In an important development in the emerging body of caselaw on the application of the “but-for” causation standard to False Claims Act cases predicated on alleged violations of the anti-kickback statute, the court in United States ex rel. Witkin v. Medtronic, Inc., No. 1:11-cv-10790-IT (Nov. 14, 2025, D. Mass.), has once again denied Medtronic’s motion for summary judgment on relator’s claims that Medtronic’s alleged kickbacks to medical providers caused the submission of false claims to Federal health care programs.
In March 2024, the court denied Medtronic’s initial motion for summary judgment (which had been pending for years before another judge). United States ex rel. Witkin v. Medtronic, Inc., 2024 WL 1892405, at *18 (D. Mass. Mar. 31, 2024). In its 2024 decision, the court found that, in order to establish liability under the 2010 amendment to the anti-kickback statute, 42 U.S.C. § 1320a-7b(g), the relator need not put forth evidence to show that Medtronic’s alleged kickbacks were the but-for cause of false claims.
In a different case, the First Circuit subsequently rejected the Medtronic court’s view, finding that the “resulting from” language in the 2010 amendment implied a but-for causation standard. United States v. Regeneron Pharmaceuticals, Inc., 128 F.4th 324 (1st Cir. 2025).
In light of the Regeneron decision, Medtronic moved for reconsideration, and the court granted that motion as to application of the but-for causation standard. But the court still denied Medtronic’s renewed motion for summary judgment, finding that relator’s evidence created a genuine dispute of material fact on the question of but-for causation. In the course of reaching this conclusion, the court cited the district court decision in Regeneron, where the “court noted that the [but-for] standard does not require ‘prov[ing] that the AKS violation was the only cause of the resulting false claim[,]’ but rather that ‘it was more likely than not that the AKS violation was the cause of the false claim[,]’ which may be proven ‘through circumstantial evidence and reasonable inferences.’” Medtronic, slip op. at 6 (quoting United States v. Regeneron Pharms., Inc., 2023 WL 6296393, at *12 (D. Mass. Sept. 27, 2023)).
In finding support for a showing of but-for causation, the Medtronic court “considered evidence matching the presence of Medtronic personnel with an uptick in specific claims submitted by healthcare providers.” Id. at 7. In particular, the court noted that the relator “submitted evidence of CMS claims data from physicians who had Medtronic sales representatives and Managers extensively and repeatedly participate in . . . clinics [that the Medtronic personnel allegedly ran on behalf of the physicians], and has provided temporal links between certain physicians’ claims data to certain patients known to have attended [the] clinics.” Id.
The Medtronic decision is important because it is, so far as I am aware, the first to apply the First Circuit’s Regeneron but-for causation standard and find that a relator’s evidence was sufficient to deny summary judgment to the defendant. In other words, the decision shows that the but-for causation standard is hardly the insurmountable hurdle that some defense counsel make it out to be.
Notably, the Medtronic court also denied Medtronic’s motion for summary judgment based on the false certification theory that the First Circuit in Regeneron had identified as a separate “pathway” for proving False Claims Act liability premised on violations of the anti-kickback standard. The court noted that the First Circuit’s decision did not change pre-existing law on false certification, and that, in any event, Medtronic previously had “failed to argue for summary judgment on the false certification theory.” Id. at 11.