Federal enforcement of the False Claims Act (FCA) against healthcare and pharmaceutical companies—especially based on alleged Anti-Kickback Statute (AKS) violations—continues to change, with the Regeneron Pharmaceuticals case at the forefront of recent developments. Recall that in Regeneron, the government alleges that the pharmaceutical company is illegally subsidizing copayments for Medicare beneficiaries by making large donations to third party foundations offering copay assistance to strategically steer patients to its high-cost specialty drug, Eylea, instead of lower-cost alternatives, resulting in alleged FCA liability based on an AKS violation. After the First Circuit held that a FCA plaintiff in an AKS-based FCA case must prove “actual causality, which in ordinary course takes the form of but-for causation,” United States v. Regeneron Pharms., Inc., 128 F.4th 324, 330 (1st Cir. 2025), the government is trying—again—to avoid having to prove a causal link between the alleged AKS violation and damages (i.e., financial harm to a government program). The government’s recent summary judgment brief in the United States District Court for the District of Massachusetts provides a detailed look at both its evolving legal theory and the practical compliance lessons for pharmaceutical manufacturers, providers, and health systems.
The Government’s Summary Judgment Motion: Key Arguments
In its October 2025 summary judgment brief, the DOJ seeks to resolve several legal issues before trial. First, the government asks the court to rule that every Medicare Part B claim for Eylea submitted between 2013 and 2014 included a representation—either express or implied—of compliance with the AKS. These certifications appear in the CMS-1500 paper claims, the electronic EDI Enrollment Forms, and the Medicare provider enrollment agreements, each of which obligates providers to comply with federal law, including the AKS.
The government’s brief emphasizes that providers must make these representations at the time of program enrollment and with every claim submitted. Citing First Circuit precedent, DOJ argues that these compliance certifications are material and central to the government’s decision to pay claims. The government is not asking the court to decide whether Regeneron actually violated the AKS—that issue is reserved for the jury—but instead seeks a determination that each claim at issue “represented” compliance, satisfying the first and fundamental element of FCA falsity under both express and implied certification theories.
A Shift in FCA Causation: Moving Beyond “But-For”?
The summary judgment motion is notable for its treatment of the causation standard in FCA cases based on false certification. Traditionally, the government must meet a “but-for” causation threshold, proving a false claim would not have been submitted without the alleged kickback. The First Circuit analyzed this issue in the case earlier this year, where the government argued that the alleged conduct resulted in a false claim. This theory is based on a 2010 amendment to the AKS which added language stating a “claim that includes items or services resulting from a violation of [the AKS] constitutes a false or fraudulent claim for purposes of [the FCA].” 42 U.S.C.§1320a-7b(g) (emphasis added). In other words, an “AKS violation that results in a federal [healthcare] payment is a per se false claim under the FCA.” Guilfoilev. Shields, 913 F.3d 178, 190 (1st Cir. 2019) (quoting United States ex rel. Lutz v. United States, 853 F.3d 131, 135 (4th Cir. 2017)). The First Circuit, like others, held that this requires the FCA plaintiff in such cases to prove actual causation. It noted, however, that the 2010 amendment only affected FCA cases in which the AKS violation results in a false claim – it would not impact the false certification FCA cases. As the Regeneron court stated, “[p]ut simply, claims under the 2010 amendment run on a separate track than do claims under a false-certification theory . . . In sum, there is certainly a pathway to FCA liability for an AKS violation when someone falsely represents compliance with a material requirement that there be no AKS violation in connection with the claim. Under that pathway, it is not the AKS violation itself that renders the claim false. Rather, it is the false representation that there is no AKS violation.” 128 F.4th at 333-34. As such, “false-certification claims require no proof of causation.” Id. at 334. Therefore, the government argues that it need only show that Regeneron’s conduct “naturally and foreseeably” led to the submission of claims with false compliance certifications.
This is a significant development. Now, DOJ must demonstrate only that Regeneron’s contributions to the Chronic Disease Fund (CDF)—a foundation that provides copay assistance— were a substantial factor in causing the claims at issue to be submitted—rather than the sole reason claims were made. This broader proximate cause approach is supported by First Circuit authority and helps the government address the challenges of proving direct causation in complex healthcare arrangements.
However, while this may be sufficient for proving liability, in order to recover any damages, a FCA plaintiff must prove “that the specific misrepresentations made to” the agency “in this case were the direct and proximate cause of” the Government agencies’ “losses and not merely the ‘but for’ cause of those losses.” United States ex rel. Fago v. M&T Mortg. Corp., 518 F. Supp. 2d 108, 122 (D.D.C. 2007) (citing United States ex rel. Schwedt, 59 F.3d at 200); United States v. Hibbs, 568 F.2d 347, 351 (3d Cir. 1977)). In joining the D.C. Circuit and all other circuits in adopting the proximate causation standard for FCA cases, the Seventh Circuit explained that proximate cause requires a showing of both cause in fact and legal cause:
Proximate cause encompasses both cause in fact and legal cause. To establish cause in fact, the plaintiff must show the defendant’s “conduct was a material element and a substantial factor in bringing about the injury.” Legal cause on the other hand, “is essentially a question of foreseeability,” and we must determine “whether the injury is of a type that a reasonable person would see as a likely result of his or her conduct.”
United States v. Luce, 873 F.3d 999, 1012 (7th Cir. 2017) (citation omitted). Accordingly, despite its pleas to the contrary, the government will still need to prove a causal nexus, at least if it wants damages.
Why Materiality Matters
The brief also addresses materiality—the legal requirement that a misrepresentation “tends to influence” government payment. There is a trade-off between a false claim and a false certification case. In a false claim case (i.e., proceeding under the 2010 amendment), the plaintiff must plead and establish but-for causation. The trade-off is that “[t]here is no [] materiality requirement for claims brought under the 2010 amendment.” Regeneron, 128 F.4th at 334(citing Guilfoile v. Shields, 913 F.3d 178, 190 (1st Cir. 2019)). But in a false certification case, the FCA plaintiff must plead and prove that the defendant’s certification of AKS compliance “was material to the Government’s payment decision.” Id.
The government in its summary judgment argument emphasizes that AKS compliance is routinely enforced and viewed as a condition of Medicare payment. Drawing on Supreme Court and First Circuit precedent, as well as evidence of extensive FCA enforcement for AKS-related violations, DOJ contends that noncompliance with AKS is material as a matter of law. Therefore, any claim tainted by a kickback—not just those where but-for causality is proven—is sufficient to trigger FCA liability.
Regeneron’s Conduct and Defense
The government’s factual presentation includes allegations that Regeneron funneled tens of millions of dollars through the CDF with the goal of increasing Eylea claims. The brief claims Regeneron employees solicited Eylea-specific data, used ROI analysis to size contributions, and even concealed relevant facts during internal audits—a narrative designed to support findings of willfulness and intent. Regeneron’s defense is that its donations to CDF were lawful, did not affect prescribing, and that its drug pricing followed industry guidance.
Broader Implications for Industry
If the court adopts the government’s position, the summary judgment ruling will clarify and lower the bar for FCA liability in AKS cases. Companies may be liable if their conduct leads to false claims, even without proof of direct causation. Courts would focus more on the content and materiality of certifications made in claims than on untangling the precise effect of each alleged kickback or pricing practice.
This means that health care companies, pharmaceutical manufacturers, providers, and other entities involved with federal health programs must ensure that all business practices, certifications, supporting documentation, and compliance measures are not only accurate but withstand a “foreseeability” review. The government’s brief is clear: compliance with the AKS and federal requirements is not “fine print”—it is fundamental to every claim submitted.
Key Takeaways
- Be vigilant with certifications: Every Medicare claim and provider agreement is a representation of compliance. Check that your day-to-day practices align with what is being promised.
- Understand the potential implications of a lower causation bar: You could face FCA liability risk if your actions foreseeably lead to tainted claims, even if you do not directly submit the claim.
- Materiality is key: Government payment depends on truthful compliance statements. AKS compliance is never “minor or insubstantial.”
- Documentation and training are critical: Create and maintain robust, clear documentation around patient assistance programs, pricing decisions, and compliance representations.