On February 18, 2025, the First Circuit joined the Sixth and Eighth Circuits in adopting a “but for” causation standard in cases involving per se liability under the federal Anti-Kickback Statute (AKS) and the False Claims Act (FCA). In U.S. v. Regeneron Pharmaceuticals, the First Circuit held that for an AKS violation to automatically result in FCA liability, the government must show that the false claims would not have been submitted in the absence of the unlawful kickback scheme. The decision is the latest salvo in the battle over what it means for a false claim to “result from” a kickback, as discussed in our False Claims Act: 2024 Year in Review.
With the fight becoming increasingly one-sided — the Third Circuit remains the only circuit that has adopted a less stringent causation standard — the government may look at alternative theories to link the AKS and FCA.
Key Issues and the Parties’ Positions
As outlined in our previous posts on the issue, the legal dispute revolves around the interpretation of the 2010 amendment to the AKS, which states that claims “resulting from” a kickback constitute false or fraudulent claims under the FCA.
In this case, the government accused Regeneron of violating the AKS by indirectly covering Medicare copayments for its drug, Eylea, through donations to a third-party foundation. The government’s key argument relied on the Third Circuit’s Greenfield decision, the AKS’s statutory structure, and the 2010 amendment’s legislative history to argue that a stringent causation standard would defeat the amendment’s purpose. It urged the court to find that once a claim is tied to an AKS violation, it should automatically be considered false under the FCA — without the need to prove that the violation directly influenced the claim.
Regeneron, on the other hand, argued that an FCA violation only occurs if the kickback was the determining factor in the submission of the claim. Relying on the Eighth and Sixth Circuits’ decisions, prior Supreme Court precedent, and a textual reading of the amendment, Regeneron contended that the phrase “resulting from” could only mean actual causation and nothing less.
The Court’s Decision
The First Circuit sided with Regeneron. It found that, given the Supreme Court’s prior interpretation of “resulting from” phrase as requiring but-for causation, this should be the default assumption when a statute uses that language. While acknowledging that statutory context could, in some cases, suggest a different standard, the court concluded that the government failed to provide sufficient contextual justification for a departure from but-for causation.
The court rejected the government’s argument that, in the broader context of the AKS statutory scheme, it would be counterintuitive for Congress to impose a more stringent causation standard for civil AKS violations than for criminal AKS violations, which require no proof of causation. The court also dismissed the government’s legislative history argument — specifically, the claim that a but-for causation standard would undermine the impetus for the amendment.
Implication: False Certification Theories May Become More Prominent
The First Circuit was careful to distinguish between the per se liability at issue in this case and liability under a false certification theory. While the government must show but-for causation for an AKS violation to automatically give rise to FCA liability, the court said that the same is not true for false certification claims.
Any entity that submits claims for payment under federal healthcare programs certifies — either explicitly or implicitly — that it has complied with the AKS. The court noted that nothing in the 2010 amendment requires proof of but-for causation in a false certification case. The government may take this as a cue to pivot toward false certification claims as a means of linking the AKS and FCA, potentially leaving the 2010 amendment argument behind.
Final Thoughts
The First Circuit’s decision in U.S. v. Regeneron Pharmaceuticals further cements the dominance of the “but for” causation standard in linking AKS violations to FCA liability, making it increasingly difficult for the government to pursue claims under a per se liability theory. With three circuits now aligned on this interpretation and only the Third Circuit standing apart, the tide appears to be turning in favor of a stricter causation requirement.
However, as the court acknowledged, this ruling may not foreclose other avenues for FCA liability — particularly false certification claims, which at least this court has found do not require the same level of causal proof. Given this, the government may shift its focus toward alternative enforcement strategies to maintain the strength of its anti-kickback enforcement efforts. As the legal landscape continues to evolve, healthcare entities and compliance professionals should remain vigilant, as new litigation trends and regulatory responses may reshape the interplay between the AKS and FCA in the years to come.