
On Feb. 18, 2025, the U.S. Court of Appeals for the First Circuit adopted the “but for” causality standard for violations of the federal Anti-Kickback Statute (AKS) that give rise to violations of the federal False Claims Act (FCA). In United States v. Regeneron, the First Circuit held that for a violation of the AKS to constitute a false claim subject to the FCA, the government must demonstrate that the illicit kickback was the “but for” cause of a submitted claim.
This holding ended an intra-circuit split between two district court opinions including the lower court’s ruling in this case and aligns the First Circuit with the Sixth and Eighth circuits’ interpretations. The holding leaves the Third Circuit as the only circuit allowing the government to rely on a “causal link” standard between an AKS violation and the submission of a false claim subject to the FCA.