodologies. This article assesses the key takeaways from this opinion and the implications for the broader landscape of pharmaceutical pricing and reimbursement.
Regulatory Framework: The Anti-Kickback Statute and Discount Safe Harbor
Understanding the significance of Advisory Opinion 25-11 requires familiarity with the regulatory framework governing the healthcare, pharmaceutical and medical device industries. Under the federal Anti-Kickback Statute, codified at section 1128B(b) of the Social Security Act, offering or receiving remuneration in exchange for purchasing items or services covered by federal healthcare programs (FHCPs) is prohibited. The Discount Safe Harbor, codified at 42 C.F.R. § 1001.952(h), provides protection for price reductions offered by a seller to a buyer if the discount is properly disclosed to FHCPs through customer claims or cost reports.
The definition of “discount” under the Safe Harbor—that is, a reduction in the amount a buyer is charged for an item purchased directly or indirectly based on an arms-length transaction—is critical to understanding which arrangements proposed by the Requestor qualify for protection. Importantly, the Safe Harbor explicitly excludes from this definition “[s]upplying one good or service without charge or at a reduced charge to induce the purchase of a different good or service, unless the goods and services are reimbursed by the same Federal health care program using the same methodology.”
The Proposed Discount Framework
The manufacturer’s proposed arrangements consisted of four distinct categories:
- Category 1: Upfront Discounts - The manufacturer offers discounts to customers at the time of purchase based solely on a percentage off the Vaccine A list price or contract price through flat percentage discounts, prompt-payment discounts, and supply reservation discounts.
- Category 2: Upfront Discounts with Purchase Requirements - The manufacturer offers upfront discounts tied to customers achieving specified market share or volume thresholds during prior measurement periods.
- Category 3: Bundled Upfront Discounts with Purchase Requirements - Discounts are offered contingent on achieving certain purchase requirements across a bundle of products, including products reimbursed under the same or different FHCP methodologies.
- Category 4: Bundled Rebates - The manufacturer pays rebates based on pre-specified percentages and terms after the purchase and contingent on achieving certain purchase requirements.
OIG’s Analysis and Risk Assessment
The OIG assessed each discount arrangement to determine whether it met the criteria for a discount protected by the Discount Safe Harbor.
Categories 1 and 2: Protected Discounts
The OIG concluded that the upfront discounts in Categories 1 and 2 meet the definition of a protected discount under the Discount Safe Harbor. Critically, the OIG noted that if buyers are required to perform any promotional or other services to qualify for these discounts, it would reach a different conclusion. These arrangements present low risk of fraud and abuse because:
- Discounts apply to a single product
- Price reductions are transparent and disclosed at the point of sale
- Customers can accurately report costs to Medicare
Categories 3 and 4: Outside Safe Harbor Protection
The OIG opined that discounts offered under Categories 3 and 4 do not satisfy the definition of a discount because the vaccines included in the bundle could be reimbursed under different methodologies or Medicare systems. The Safe Harbor definition explicitly excludes arrangements that supply one good at a reduced charge to induce purchase of a different good; unless both are “reimbursed by the same Federal health care program using the same methodology.”
The OIG has previously expressed concerns that bundled discounts—where the reduced price on one item induces purchases of other products fully paid for by the FHCPs—shift or distort the true costs reported to FHCPs. It argued that when a manufacturer offers a discount on a Part B vaccine contingent on purchasing a Part D vaccine, the actual acquisition cost of each product becomes obscured, potentially leading to improper reimbursement calculations.
Despite arguing that Categories 3 and 4 fall outside the Discount Safe Harbor, the OIG noted that the “upfront” bundled discounts present low risk of fraud and abuse because customers are aware of all pricing adjustments prior to the initial purchase. The OIG viewed that this transparency allows customers to accurately calculate and report costs to Medicare, mitigating the cost-shifting concerns that typically accompany bundled arrangements.
Key Takeaways for Structuring Compliant Discount Arrangements and What to Watch Out For
What Receives Safe Harbor Protection
Advisory Opinion 25-11 confirms that several common discount structures receive Safe Harbor protection or present low risk under the Anti-Kickback Statute. Price reductions can meet the definition of a discount even when contingent on other factors, including prompt-payment discounts, supply reservation discounts, and market share or volume purchase requirements. Bundled discounts based on volume or market share targets are also protected, as long as the items or services are reimbursed under the same methodology—with OIG clarifying that Medicare Parts B and D each constitute unified reimbursement methodologies.
Low-Risk Factors for Bundled Upfront Discounts
For bundled discounts that fall outside the Safe Harbor—such as those spanning different Medicare parts—OIG identified several factors that it believes reduce risk of fraud and abuse. These include discounts that are readily attributable to each separately billable item and arrangements where each Medicare reimbursement system benefits equally. Additionally, bundles where all items are discounted rather than offering a deep discount on one product to induce purchases of another, and situations where each product has at least one competing product with a similar list price are considered low risk.
Important Warnings and Unresolved Questions
Although this advisory opinion only applies to the specific facts presented, it offers valuable insights into how OIG views certain discount and rebate structures. Notably, the OIG issued warnings about discount arrangements that it believes could diverge from the Safe Harbor. The opinion emphasizes that discounts contingent on providing services, including promotional activities, marketing, or switching patients from one product to another—not only fall outside the Safe Harbor but likely would not be considered sufficiently low risk for a favorable opinion. Manufacturers should ensure that discount agreements do not require customers to perform such services as a condition of earning the discount to avoid potentially facing enforcement action.
The opinion also introduces flexibility for adjusting rebate terms mid-contract to meet competition, provided the possibility of adjustment is disclosed to customers upfront.[1] However, the boundaries of this flexibility remain somewhat unclear—particularly regarding what constitutes acceptable justifications for changes and whether adjustments can apply retroactively.
Conclusion
Advisory Opinion 25-11 offers manufacturers clearer pathways for structuring vaccine discount programs, while underscoring the need for transparency in pricing arrangements. The opinion confirms that upfront discounts, volume-based incentives, and certain bundled arrangements can comply with the Discount Safe Harbor when properly structured and disclosed. At the same time, it signals areas where manufacturers should exercise caution—particularly regarding service requirements and bundled products with different reimbursement methodologies.
What makes this opinion particularly noteworthy is its recognition that arrangements falling outside the Safe Harbor’s technical requirements may still present sufficiently low risk to warrant OIG approval. However, the opinion’s silence on the statutory discount exception and ambiguity around mid-contract rebate adjustments suggest that manufacturers will need to continue evaluating their arrangements on a case-by-case basis. As Anti-Kickback Statute enforcement remains a priority for regulators, manufacturers should use this opinion as an opportunity to review their existing discount structures and ensure they align with OIG’s evolving guidance.
CITATIONS
[1] https://oig.hhs.gov/documents/advisory-opinions/11424/AO-25-11.pdf
[2] https://www.ssa.gov/OP_Home/ssact/title11/1128B.htm
Experts
Rajshri SureshManaging Consultant