From Kickbacks to False Claims: The Causation Consequences of the 2010 Anti-Kickback Statute Amendment

I.  Introduction

In 2018, five doctors were indicted for participating in a bribery and kickback scheme that sought to increase the sales of a drug company, Insys Therapeutics (Insys).1 Insys manufactured Subsys, a spray form of fentanyl, which was approved by the FDA to treat cancer patients who were undergoing opioid therapy.2 In 2013, with the nationwide opioid crisis in full swing, Dr. Gordon Freedman, a prominent physician in Manhattan, agreed to increase the number of new patients to whom he was prescribing Subsys in exchange for a kickback—an illegal payment or transfer of something of value in exchange for receiving preferential treatment—from Insys.3 By 2014, Dr. Freedman was one of the country’s top prescribers of this highly addictive synthetic opioid and also Insys’s highest-paid educational speaker.4 One of Dr. Freedman’s patients, who was illegally prescribed Subsys, ultimately passed away of a fentanyl overdose.5

Dr. Freedman was far from the only one engaged in this pernicious scheme. Insys admitted to paying doctors upwards of $100,000 annually to prescribe Subsys, funneling payments through a “speakers bureau” that purported to compensate doctors for delivering educational presentations on the drug—presentations that rarely took place.6 This sham speaker program and use of kickbacks increased brand awareness, the number of Subsys prescriptions, and dosages of the drug.7 A physician assistant, after never having prescribed Subsys for his patients, wrote 672 Subsys scripts within just a few years—many of which were medically unnecessary.8 He ultimately received $44,000 in kickbacks for his role in Insys’s scheme.9 In other cases, Insys provided kickbacks in the “form of jobs for prescribers’ relatives [ ] and lavish meals and entertainment.”10

Thousands of innocent patients, many of whom did not need access to opioid treatment, fell victim to this kickback scheme.11 As charged in the indictment, Insys encouraged physicians to prescribe Subsys for non-cancer patients and “lied to insurers about . . . diagnoses in order to obtain reimbursement for Subsys prescriptions that had been written for Medicare and TRICARE beneficiaries.”12 Once this sophisticated pattern of fraud came to light, it prompted a series of civil and criminal investigations. Insys ultimately entered into a $225 million resolution—including $195 million to settle allegations that it violated the False Claims Act (FCA).13 Ultimately, under the weight of this resolution, Insys filed for bankruptcy in 2019.14 This case is just one of many      demonstrating how common medical kickback schemes are and the negative impact on the livelihood and well-being of thousands of innocent patients who trust their doctors to afford them with high-quality medical care.15

Given the extreme human cost of healthcare fraud, the government has robust measures to address it. Along with the FCA, the Anti-Kickback Statute (AKS) forms the basis of the federal government’s statutory enforcement arsenal. The FCA provides that any person who “knowingly presents . . . a false or fraudulent claim for payment or approval” is liable for “[three] times the amount of damages which the Government sustains” in addition to a civil penalty.16 As one of the most successful anti-fraud acts in the United States, the FCA serves as a way for both the federal government and whistleblowers (whom the FCA’s qui tam provision make eligible to receive a portion of any penalties imposed as a result of their disclosures) to disclose fraud resulting in financial loss to the government.17 The AKS makes it illegal for anyone to knowingly and willfully ask for or receive any kind of payment in exchange for referring someone to a provider of services or items that are paid for, at least in part, by a federal healthcare program.18 Prohibited exchanges can take a variety of forms including any “kickback, bribe, or rebate” either “directly or indirectly, overtly or covertly, in cash or in kind.”19 The FCA and AKS reinforce one another. When a medical professional submits a claim to Medicare or Medicaid that includes items or services resulting from a violation of the AKS, the claims are deemed to be false even if the defendant did not have the specific intent to violate the AKS.20 Violating the AKS and eventually submitting claims to Medicare is thus both a felony and imposes civil liability under the FCA.21

But the effectiveness of this interwoven statutory regime depends upon a thorny question of statutory interpretation. In 2010, Congress passed the AKS Amendment to try to more clearly tie these statutes together. To meet the falsity requirement under the FCA, meaning the claim for reimbursement is false in order to impose FCA liability, the AKS Amendment required that the submitted false claim “include items or services ‘resulting from’ a violation of the AKS.”22  The “resulting from” language that links these two statutes together has created a deep circuit split as courts grapple with the causation standard that should apply when evaluating claims under the FCA predicated on AKS violations. The main question courts seek to resolve is how strong the link must be between an AKS violation and the eventual submission of a claim under a federal healthcare program, like Medicare or Medicaid.23 This causation question inherently decides the distributive consequences the AKS and FCA could have on pharmaceutical companies and other medical professionals engaging in deceptive bribery engagements.24 Courts have applied traditional tools of statutory interpretation in an attempt to answer this question. The legal outcome can mean the difference between more leniently permitting customer-facing activities and necessitating a strict oversight program as to the activities companies can endorse to prevent influencing a provider’s medical judgment.25

Currently, four circuits have ruled likely making this complex causation issue ripe for Supreme Court review. The Sixth, Eighth, and most recently, First Circuit, demand but-for causation.26 A but-for causation standard means that “the plaintiff . . . must prove that the ultimate submission of a false claim would not have occurred ‘but-for’ the AKS violation.”27 The Third Circuit has landed on the opposite side of the debate, proposing a looser causation standard, requiring “some connection”28 between the illegal kickback and ultimate referral to find liability. In other words, the First, Sixth, and Eighth Circuits require proof that a doctor only submitted a fraudulent payment due to the illegal kickback, while evidence that shows a link between the kickback payment and subsequent claim to a federal program suffices for the Third Circuit.29

This Comment aims to resolve the circuit split differently from other scholarly analysis, which has mostly focused on the statutory interpretation tools used by the courts.30  Instead, this Comment argues that the evidentiary burdens placed on both plaintiffs and defendants in these causation regimes are a better metric for understanding the practical effects each causation standard would have on future litigation. This Comment argues that for the government to successfully use the AKS to combat healthcare fraud under the FCA, courts should introduce a burden-shifting framework. While a plaintiff bears the burden of persuasion when bringing a suit, given the evidentiary complexities in AKS claims that will be discussed below, this framework would permit the burden of persuasion to shift to the defendant to combat the prima facie case made by the plaintiff. This approach would both lessen the evidentiary burdens placed on the government while ensuring it demonstrates more than just a tenuous link between the claim submitted and the alleged kickback.

This Comment will proceed in four parts. First, Part II begins by providing a historical background of the AKS and the FCA, while further explaining how these two federal statutes interact with each other. Second, Part III explains the current circuit split while delineating the likely costs and benefits of using the different causation standards. Part III also attempts to ground the various options in their human consequences, attending to the profound impacts either causation standard could have on future litigation and business practices by pharmaceutical companies and medical professionals alike. Finally, Part IV concludes by proposing that a burden-shifting framework be applied to help resolve the question as to which causation standard should be used when determining whether false claims filed under a federal health care program resulted from a kickback. This proposal would force both plaintiffs and defendants to bear some of the evidentiary burden, helping the courts to provide a better resolve to the issues that each causation standard presents.

II.  Historical Background of the Anti-Kickback Statute and the False Claims Act

A.  Expanding the AKS’s Prosecutorial Reach

The AKS underwent a series of varying iterations before transforming into one of the most powerful statutes to combat healthcare fraud by imposing criminal penalties. The AKS was enacted in 1972 through the Social Security Amendments during the Nixon administration to combat fraud and abuse in the Medicare and Medicaid Programs.31 Since 1965, these government-sponsored health programs have provided health insurance coverage to millions of Americans.32 While the AKS is now a stand-alone statute targeting complex fraudulent schemes, it began as a statute that merely made it a misdemeanor to “solicit[ ], offer[ ], or receive[ ] any . . . kickback or bribe in connection with furnishing of such items or services.”33 In 1977, Congress amended the statute to make AKS violations felonies and to “broaden[ ] the statutory language to prohibit ‘any remuneration’ provided to induce referrals.”34 Within the regulatory framework governing AKS violations, a remuneration includes anything of value used to induce or reward patient referrals or the generation of business.35 The statute explicitly states that these remunerations can be a “kickback, bribe, or rebate” and can be prescribed “directly or indirectly, overtly or covertly, in cash or in kind.”36 Insys Therapeutics used both evident remunerations like cash and bonuses, but also in kind remunerations incentivizing medical professionals to prescribe higher numbers of Subsys by offering jobs to family members.37

If the federal government didn’t prosecute kickbacks, “patients [could] receive goods and services that are medically inappropriate, unduly costly, medically unnecessary, and of poor quality.”38 As per data from 2023, 18.9% of the population of the United States was covered by Medicaid and another 18.9% was covered by Medicare.39 Any patient whose insurance is covered by one of these federally funded programs is subject to heightened influence by medical providers who could refer them to a particular person or encourage them to use a particular medication and ultimately submit a fraudulent claim as the result of kickbacks.40 Later, in 1980, Congress amended the AKS to require that one “knowingly and willfully” solicited, received, or offered a remuneration.41 Congress’s decision to amend and further expand the prosecutorial reach of the AKS between 1972 and 2010 demonstrates its concern that kickbacks would severely corrupt professional decision-making and endanger vulnerable populations.42 The current articulation of the AKS statute prohibits any person or entity from “knowingly and willfully solicit[ing] or receiv[ing] any remuneration . . . in return for referring an individual to a person for the furnishing or arranging for the furnishing of any item or service for which payment may be made in whole or in part under a Federal health care program.”43

As Congress continued to develop the AKS into the statutory powerhouse that it is today, courts added to its prosecutorial strength. The Third Circuit, in United States v. Greber,44 established what is known as the “one purpose” test that is now widely used by federal courts. The defendant in this case was a physician and president of Cardio-Med, Inc., a company that provided various cardiac diagnoses, including a Holter-monitor testing.45 Once Cardio-Med received payment after billing Medicare, a portion was forwarded to the referring physician.46 While the physician would spend some time interpreting the monitor, they were actually paid much higher fees to induce future referrals.47 Dr. Greber argued that compensating a physician for services actually rendered could not violate the AKS unless the government proved that the only purpose of the fee was to improperly induce future services.48 The Third Circuit held, however, that if “one purpose of the payment was to induce future referrals, the . . . statute has been violated.”49  The Third Circuit heavily relied on precedent from United States v. Hancock50 and Congressional intent that sought to prevent an unnecessary strain on the Medicare system.51 The court found both the language and purpose of the statute sufficiently convincing because even though Dr. Greber performed some service for the money received, “Congress intended to combat financial incentives to physicians for ordering particular services patients did not require.”52 In Hancock, the Seventh Circuit found that chiropractors handling fees and performing legitimate services, was still enough to constitute a kickback, and thus, criminal activity.53 When Congress decided to add “remuneration” to the statute, the Third Circuit found that “Congress [essentially] sought to make it clear that even if the transaction was not considered to be a ‘kickback’ for which no service had been rendered, payment nevertheless violated the Act.”54 Reliance on the Seventh Circuit’s decision in Hancock essentially enabled the Third Circuit to set the stage for prosecutions under the AKS, clearly establishing that one of the key elements for intent in targeting kickbacks requires only “one purpose” to influence, further demonstrating the long statutory arm of the AKS.

B.  A Brief Overview of the FCA

Having set the stage for prosecutions under the AKS, it is then necessary to pivot to the False Claims Act (FCA) and understand how the statutes interact with one another. The FCA states that any person is liable for knowingly submitting a false claim to the government.55 Examples of false claims include billing for goods or services that were never delivered, double billing for the same good or service, or misrepresenting costs related to performance or quality of the good.56 The original FCA was enacted in 1863 when President Abraham Lincoln sought to punish war profiteers who were defrauding Union troops by overcharging for standard or non-existent products.57 Central to the original FCA were its qui tam provisions, which allowed private citizens to file suits on behalf of the government.58 The FCA’s 1943 Amendments diminished the shares private citizens could reap and didn’t permit a qui tam case from moving forward if the suit was based on evidence or information already in possession of the federal government—but, the restriction on qui tam lawsuits ultimately proved to be a mistake.59  After a steep rise in defense contractor fraud during the 1970s and 1980s, Congress realized that it would be difficult to uncover such technical and complex fraud without an insider’s knowledge.60 Thus, the 1986 Amendment reinvigorated qui tam lawsuits and remains a quintessential provision of FCA litigation.

C.  How the AKS and FCA Work Together in Healthcare Fraud Enforcement

Congress used the 2010 amendment to tie an AKS violation as the basis of a fraudulent claim submitted for reimbursement to a federal health care program, like Medicare, to the FCA.61 Congress had grown concerned that even claims that resulted from a kickback were not being prosecuted under the FCA if submitted by a third party.62 Prior to the 2010 amendment, it was possible for a medical device company to pay a kickback to a doctor and not be held liable under the FCA since the final claim was submitted by the hospital, and not the guilty doctor himself.63 Thus, the 2010 amendment to the AKS sought to target all false or fraudulent claims resulting from illegal kickbacks, even when the claims were not submitted directly by the wrongdoers themselves.64

Although the purpose of the FCA is to target false claims submitted to the government, it was clear to Congress that activities rising to the level of kickback schemes were falling outside the purview of the FCA due to a simple technicality. The 2010 amendment was used in order to close this loophole and clarify the falsity prong of the FCA, stating that “a claim [for payment by a federal healthcare program] that includes items or services resulting from a violation of [the AKS] constitutes a false or fraudulent claim.”65 Furthermore, Congress removed the requirement of actual knowledge, meaning the individual no longer had to have specific intent to violate the AKS in order to constitute willful conduct.66 Put plainly, the AKS is a way to prove that a claim is false or fraudulent. Whether a violation of the AKS is also a false claim under the FCA makes a difference because the FCA allows both the government and whistleblowers to bring civil actions for damages.

The AKS has proven crucial to successful fraud enforcement under the FCA and is often the statute generating the most FCA dollars.67 While the FCA covers all fraudulent claims submitted to the government, a majority of FCA recovery over the last decade falls under the umbrella of healthcare fraud.68 In 2023, 66% of total FCA violation recoveries were from healthcare fraud matters.69 In 2022, a $900 million dollar Biogen settlement pertaining solely to kickbacks represented almost half of the FCA’s “$2.2 billion haul for all of 2022.”70 Not only was there a clear social reason to target healthcare fraud, but there was a clear financial incentive to ensure that these kickback schemes were prosecuted.71 In 2008, the Medicare program lost more than $10 billion to fraud.72 The 2010 amendment intended to clarify that claims tainted by kickbacks are necessarily false, and thus prosecutable under the FCA.73 In the process of expounding the falsity element, however, Congress did not anticipate a flurry of litigation around two simple words: “resulting from.” Again, § 1320a-7b(g) states that a claim including “items or services resulting from a violation of [the AKS] constitutes a false or fraudulent claim for purposes of [the FCA].”74  Ultimately, courts have been left to determine how tenuous causation must be to link claims for reimbursements under the FCA to alleged kickback schemes by individual medical professionals and larger healthcare industries.

III.  Current Circuit Split

Courts have had to clarify the causal connection between an AKS violation and a later reimbursement claim under the FCA.75  Four circuits have ruled on the appropriate standard of causation for AKS-based FCA claims. The First, Sixth, and Eighth Circuits have each held that a plaintiff must prove that the submission of a false claim would not have occurred but-for the AKS violation.76 The Third Circuit is the only court to hold that no such proof is required.77 The First Circuit recently issued a ruling in United States v. Regeneron Pharmaceuticals, Inc.,78 on February 18, 2025, deepening the issue to a resulting 3-1 split. The recency of the First Circuit’s decision and the deepening circuit split makes Supreme Court review feel inevitable.79

A.  The Eighth Circuit’s But-For Causation Requirement

The Eighth Circuit decided this issue in the case of United States ex rel. Cairns v. D.S. Medical LLC.80 The defendant in that case was a neurosurgeon, Dr. Fonn, who treated degenerative-disc disease by using spine implants.81 He decided “to use implants distributed by DS Medical, a company wholly owned by his fiancée.”82 The government filed a complaint which “alleged that the couple and their businesses submitted false or fraudulent Medicare and Medicaid claims after violating the anti-kickback statute.”83  DS Medical allegedly earned a sizable commission from manufacturers for every implant sold.84 Dr. Fonn purchased stock in one manufacturer’s company that paid DS Medical a commission of $1.3 million.85 After the stock purchase was complete, Dr. Fonn continued to order more implants from DS Medical.86

The court primarily looked to the District Court’s misinterpretation of the 2010 amendment to the AKS. At trial, the district court instructed the jury that “‘it is enough for the United States to show that the claim failed to disclose the [a]nti-[k]ickback [s]tatute violation.’”87 On appeal, the Eighth Circuit considered whether the instruction misinterpreted the 2010 amendment by ignoring any issue with the causation standard.88 Much of the statutory interpretation employed by the Eight Circuit relied on precedent from the Supreme Court’s interpretation of “results from” language in Burrage v. United States.89 There, the Court was tasked with interpreting the Controlled Substances Act, which imposes a sentence “on a defendant who unlawfully distributes a Schedule I or II drug, when ‘death or serious bodily injury results from the use of such substance.’”90 The Court ultimately held that “the use of drugs had to be a ‘but-for cause of the death’” to impose a penalty enhancement provision on the defendant.91 The government, in Cairns, advanced an alternative causal standard, arguing that all that should be required is evidence that the anti-kickback violation may have been a contributing factor.92 The court was not persuaded, asserting that “asking the jury if a violation ‘may have been a contributing factor’ does not establish anything more than a mere possibility.”93 The Eighth Circuit made it clear that causation must be proven, not presumed.

Furthermore, the government aimed to convince the court of the significance of legislative history and intent, but the Eighth Circuit emphasized that “our duty is to ‘interpret laws,’ not ‘reconstruct legislators’ intentions.’”94 Relying heavily on Supreme Court precedent, the language of the statute itself, and dictionaries, the Eighth Circuit held that a stricter standard applied: one that required the government prove “that a defendant would have not included particular ‘items or services’ but-for the illegal kickbacks” when establishing fraud through the 2010 amendment.95 Put simply, in order to prove that a claim is false under the FCA due to an AKS violation, a plaintiff in the Eighth Circuit must demonstrate that the kickback itself was the actual cause of the submitted claim. It is not enough for a kickback to have merely tainted a false claim.

B.  The Sixth Circuit Follows Suit

Shortly after the Eighth Circuit decided on a but-for causation standard, the Sixth Circuit followed closely in its footsteps. The Sixth Circuit found itself interpreting the same “resulting from” language from § 1320a-7b(g), which states that a claim including “items or services resulting from a violation of [the AKS] constitutes a false or fraudulent claim for purposes of [the FCA].”96 United States ex rel. Martin v. Hathaway97 concerned an ophthalmologist’s allegations that a local hospital violated the AKS by “rejecting [his] employment in return for [another ophthalmologist’s] commitment to continue sending local surgery referrals to the hospital.”98 Under allegations of fraud, plaintiffs must “‘adequately allege the entire chain—from start to finish—to fairly show defendants caused false claims to be filed.’”99 After reviewing the filed complaint, the court identified two legal flaws under the AKS and FCA—the first being a mischaracterization of the theory of remuneration and the second focusing on the appropriate causation standard.100

The court held that this scheme did not constitute a remuneration, as that typically “requires a payment or transfer of value to another.”101  The decision to not hire someone did not entail any payment or transfer of value.102 More importantly for the purposes of this Comment, however, was the court’s analysis in determining the adequate causation standard. Similar to the reasoning used in the Eighth Circuit, the court in Hathaway found that the ordinary meaning of “resulting from” is but-for causation, “unless strong ‘textual or contextual indication[s]’ indicate a ‘contrary’ meaning.”103 The Sixth Circuit explained that in establishing a but-for causation standard, its goal was to “target” only “genuine corruption,” without permitting a broad and loose reading of the AKS.104 Hathaway thus held that “[s]o long as proof exists that the referrals would not have been made without the remuneration, and that claims would not have been submitted to the government without those referrals, causation for False Claims lawsuits would be satisfied too.”105 Again, the court chose to ignore legislative history and stick to the “common” understanding that “resulting from” implies but-for causation.

C.  The First Circuit Reinforces the Need for But-For Causation

In the court’s opinion issued at the beginning of the year in United States v. Regeneron Pharmaceuticals. Inc.,106 the First Circuit aligned itself with the Sixth and Eighth Circuits, reinforcing an interpretation of the 2010 amendment that requires a but-for causation standard. The causation issue made its way to the First Circuit when two cases in Massachusetts federal district court—United States v. Teva Pharmaceuticals USA, Inc.107 and United States v. Regeneron Pharmaceuticals, Inc.108 —were simultaneously decided and perfectly mirrored the current circuit split. In Teva, the judge concluded that the Third Circuit’s standard from Greenfield should apply,109 while the judge in Regeneron decided to apply the causation standard used in the Sixth and Eighth Circuits.110 Given the conflicting standards within the same district and the direct impact on future litigation, “[t]win interlocutory appeals were brought before the court.”111 The Teva litigation ultimately reached a settlement agreement of $450 million.112 The recent decision from the Regeneron appeal, however, has garnered ample attention as the court’s ruling has given much more legitimacy to the but-for causation standard.

In Regeneron, the government alleged that the pharmaceutical company improperly paid millions of dollars to the Chronic Disease Fund (CDF) to subsidize patient copays for Eylea—a drug that treats “neovascular [wet] age-related macular degeneration.”113 A “buy and bill” drug, “doctors buy [Eylea], prescribe it, administer it in their officers, and then submit a reimbursement claim to Medicare.”114 Manufacturers may sometimes rebate co-pays such that patients don’t have a co-pay, making patients much more willing and able to use a particular prescription. However, a direct rebate by the manufacturer would be a kickback—a doctor would essentially be accepting a payment that results in a lower co-pay, inducing them to prescribe that particular drug to more patients. To avoid punishment for this clear violation of the AKS, manufacturers will often donate to foundations that help with co-pays so that the payment isn’t being made to the doctor directly.115 Thus, the complaint in this case alleges that Regeneron’s effort to pay more than $60 million116 to CDF specifically to reimburse the copayments of Eylea, violated the AKS.

In Regeneron, the district court found the Greenfield court’s reasoning “fraught with problems,”117 and chose to adopt the precedent set forth in both the Eighth and Sixth Circuits. While the court in Cairns and Hathaway largely sidestepped the evidentiary burden plaintiffs face in needing to prove but-for causation, the Regeneron court seemed to confront the issue a little more directly, concluding that such evidentiary hurdles would not be an issue.118 The court started by emphasizing a notably low evidentiary threshold, stating that the government “need only prove that it was more likely than not that the AKS violation was the cause of the false claim,”119 implying that “circumstantial evidence and reasonable inferences” should suffice. Simultaneously, however, the court recognized its self-imposed limitations noting that “[evidence] may not be sufficient, and the reasonableness of the inference may be attenuated as the time period grows longer.”120

After certifying the interlocutory appeal, the First Circuit set oral argument for Regeneron to be heard during the summer of 2024, before reaching its final ruling at the beginning of 2025. Through its task of statutory interpretation, the court found that “resulting from” ordinarily necessitates a form of but-for causation, unless textual or contextual indications prove otherwise.121 At the outset, the court found that the government was unable to point to any language “in the 2010 amendment that by itself runs counter to the presumption that ‘resulting from’ calls for proof of but-for causation.”122 Turning to the government’s contextual arguments, the court was yet again, unpersuaded. The court found that the statutory history provides no reason to deviate from the ordinary course in treating “resulting from” as requiring but-for causation. In oral argument, the government emphasized that the “results from” language was meant to serve as the “nexus between an FCA claim premised on an AKS violation, not to require a more stringent, burdensome causation standard.”123 However, the court clarified that Congress has the discretion to require or waive proof of added elements beyond those needed to establish the predicate violation.124 Again, if Congress wanted to make itself more clear, it could have made the violation of one statute a per se violation of another.125

Interestingly, however, is the First Circuit’s mention of the false certification theory linking the FCA and the AKS; a theory not comprehensively discussed by any other circuit. The court states that “[u]nder this theory, a defendant violates the FCA when presenting [ ] a claim that misrepresents compliance with a ‘statutory, regulatory, or contractual requirement.’”126 Simply put, a defendant who falsely represented AKS compliance when seeking reimbursement from Medicare could be liable under the FCA for falsely certifying compliance with the statutory language of the AKS. The court reasoned that under this theory, the government could just find an alternative path for FCA liability under an AKS violation, which does not require proof of but-for causation,127 thus not closing the door on successful FCA liability claims predicated on AKS violations. However, the court heavily weighed the false-certification theory, suggesting that “resulting from” necessitates a but-for causation standard since the false-certification theory, an alternative route to liability, does not require the same stringent causation standard. To the First Circuit, the 2010 amendment merely creates a different pathway to establish falsity in FCA actions without relying on the false-certification theory.128

D.  The Third Circuit’s Looser Causation Requirement

The Third Circuit remains the only circuit which holds that the 2010 amendment of the AKS does not necessitate a but-for causation standard. Instead, all that is required to prove is that a particular patient is exposed to an illegal referral and a provider submits a claim pertaining to that patient,129 a much looser standard than what the three other circuits demand.

The court interpreted this standard when a qui tam action under the FCA was filed against “Accredo Health Group, Inc., a specialty pharmacy that provides home care for patients with hemophilia.”130 The plaintiff, Steve Greenfield, a former area vice president of Accredo, alleged that the specialty pharmacy was linked to a kickback scheme in which Accredo paid kickbacks to Hemophilia Services, Inc. and Hemophilia Association of New Jersey “in the form of charitable contributions to induce recommendations and referrals” to its members.131 At issue in this case was again, what causation standard is needed to connect an alleged kickback scheme to a subsequent claim for reimbursement: “a direct causal link, no link at all, or something in between.”132 The Third Circuit held that a link is required and that the plaintiff must prove that at least one of the defendant’s claims sought for reimbursement violated the AKS.133 In the Third Circuit, a drug manufacturing company will have violated the FCA if a plaintiff can show that she was exposed to an illegal referral and a provider later submitted a claim for reimbursement.

Unlike the other three circuits, the Third Circuit in Greenfield determined that both legislative history and congressional intent were key factors in determining which causation standard to apply.134 Under the theory proposed by Accredo, “a plaintiff would have to prove a kickback actually influenced a patient’s or medical professional’s judgment.”135  This requirement would ultimately negatively affect the success of FCA cases predicated on an AKS violation since healthcare fraud is difficult to prove and “it would dilute the False Claims Act’s requirements vis-à-vis the Anti–Kickback Statute, as direct causation would be a precondition to bringing a False Claims Act case but not an Anti–Kickback Statute case.”136 The AKS is just one of many ways to prove the falsity of a submitted claim to bring liability under the FCA. Separately, however, litigants can bring AKS claims independent of the FCA in situations where no claim was submitted. Thus, this causation distinction elucidates the reality that in order to hold defendants criminally and civilly liable under both the AKS and the FCA, plaintiffs would need to establish a level of causation that isn’t required to prove a claim brought under the AKS independently, albeit being a criminal statute. Thus, unlike the First, Sixth, and Eighth Circuits, the Third Circuit highlighted the difficult evidentiary burden that might be placed on plaintiffs in AKS legislation and the negative impact that could have on successfully prosecuting healthcare fraud—contrary to the intent of Congress in passing the 2010 amendment in the first place. It is incorrect to assume that the Third Circuit merely requires that the claim be tainted; a link still needs to be proven. The mere existence of a kickback scheme would not automatically “taint” every claim submitted to the government during the period that the kickback scheme is alleged to have taken place. The court must have some evidence that shows a link between the alleged kickbacks and the medical care received by at least one of Accredo’s 24 federally insured patients.

E.  The Evidentiary Gap Unresolved by the Current Circuit Split

The different approaches taken by all four circuits has resulted in a deep circuit split, imposing incompatible requirements onto plaintiffs bringing AKS-predicated FCA claims depending on the circuit they are in. There are sufficient fairness concerns that cannot be appropriately compensated through a strict causation standard.137 Where the health of thousands of patients is on the line, at the hands of a medical professional, there is a deep power imbalance that could result in substantial monetary harms as well as long-term health effects. The approach taken by the court in Greenfield means that the government is required “to prove that the defendant submitted at least one claim to a federal health care program that sought reimbursement for services or products provided in violation of the AKS.”138 Even if a doctor would have submitted the same claim absent a payment, if there is evidence of an illegal kickback at any point in the payment chain, that provider will be held liable. Conversely, the causation standard as championed by the court in Cairns means that “[a] plaintiff must prove that false claims would have never been submitted but-for the involvement of an illegal kickback scheme.”139 For example, even if a large pharmaceutical company spent months paying doctors $5,000 bonuses for every additional script referral, a plaintiff could only succeed in its causation claim if it showed that the claim would not have been submitted but-for the $5,000 payments. These conflicting interpretations of “resulting from” can be the determining factor between the government successfully prosecuting a multi-million-dollar fraud scheme and letting pharmaceutical companies continue to bribe doctors into prescribing their products. It is thus imperative that the courts determine what framework will ensure that patients receive the best healthcare services while not over prosecuting healthcare professionals with good intent.

Two common words have resulted in drastically different interpretations by the circuits. As briefly mentioned above, one of the largest factors contributing to the different rulings pertains to the different tools of statutory interpretation used by the circuit courts. The Eighth Circuit was wholly unconvinced by Congressional intent, adamant that it is the job of the courts to interpret Congress’s “actual words” and not the legislative purpose of the statute.140 However, the Third Circuit found that courts’ “effort[s] to discern Congress’s intent may resort to legislative history as an aid or cross-check.”141 Most importantly, however, are the varied approaches taken by the circuits pertaining to evidentiary issues arising from different causation standards.

The Sixth Circuit, for example, failed to address evidentiary concerns when applying a stricter but-for causation standard, raising continued questions as to how a plaintiff must prove that a physician would not have sought reimbursement if not for the related kickback.142  The Eighth Circuit failed to explain the evidentiary burden required to establish but-for causation which would hinder Congress’s objectives, a goal meant to target healthcare fraud and use the strength of the AKS to ensure that claims are prosecuted under the FCA.143 Failing to address this evidentiary burden is a significant issue given the “complexity of the evidence needed to establish a kickback, [since] little evidence may be available for an FCA plaintiff to prove that a patient would not have had the same medical treatment but-for their physician’s illegal kickback.”144 It is additionally important to recognize that “[n]ot only do the violations often include complex transactions, but many times kickbacks are given in-kind, making them even harder to uncover.”145 The Sixth and Eighth Circuits predominantly focused on finding the single best meaning of “resulting from,” but missed the mark on addressing how this could affect the likelihood of plaintiff’s successfully bringing AKS claims.146  The First Circuit addressed the evidentiary burdens that this causation standard may impose on plaintiffs but simply waved away this concern by likening it to the difficulty in proving other elements of a claim.147 The court stated that it did “not doubt that such proof may be more difficult to nail down in some cases,”148 but since the government in this case had enough evidence to get to a jury on the issue of but-for causation, the court’s analysis stopped there.

While the First, Sixth, and Eighth Circuits leave open the question of what evidentiary requirement is expected, the Third Circuit drew out more of a guiding principle, albeit still hazy. Evidence of temporal proximity between the alleged kickback and submission of claims for reimbursement was not sufficient and neither was solely pointing to “any of the 24 [who] received a referral or recommendation to use Accredo’s services.”149 Even while disavowing the mere allegation of a kickback scheme, the Third Circuit still recognized that a stringent but-for causation requirement would counteract the intent of the AKS to strengthen the ability of the Government to detect and prosecute fraudulent activities under federal healthcare programs.150 The Third Circuit is clear that some constraints are necessary to avoid overinclusive results, yet cognizant of the evidentiary burden plaintiffs would have to overcome under a but-for causation standard regime. The best way to resolve this incongruence is to apply a burden-shifting framework, since it analyzes the causation issue through the lens of the evidentiary burdens placed on all parties.

IV.  The Case For A Burden-Shifting Framework

Given the exhaustive analysis on varying canons of statutory interpretation, this Comment’s proposed solution to the existing circuit split first involves articulating the evidentiary burden each causation standard places on parties in AKS litigation. Then, it will argue that for a government to successfully use the AKS to combat healthcare fraud under the FCA, courts should introduce a burden-shifting framework as it would better address existing evidentiary burdens placed on plaintiffs while still forcing the government to demonstrate more than just a tenuous link. The difficulty with the but-for causation standard as it currently stands is that it forces a plaintiff to prove that but-for the illegal kickback, their doctor would not have submitted their claim to Medicaid. Failure to meet this elevated causation requirement results in dismissal of the plaintiffs’ case. A burden-shifting framework would allow a plaintiff to essentially get a presumption of validity from the court, before shifting the burden to the defendant to rebut that favorable presumption.

Thus, irrespective of the causation standard circuits currently employ, this proposed burden-shifting framework would essentially serve as a middle ground—accommodating for the shortcomings of both causation standards currently employed by a few circuits. This Comment focuses on the evidentiary burdens placed on each party in litigation as it addresses fairness concerns, resolves the reality of informational asymmetry in these types of cases, subsides worries of over prosecution, and reaches a middle ground that will level the playing field between both litigants. By analyzing other areas of law in which the burden-shifting framework has proved effective, this Comment argues for its practical use in FCA cases predicated on AKS-violations.

A.  Burden-Shifting Frameworks in Other Areas of Law

1.  McDonnell Douglas test

There are a few examples that demonstrate the burden-shifting doctrine could serve as a viable solution to the seemingly impossible evidentiary burdens in AKS litigation. First, one of the most common justifications for a burden-shifting framework is “where fault or evidence is difficult to pin-down but society has a large interest in protecting plaintiffs.”151 As discussed above, healthcare fraud not only burdens the government, but creates cascading effects that increase insurance premiums and expose patients to harmful, fraudulent medical treatments. Courts that require but-for causation to prove the connection between kickbacks and submitted claims are essentially putting plaintiffs in a difficult position with limited access to that chain of events. Thus, in cases where there is a strong need to protect plaintiffs with a clear obstacle to access sufficiently persuasive evidence, courts have been willing to shift the burden of proof to the defendants to level the playing field.

One of the most widely used burden-shifting tests is known as the McDonnell Douglas152 test, which is used in cases of showing employment discrimination due to the difficulty of “obtain[ing] direct evidence of retaliatory motive.”153 The ultimate “purpose behind the [McDonnell Douglas] framework is to allow plaintiffs to show discrimination in cases where they lack sufficient access to evidence in the defendant’s possession.”154 In using this test, courts have essentially signaled that “the burden of proof should be placed on the defendant because the defendant’s actions have created the problem of proof.”155 The McDonnell Douglas test includes three separate steps. First, the plaintiff must prove by a preponderance of the evidence, a prima facie case of disparate treatment based on his membership in a protected group.156 Second, if the plaintiff succeeds in establishing his prima facie case, the defendant can rebut the presumption of discrimination by providing evidence that the plaintiff was rejected for a “legitimate, nondiscriminatory reason.”157 The defendant just needs to raise a genuine issue of fact to rebut the prima facie case.158 Finally, the burden shifts back to the plaintiff and he must prove, by a preponderance of the evidence, that the provided legitimate reasons were just a pretext for discrimination.159 Courts recognize that in situations like anti-discrimination law, there is an information asymmetry between the employer and employee and thus the onus should not exclusively fall on the plaintiff.160

Similar principles apply in FCA cases predicated on AKS violations. Often plaintiffs may find themselves unable to access evidence in defendant’s possession; especially relevant when kickbacks can come in a variety of different forms—bribes, referrals by word of mouth, and under the table negotiations. As articulated in Part II, the AKS covers a broad range of kickbacks, many of which won’t have sufficient evidence absent an admittance of guilt from the defendants. The “types of evidence needed to file charges against . . . a kickback scheme can become extremely complicated, difficult to uncover, and often require insider information.”161 Additionally, the category of plaintiffs the government seeks to protect consists of a vulnerable group of the general population who warrant extra protection from corrupt decision-making.

2.  Antitrust

A possible counterargument to the use of this burden-shifting framework is that it is only appropriate when a federal statute guides the court to do so. Without a statute providing a court with direction to contemplate a burden-shifting framework, it remains out of the court’s purview to make use of such a framework. However, allocating burdens can be influenced by “specific policy concerns, convenience, and access to relevant evidence,”162 all pertinent factors in AKS litigation. Lessons from analogous burden-shifting doctrines in antitrust law point to how worries of possible over prosecution can be subsided.

Many antitrust cases apply the “rule of reason,” which is a legal analysis used by courts to determine whether a business practice has a significant anticompetitive effect on the market and whether there are any procompetitive justifications.163 Courts have interpreted this rule of reason to allow for the burden of proof to shift between plaintiffs and defendants in certain contexts. Known as the Baker Hughes framework,164 courts use this burden-shifting framework in merger challenges when the plaintiff has demonstrated evidence of likely anticompetitive effects.165 Once the plaintiff has successfully established a prima facie presumption that the transaction will lessen competition, the burden then shifts to the defendant to undermine the plaintiff’s evidence.166 The defendant can point to entry, efficiencies, or the financial condition of both merging parties.167 The burden then shifts back to the plaintiff for the judge to evaluate the strength of the plaintiff’s overall case as to anticompetitive effects.168 Important to highlight in this framework, is that the burden of proof remains with the plaintiff while the burden of production is what shifts between plaintiff and defendant.169 In analyzing complex business transactions and using a burden-shifting framework, courts have signaled that “[t]he search for clarity . . . does not mean . . . that courts should default to heightened burdens on plaintiffs . . . which would systematically favo[]r defendants.”170 Thus, a burden-shifting framework is not an attempt at taking all the burden off the plaintiff. Instead, it’s used as a way to just shift that evidentiary burden onto a defendant who would typically be systematically favored in AKS-predicated FCA litigation.

3.  Fiduciary duties

Another example arises in cases where a fiduciary duty exists between the defendant and plaintiff. Pertinent to cases predicated on AKS-violations, “the patient-physician relationship fits this description well: the patient usually lacks medical expertise, making them dependent on the physician’s knowledge and judgment.”171 Fiduciary relationships may arise by “statute, contract, conduct, or a confidential relationship”172 and essentially ensure that the person with the duty act in the best interests of the beneficiary. Fiduciaries are typically understood to have been “entrusted with power over the legal or practical interests of another person (the beneficiary).”173 In cases alleging that a fiduciary duty was breached, the plaintiff must demonstrate “(1) the existence of a fiduciary duty, (2) breach of that fiduciary duty, and (3) damages directly stemming from that breach.”174 If the defendant has profited or benefitted from the transaction, the burden then shifts to them to prove that they acted in good faith and “did not use the advantage of his or her position to gain any benefit for himself or herself.”175 Rather than focus on the lack of evidence that one party might have over the other, unlike in employment discrimination cases, this group of cases focuses on the duty that professionals owe to their clients and patients.            

Similar to fiduciary duty cases, there is a clear duty that healthcare professionals owe to their patients ensuring that they receive honest, non-corrupt medical advice, procedures, and prescriptions. Thus, it seems possible to reframe AKS violations as a breach to patients, victim to kickback schemes, who suffered from a breach of duty and loyalty from their healthcare professionals. Just as in fiduciary breach cases where the burden shifts “to the defendant to prove that the same loss would have occurred in the absence of, or ‘but-for,’ the unlawful act,”176 the same principle can be applied to AKS cases to ensure that the defendant can prove that the false claim was not but-for the alleged kickback.

B.  Why Burden-Shifting Best Solves the AKS Causation Issue

The use of this burden-shifting framework would remain in line with the decisions as held by the Sixth, Eighth, and First Circuits in ensuring that the defendant can contest evidence presented by the government. The district court in Regeneron argued that “[t]he Greenfield opinion . . . effectively bars the defendant from contesting the government’s evidence of causation once an AKS violation is proved.”177 Under a burden-shifting framework, “the defendant . . . is not required to allege and prove the specific cause of the injury.”178 Thus, a pharmaceutical company would still be afforded the opportunity to contest the alleged kickback scheme presented by the government. Additionally, the circuits proposing a but-for causation standard might be more inclined to accept a burden-shifting framework as it seems to reach a middle ground between the Greenfield and Cairns standards. The court in Hathaway feared that absent a but-for causation standard, the government would be able to prosecute even earnest attempts at non-corrupt medical care.179 However, introducing a burden-shifting doctrine would allow for defendants to rebut a presumption of an alleged kickback scheme while still making it more feasible for plaintiffs to bring sufficiently convincing evidence in the first place, without fear of losing at the summary judgment stage.

It is especially important to consider this type of framework if but-for causation remains the majority rule in the circuits, as potentially indicated by the First Circuit’s decision in Regeneron. The benefit of applying such a framework comes from the need to fill gaps that current rules leave unresolved. But applying a burden-shifting framework doesn’t make sense in every situation. In environmental disaster cases where defendants’ actions have contributed to long-term ecological injuries which present complicated efforts to prove causation, the notion of a using a burden-shifting framework has been suggested.180 The California Supreme Court, however, has “concluded that a burden-shifting instruction was unnecessary given that the plaintiff could satisfy the substantial factor test by simply showing that the defendant’s product contributed in some way to the increased risk of injury.”181 There the court pointed out that with a substantial factor requirement in place, somewhat similar to Greenfield’s lower causation requirement, the evidentiary requirement was much less substantial. However, the AKS cases in question do not abide by a “substantial factor” test and instead necessitate a much greater evidentiary burden. If courts are going to require but-for causation, they must be willing to shift the burden of proof to the defendant.

The AKS is a criminal statute and so it understandably begs the question—should it require a more stringent causation standard, making it harder for the government to prosecute false claims predicated on an AKS violation?182 With resulting criminal and civil charges, it is understandable why courts are hesitant to permit arbitrary prosecutorial discretion on behalf of the government. Additionally, courts need to be concerned about the issue of fair notice. A loose causation requirement could draw in conduct that individuals do not have reasonable grounds to believe would fall under the statute. A but-for causation requirement, however, might swing the pendulum too far in the other direction in the context of AKS litigation. If courts were to reassess their current causation standards through the lens of evidentiary burdens, the result could be one that allows for a more stringent causation requirement while leveling the playing field between both parties.

The need to evaluate the evidentiary burden placed on the plaintiff under a but-for causation standard stems directly from the statutory language in the AKS. The AKS seeks to target numerous remunerations including “any kickback” either “directly or indirectly, overtly or covertly, in cash or in kind.”183  None of the circuits to rule on this issue have provided sufficient guidance on what kind of evidence, either direct or circumstantial, the government will be required to show if a kickback is overt and in kind. The truth of the matter is that “[a]bsent a written or verbal admission from the defendant, it is not clear how a plaintiff might show that certain care would not have been provided if not for a kickback.”184 The difficulty that could arise for a plaintiff to successfully demonstrate that a claim would have not been submitted but-for the remuneration, seems like an area to introduce a burden-shifting framework to better afford the plaintiff an opportunity to bring forth substantial evidence, while still giving the defendant the option to rebut the initial presumption.

The district court in Regeneron raised the concern that “[t]he Greenfield opinion also effectively bars the defendant from contesting the government’s evidence of causation once an AKS violation is proved.”185 The court in Greenfield did not address the evidentiary burden placed on the defendant and the district opinion in Regeneron pointed out that proof of a link “becomes akin to an irrebuttable presumption,”186 implying that maybe defendants should have the opportunity to rebut a proven AKS violation. After addressing the evidentiary concerns in a court that abides by the “mere link” rule, the district court spent ample time discussing the evidentiary hurdles government would need to prove in a but-for causation regime. The court’s discussion starts by clarifying that the government’s burden would not be made insuperably difficult and the government would need only prove “that it was more likely than not that the AKS violation was the cause of the false claim.”187 Again, however, the court failed to lay out specific evidentiary requirements and instead, claimed that the government can attempt to prove its case through circumstantial evidence and reasonable inferences.188 While the district court alluded to these evidentiary difficulties, the First Circuit seemed to toss those arguments to the side and instead relied heavily on the fact that litigants could still be able to bring an FCA claim under the false-certification theory and aimed to clearly distinguish that theory from reliance on the 2010 amendment.189

While the First, Third, Sixth, and Eighth Circuits have each settled on different causation standards, there is ample room to analyze the practical evidentiary effects of both causation regimes. Litigation with substantial evidentiary burden issues often results in courts making underlying assumptions that a single factor can fully explain the issue at hand, often ignoring the complexities entangled in a kickback scheme.

C.  Case Study

Applying a burden-shifting framework to the Insys case study can help paint a clearer picture as to how this theory would apply. Imagine a plaintiff starts researching Subsys after her doctor prescribes it to her claiming that it would help with her chronic back pain. She realizes that Subsys only has FDA approval for patients currently undergoing cancer treatment, a category she does not fall under. She has a history of addiction in her family and worries about the long-term effects this could have on her health. After learning more about Insys’s previous activity of engaging in alleged kickback schemes, she brings a qui tam lawsuit against Insys claiming that they paid her physician unlawful kickbacks to induce him to unnecessarily prescribe Subsys to non-cancer patients. Her case is brought in the Sixth Circuit, requiring her to prove that but-for the illegal kickback, her doctor wouldn’t have submitted a claim to Medicare and she wouldn’t have been prescribed Subsys.

The plaintiff would start by pointing to scientific evidence that Subsys is typically only prescribed to patients going through cancer treatment and that her doctor had never mentioned this drug until recently, even though she has suffered from chronic back for years. This is where the information asymmetry and evidentiary burden comes into play—what evidence will be sufficient for a court to rule that but-for the illegal kickback her doctor received, she wouldn’t have been prescribed Subsys? The practical consequences of this burden-shifting framework would allow the plaintiff to first offer sufficient evidence to establish a violation of the AKS. Then, the defendant would have the opportunity to rebut this presumption and prove that either there was no remuneration to begin with or demonstrate that the kickback was not connected to the subsequent claim and prescription. Lastly, the burden would shift once more, as the plaintiff bears the ultimate burden of persuasion. The onus would ultimately fall on her to evaluate the strength of Insys’s overall case regarding the kickback scheme. This case study offers a picture as to how a burden-shifting framework could ultimately help resolve issues around evidentiary burdens and fairness concerns for both plaintiffs and defendants.

V.  Conclusion

Since the enactment of the FCA and the AKS, both statutes have been used to combat healthcare fraud and ensure that patients under federal healthcare programs are not receiving unethical medical care. While the 2010 amendment initially sought to make it so that any claim tainted by a kickback was deemed to be necessarily false, courts have born the responsibility of interpreting how strong the link must be between the alleged kickback and the subsequent false claim made under Medicare or Medicaid.

The First, Sixth, and Eighth Circuits have opted for a but-for causation standard given the ordinary meaning of “resulting from” and the fear that anything less than but-for could result in over prosecution of harmless activity. The Third Circuit, on the other hand, held that the government need only show that there is evidence connecting a kickback and a subsequent payment. While the easiest answer may be for the Supreme Court to fall on one side of the debate, the best way to resolve this circuit split is not through competing textual interpretations, but by focusing on the evidentiary burdens each causation standard places on plaintiffs and defendants. Courts should consider the practical effects that each causation standard would have on future litigation. Evaluating the evidentiary burdens—an area only lightly touched upon by the circuits—opens the door to a more nuanced and equitable framework.

In cases marked by a significant information asymmetry between the parties, a burden-shifting framework can resolve those issues while still ensuring that both sides are forced to bear the evidentiary burden. By looking at other legal contexts in which a burden-shifting framework has proved effective including, employment discrimination cases, merger challenges in antitrust cases, and cases in which a fiduciary duty exists between the plaintiff and defendant, all these examples demonstrate how, in certain contexts, a burden-shifting framework can prove effective in combating evidentiary vacuums. The current circuit split over causation standards in AKS predicated FCA violations creates significant evidentiary challenges, with but-for causation making it difficult for the government to prove their case while the more lenient standard in Greenfield may unfairly prevent defendants from contesting government allegations. A burden-shifting framework could resolve this tension by requiring plaintiffs to establish a prima facie case of kickback-related harm, allowing defendants to rebut this presumption, before the onus ultimately relies on the plaintiff to prove its case. This approach better balances the evidentiary playing field while maintaining appropriate protections against prosecutorial overreach.

Healthcare fraud is particularly devasting because it undermines the integrity of the healthcare system, diverts critical resources from patients who truly need care, and drives up costs for taxpayers and beneficiaries of the country’s robust federal health care programs alike. When fraudulent claims predicated on AKS violations are submitted to federal programs, not only is public funding misuses, but trust in these programs is also eroded. Moreover, healthcare fraud often results in the delivery of unnecessary or even harmful treatments, as was demonstrative in the Insys kickback, damaging the lives of thousands of patients. In its most egregious forms, healthcare fraud can incentivize profit-driven decisions over patient well-being. In a but-for causation regime, plaintiffs are put at a disadvantage if they do not have access to smoking gun evidence that will show but-for causation between a kickback and subsequent claim to a federal program. On the other hand, defendants are disadvantaged if all that is required to prove liability is some link between a payment of a kickback and a subsequent claim. A burden-shifting framework seeks to resolve those discrepancies and to act as a solution more responsive to the practical effects of litigation by leveling the playing field between both parties.

• 1Benjamin Weiser & Katie Thomas, 5 Doctors Are Charged with Taking Kickbacks for Fentanyl Prescriptions, N.Y. Times (Mar. 16, 2018), https://www.nytimes.com/2018/03/16/nyre‌g‌i‌o‌n‌/‌fentanyl-subsys-drug-kickbacks.html [perma.cc/F2VG-8HS3].
• 2Barbara Benham & Robin Scullin, Archive Shows How Fentanyl Promotion Helped Drive Opioid Epidemic, Johns Hopkins Bloomberg Sch. Pub. Health (Dec. 8, 2022), https://publichealth.jhu.edu/2022/archive-shows-how-fentanyl-promotion-helped-drive-opioid-epidemic [perma.cc/HYS2-YEXL].
• 3Weiser & Thomas, supra note 1.
• 4Id.
• 5Press Release, U.S. Att’y’s Off., S.D.N.Y., Manhattan Doctor Sentenced to More Than 17 Years in Prison for Bribery and Kickback Scheme, and for Distributing Oxycodone and Fentanyl for No Legitimate Medical Purpose (July 8, 2021), https://www.justice.gov/usao-sdny/pr/manhatt‌a‌n‌-‌doctor-sentenced-more-17-years-prison-bribery-and-kickback-scheme-and ‌[‌p‌e‌r‌m‌a‌.‌c‌c‌/‌7‌U‌‌A‌‌‌‌N‌-‌2‌8‌D‌P‌].
• 6Weiser & Thomas, supra note 1.
• 7Press Release, U.S. Dep’t of Just., Opioid Manufacturer Insys Therapeutics Agrees to Enter $225 Million Global Resolution of Criminal and Civil Investigations (June 5, 2019) [hereinafter Insys Therapeutics Settlement], https://www.justice.gov/opa/pr/opioid-manufacturer-insys-therapeutics-agrees-enter-225-million-global-resolution-criminal [perma.cc/R8UP-8XZV].
• 8Id.
• 9Id.
• 10Id.
• 11Id.
• 12Id.; see also Katie Thomas, Doubts Raised About Off-Label Use of Subsys, a Strong Painkiller, N.Y. Times (May 13, 2014), https://www.nytimes.com/2014/05/14/business/doubts-raised-about-off-label-use-of-subsys-a-strong-painkiller.html [perma.cc/8HXH-YU58] (statement of Dr. Sidney M. Wolfe) (“You’re essentially spreading the accessibility to a very potent, rapid-onset narcotic to a large number of people, and a number of them may get addicted.”).
• 13Insys Therapeutics Settlement, supra note 7.
• 14Benham & Scullin, supra note 2.
• 15See, e.g., Press Release, U.S. Dep’t of Just., United States Files False Claims Act Complaint Against Chiropractor, Modern Vascular Office-Based Labs and Modern Vascular Corporate Entities (Dec. 13, 2022), https://www.justice.gov/archives/opa/pr/united-states-files-false-claims-act-‌c‌o‌m‌p‌l‌aint-against-chiropractor-modern-vascular-office [perma.cc/B2C2-K2N5] (“The ‌U‌n‌i‌ted ‌States’ complaint alleges that from at least Jan. 1, 2018, through June 30, 2022, Gampel and the Modern Vascular defendants offered physicians the opportunity to invest in Modern Vascular office-based labs to induce them to refer their Medicare and TRICARE patients to Modern Vascular for the treatment of peripheral arterial disease.”); see also Press Release, U.S. Dep’t of Just., Carter Healthcare Affiliates and Two Senior Managers to Pay $7.175 Million to Resolve False Claims Act Allegations for False Florida Home Health Billings (Oct. 18, 2022), https://www.justice.gov/archives/opa/pr/carter-healthcare-affiliates-and-two-senior-managers-pay-7175-million-resolve-false-claims [perma.cc/VPM8-5NWF] (“Between 2014 and 2016, Carter Healthcare allegedly billed the Medicare Program knowingly and improperly for home healthcare to patients in Florida based on therapy provided without regard to medical necessity and overbilled for therapy by upcoding patients’ diagnoses.”); Press Release, U.S. Dep’t of Just., Modernizing Medicine Agrees to Pay $45 Million to Resolve Allegations of Accepting and Paying Illegal Kickbacks and Causing False Claims (Nov. 1, 2022), https://www.justice.gov/archives/opa/pr/modernizing-medicine-‌a‌g‌r‌ees-pay-45-million-resolve-allegations-accepting-and-paying-illegal ‌[‌‌p‌e‌r‌m‌a‌.‌c‌c‌/‌T‌S‌9‌7‌-JGSY] (“Modernizing Medicine Inc. (ModMed), an electronic health record (EHR) technology vendor located in Boca Raton, Florida, has agreed to pay $45 million to resolve allegations that it violated the False Claims Act (FCA) by accepting and providing unlawful remuneration in exchange for referrals and by causing its users to report inaccurate information in connection with claims for federal incentive payments.”).
• 1631 U.S.C. § 3729(a)(1).
• 17The False Claims Act, Nat’l Whistleblower Ctr., https://www.whistleblowers.org/pro‌t‌e‌c‌t‌-the-false-claims-act/ [perma.cc/B3CQ-DWHX].
• 1842 U.S.C. § 1320a-7b(b)(1)(A).
• 1942 U.S.C. § 1320a-7b(b)(1).
• 20Anti-Kickback Statute and Stark Law, Constantine Cannon, https://constantinecan‌n‌o‌n‌.‌com/practice/whistleblower/whistleblower-types/healthcare-fraud/anti-kickback-stark/ ‌[‌‌p‌e‌r‌m‌a‌.‌c‌c‌/‌Z‌L‌4N-HBS7].
• 21David W.S. Lieberman, AKS – Anti Kickback Statute Explained, Whistleblower L. Collaborative (Jan. 9, 2024), https://www.whistleblowerllc.com/anti-kickback-statute/ [‌‌p‌e‌r‌ma‌.‌c‌c‌/‌6‌K5G-Y7AU].
• 22Lauren Rutkowski, “Resulting from” Unclear Language: Why Congress Must Amend the Anti-Kickback Statute to Clarify Its Intent to Hold Violators Accountable and Recover Fraud-Based Payments, 54 Seton Hall L. Rev. 819, 821 (2024).
• 23See, e.g., United States ex. rel Greenfield v. Medco Health Sols., Inc., 880 F.3d 89, 95 (3d Cir. 2018) (“At issue, therefore, is what ‘link’ is sufficient to connect an alleged kickback scheme to a subsequent claim for reimbursement: a direct causal link, no link at all, or something in between.”); see also United States ex rel. Martin v. Hathaway, 63 F.4th 1043 (6th Cir. 2023), cert. denied, 144 S. Ct. 224 (2023); United States ex rel. Cairns v. D.S. Medical LLC, 42 F.4th 828, 834 (8th Cir. 2022) (“Now on to what the district court got wrong: causation. The jury instruction said ‘it is enough for the United States to show that the claim failed to disclose the [a]nti-[k]ickback [s]tatute violation.’ This instruction, which brushed aside causation, misinterpreted the 2010 amendment.”); United States v. Regeneron Pharms. Inc., 128 F.4th 324, 330 (1st Cir. 2025) (“Hence, the question posed here is whether the type of actual causality required is (as in ordinary course) but-for causation.”).
• 24See, e.g., Compliance Implications for Healthcare Companies Post-First Circuit Decision, Cooley LLP (May 15, 2025), https://investigations.cooley.com/2025/05/15/compliance-implications-for-healthcare-companies-post-first-circuit-decision/ [perma.cc/9ZPW-YSYQ].
• 25Avia M. Dunn, et al., First Circuit Demands ‘But For’ Causation Between Alleged Kickback and Claim Submission, Skadden, Arps, Slate, Meagher & Flom LLP (Feb. 24, 2025), ‌h‌t‌t‌p‌s‌:‌/‌/‌www.skadden.com/i‌n‌s‌ights/publications/2025/02/first-circuit-demands [‌p‌e‌r‌m‌a‌.‌c‌c‌/‌G‌3‌3‌A‌-‌X‌V‌Y‌M].
• 26First Circuit Affirms Causation Defense for False Claims Act Based on AKS Violations, Debevoise & Plimpton (Mar. 3, 2025), https://www.debevoise.com/insights/publica‌t‌i‌o‌n‌s‌/‌2‌0‌2‌5‌/‌0‌3‌/‌f‌i‌rst-circuit-affirms-causation-defense-for-false [perma.cc/6VCF-TF6C].
• 27Id.
• 28Greenfield, 880 F.3d at 100.
• 29Timothy Fry & Brett Barnett, The Growing Causal Divide: But-For Causation in AKS/FCA Actions, FCA Insider (Dec. 1, 2023), https://www.thefcainsider.com/2023/12/the-growing-causal-‌d‌i‌v‌ide-but-for-causation-in-aks-fca-actions/ [perma.cc/ZXQ3-TGLP].
• 30See generally Jessica L. Parillo, Prescribing the Right Causation Standard: The Sixth Circuit’s Approach to Holding Healthcare Fraudsters Civilly Liable, 65 B.C. L. Rev 2213 (2024); Alexandra Wildman, Bridging the False Certification Gap: Why “Resulting From” in the 2010 AKS Amendment Requires But-For Causation, 93 Fordham L. Rev. 359 (2024); Maria Russo, Eye for An Eye? The Sixth Circuit Loses Sight of Anti-Kickback Causation in Hathaway, 65 B.C. L. Rev. 2249 (2024).
• 31Jeff Overley, 50 Years in, Industry Has Knives out for Potent Kickback Law, Law360 (Mar. 18, 2023), https://www.law360.com/articles/1570400/50-years-in-industry-has-knives-out-for-pote‌n‌t‌-‌kickback-law [perma.cc/RJ9E-BK3L].
• 32Marc S. Raspanti, A Practitioner’s Primer on History and Use of the Federal Anti-Kickback Statute, Pietragallo (Mar. 28, 2017), https://www.pietragallo.com/publications/a-practitioners-primer-on-history-and-use-of-the-federal-anti-kickback-statute/ [perma.cc/6LH8-6U3A].
• 33Id.
• 34Id.
• 35Fraud and Abuse Laws, Off. Inspector Gen., https://oig.hhs.gov/compliance/physician-ed‌u‌c‌a‌tion/fraud-abuse-laws/ [perma.cc/6CDE-ETNE].
• 3642 U.S.C. § 1320a-7b(b)(1).
• 37Insys Therapeutics Settlement, supra note 7.
• 38Lieberman, supra note 21.
• 39Katherine Keisler-Starkey & Lisa N. Bunch, U.S. Census Bureau, Health Insurance Coverage in the United States: 2023 3 (2024).
• 40Overley, supra note 31 (statement of Robert D. McCallum Jr.) (“Health care providers ‘hold a public trust, and when that trust is violated by . . . the payment of kickbacks to the physicians on whom patients and the programs rely for uncompromised medical judgment, health care for all Americans suffers.’”).
• 41Id.
• 42See, e.g., id.; see also United States v. Greber, 760 F.2d 68, 70–71 (3d Cir. 1985) (“Congress, concerned with the growing problem of fraud and abuse in the system, wished to strengthen the penalties to enhance the deterrent effect of the statute. To achieve this purpose, the crime was upgraded from a misdemeanor to a felony.”).
• 4342 U.S.C. § 1320a-7b(b)(1)(A).
• 44760 F.2d 68 (3d Cir. 1985).
• 45Id. at 70.
• 46Id.
• 47Id.
• 48Id. at 71.
• 49Id. at 69 (emphasis added).
• 50604 F.2d 999 (7th Cir. 1979).
• 51Greber, 760 F.2d at 71; see alsoid. at 72 (“The potential for increased costs to the Medicare-Medicaid system and misapplication of federal funds is plain, where payments for the exercise of such judgments are added to the legitimate cost of the transaction . . . [T]hese are among the evils Congress sought to prevent by enacting the kickback statutes.” (alteration in original) (citing Hancock, 604 F.2d at 1001)).
• 52Id. at 71.
• 53Id. at 72.
• 54Id.
• 55The False Claims Act, U.S. Dep’t Just. (Jan. 15, 2025) [hereinafter The False Claims Act], https://www.justice.gov/civil/false-claims-act [perma.cc/LJ4E-Y774].
• 56Mike Bothwell, False Claims Act Violation Examples, Bothwell L. Grp., https://whistleb‌l‌o‌w‌erlaw.com/examples-false-claims-act-violations/ [perma.cc/HXS5-7MU3].
• 57The False Claims Act, Nat’l Whistleblower Ctr., https://www.whistleblowers.org/protect-the-false-claims-act/ [perma.cc/42MU-NMRN]; see also Press Release, U.S. Dep’t of Just., Justice Department Recovers over $2.8 Billion from False Claims Act Cases in Fiscal Year 2018 (Dec. 21, 2018), https://www.justice.gov/archives/opa/pr/justice-department-recovers-over-28-billion-‌f‌a‌l‌s‌e-‌c‌l‌aims-act-cases-fiscal-year-2018 [perma.cc/54U6-DNHW] (“Back then, crooked contractors defrauded the Union Army by selling it sick mules, lame horses, sawdust instead of gunpowder, and rotted ships with fresh paint.”).
• 58The False Claims Act, supra note 55.
• 59See, e.g., Nathan T. Tschepik, The Executive Judgment Rule: A New Standard of Dismissal for Qui Tam Suits Under the False Claims Act, 87 U. Chi. L. Rev. 1051 (2020).
• 60Id. at 1060.
• 61Rutkowski, supra note 22.
• 62155 Cong. Rec. S10853 (2009).
• 63Id.
• 64Id.
• 6542 U.S.C. § 1320a-7b(g).
• 6642 U.S.C. § 1320a-7b(h).
• 67Overley, supra note 31; see also Press Release, U.S. Dep’t of Just., False Claims Act Settlements and Judgments Exceed $2.68 Billion in Fiscal Year 2023 (Feb. 22, 2024) [hereinafter Settlements Exceed $2.68 Billion], https://www.justice.gov/archives/opa/pr/false-claims-act-settlements-and-judgments-exceed-268-billion-fiscal-year-2023 [perma.cc/C3DA-RDG9] (noting that the 543 settlements and judgments under the False Claims Act in the 2023 fiscal year cumulatively exceeded $2.68 billion, also setting the record for the highest number of settlements and judgments in a single year).
• 68Noam B. Fischman et al., False Claims Act Enforcement Trends in Healthcare: FY 2024, Akerman (Feb. 4, 2025), https://www.akerman.com/en/perspectives/hrx-false-claims-act-enforcement-trends-in-healthcare-fy-2024.html [perma.cc/B9UW-XSUJ] (“[H]ealthcare has consistently been a primary target of FCA enforcement and represents 69% of overall recoveries since 1987 at $54 billion.”).
• 69Id.
• 70Overley, supra note 31.
• 71Settlements Exceed $2.68 Billion, supra note 67 (including a statement by Former Acting Associate Attorney General Benjamin C. Mizer in which he states that “[p]rotecting taxpayer dollars from fraud and abuse is of paramount importance to the Department of Justice . . . [t]he False Claims Act remains one of our most important tools for rooting out fraud, ensuring that public funds are spent properly, and safeguarding critical government programs”).
• 72155 Cong. Rec. S10854 (2009).
• 73Rutkowski, supra note 22, at 834.
• 7442 U.S.C. § 1320a-7b(g).
• 75Mara Sanders & Hannah McCallum, The False Claims Act and the Anti-Kickback Statute: Causation, Materiality, and the Connection Between the Two, Dorsey & Whitney LLP (July 11, 2024), https://www.dorseyhealthlaw.com/the-false-claims-act-and-the-anti-kickback-statute-cau‌s‌a‌t‌i‌on-materiality-and-the-connection-between-the-two/ [perma.cc/46QJ-F7D2].
• 76First Circuit Affirms Causation Defense for False Claims Act Based on AKS Violations, supra note 26.
• 77See United States ex. rel Greenfield v. Medco Health Sols., Inc., 880 F.3d 89 (3d Cir. 2018).
• 78128 F.4th 324 (1st Cir. 2025).
• 79Highly Anticipated First Circuit Opinion on AKS Causation in FCA Cases Brings Hope for Defendants – But Also Muddies the Waters, Gibson Dunn (Feb. 20, 2025), https://www.gibsondunn.com/highly-anticipated-first-circuit-opinion-on-aks-causation-in-fca-cases-brings-hope-for-defendants-but-also-muddies-the-waters/ [perma.cc/D39P-AX99] (“The [Supreme] Court has taken up an FCA-related case in most terms in recent memory; and the Court has previously agreed to take up cases like Burrage and Paroline,” which are both heavily cited decisions in the Circuits’ decisions.).
• 8042 F.4th 828 (8th Cir. 2022).
• 81Id. at 831.
• 82Id.
• 83Id.
• 84Id.
• 85Id.
• 86Cairns, 42 F.4th at 831.
• 87Id. at 834.
• 88Id.
• 89571 U.S. 204 (2014).
• 90Id. at 206.
• 91Cairns, 42 F.4th at 834.
• 92Id. at 835.
• 93Id.
• 94Id. at 836.
• 95Id.
• 9642 U.S.C. § 1320a-7b(g).
• 9763 F.4th 1043 (6th Cir. 2023), cert. denied, 144 S. Ct. 224 (2023).
• 98Id. at 1047.
• 99Id. (citing United States ex rel. Ibanez v. Bristol-Myers Squibb Co., 874 F.3d 905, 914 (6th Cir. 2017)).
• 100Id. at 1048.
• 101Id. at 1049.
• 102Id. at 1051.
• 103Hathaway, 63 F.4th at 1052.
• 104Id. at 1055.
• 105Id.
• 106128 F.4th 324 (1st Cir. 2025).
• 107682 F. Supp. 3d 142 (D. Mass. 2023).
• 108No. 20-11217, 2023 WL 7016900 (D. Mass. Oct. 25, 2023).
• 109Teva, 682 F. Supp. 3d at 148.
• 110Regeneron, 2023 WL 7016900, at *12.
• 111Pablo Davis, First Circuit Poised to Consider Anti-Kickback Statute’s Causation Element in FCA Cases, Take a Position on Circuit Split, JD Supra (June 28, 2024), https://www.jdsu‌p‌r‌a‌.‌c‌o‌m‌/‌legalnews/first-circuit-poised-to-consider-anti-3214066/ [perma.cc/2G3D-73VV].
• 112Press Release, U.S. Dep’t of Just., Drug Maker Teva Pharmaceuticals Agrees to Pay $450M in False Claims Act Settlement to Resolve Kickback Allegations Relating to Copayments and Price Fixing (Oct. 10, 2024), https://www.justice.gov/opa/pr/drug-maker-teva-pharmaceuticals-agrees-‌p‌a‌y‌-450m-false-claims-act-settlement-resolve-kickback [perma.cc/2XZ7-LTL8].
• 113United States v. Regeneron Pharms., Inc., 128 F.4th 324, 326 (1st Cir. 2025).
• 114Id.
• 115Id. at 327.
• 116Id.
• 117United States v. Regeneron Pharms., Inc., No. 20-11217, 2023 WL 7016900 at *11–14 (D. Mass. Oct. 25, 2023).
• 118Id. at *13 (“It does not necessarily follow, however, that the government’s burden is thereby made insuperably difficult.”).
• 119Id.
• 120Id.
• 121Regeneron, 128 F.4th at 330 (“A ‘textual’ indication draws on the plain text of the statute’s causation language, while a ‘contextual’ indication arises from the substance or structure of the statutory scheme as a whole.”).
• 122Id.
• 123Fault Lines Expected to Deepen: Major False Claims Act Circuit Split, Proskauer Rose LLP (Oct. 11, 2024), https://www.proskauer.com/blog/fault-lines-expected-to-deepen-major-false-c‌l‌a‌i‌ms-act-circuit-split [perma.cc/43C7-D6SJ].
• 124Regeneron, 128 F.4th at 331.
• 125Id.
• 126Id. at 332.
• 127Id. at 333.
• 128Id. at 335.
• 129United States ex. rel Greenfield v. Medco Health Sols., Inc., 880 F.3d 89, 100 (3d Cir. 2018).
• 130Id. at 91.
• 131Id. at 92.
• 132Id. at 95.
• 133Id. at 98.
• 134Id. at 96–97.
• 135Greenfield, 880 F.3d at 97.
• 136Id.
• 137See Michelle Foster, Causation in Context: Interpreting the Nexus Clause in the Refugee Convention, 23 Mich. J. Int’l L. 265, 317 (2022) (analyzing the nexus clause in the refugee convention and arguing for the necessity of a broad and flexible causation standard to ensure appropriate restitution for plaintiffs).
• 138Rutkowski, supra note 22, at 823.
• 139Id.
• 140United States ex rel. Cairns v. D.S. Medical LLC, 42 F.4th 828, 836 (8th Cir. 2022).
• 141Greenfield, 880 F.3d at 95.
• 142United States ex rel. Martin v. Hathaway, 63 F.4th 1043, 1054–55 (6th Cir. 2023), cert. denied, 144 S. Ct. 224 (2023).
• 143See Travis R. Linn, Snitches Get Stitches: An Analysis of the Eighth Circuit’s But-For Causation Requirement in False Claims Act Litigation “Resulting From” Anti-Kickback Violations, 76 Ark. L. Rev. 595, 623 (2023).
• 144Id. at 616.
• 145Id. at 615.
• 146See United States ex rel. Cairns v. D.S. Medical LLC, 42 F.4th 828, 836 (8th Cir. 2022) (“After all, when a statute is unambiguous, we start and end in the same place: with the words of the statute itself.”); see also Hathaway, 63 F.4th at 1053 (“Where a statute ‘yields a clear answer, judges must stop.’” (citing Food Mktg. Inst. v. Argus Leader Media, 588 U.S. 427, 436 (2019))).
• 147United States v. Regeneron Pharms., Inc., 128 F.4th 324, 335 (1st Cir. 2025).
• 148Id.
• 149United States ex. rel Greenfield v. Medco Health Sols., Inc., 880 F.3d 89, 100 (3d Cir. 2018).
• 150Id. at 96 (“It appears the drafters of the Anti-Kickback Statute intended ‘to strengthen the capability of the Government to detect, prosecute, and punish fraudulent activities under the [M]edicare and [M]edicaid programs,’ . . . because ‘fraud and abuse among practitioners . . . is relatively difficult to prove and correct.’” (citing H.R. Rep. No. 95-393, pt. 1, at 1 (1977); H.R. Rep. No. 95-393, pt. 2, at 47 (1977))).
• 151Shifting the Burden of Proof, Cornell L. Sch. Legal Info. Inst. (July 2021), ‌h‌t‌t‌p‌s‌:‌/‌/‌w‌w‌w‌.‌law.cornell.edu/wex/shifting_the_burden_of_proof [perma.cc/A3WL-54XA].
• 152This framework is named after McDonnell Douglas Corp. v. Green, 411 U.S. 792 (1973).
• 153Thallia Malespin, The Proof Is in the New Pudding: The Third Circuit Removes “But-for” Causation from the Prima Facie Case for Title VII Retaliation Claims in Carvalho-Grevious v. Delaware State University, 63 Vill. L. Rev. 803, 810–11 (2019).
• 154Richard A. Hill, Credit Opportunities, Race, and Presumptions: Does the McDonnell Douglas Framework Apply in Fair Lending Cases?, 64 Mo. L. Rev. 479, 499–500 (1999).
• 155See Foster, supra note 137, at 327.
• 156McDonnell Douglas, 411 U.S. at 802.
• 157Id.
• 158U.S. E.E.O.C. v. Target Corp., 460 F.3d 946, 957 (7th Cir. 2006).
• 159Texas Dep’t of Cmty. Affs. v. Burdine, 450 U.S. 248, 253 (1981).
• 160See, e.g., Jenny R. Yang & Jane Liu, Strengthening Accountability for Discrimination, Econ. Pol’y Inst. (Jan. 15, 2021), https://www.epi.org/unequalpower/publications/strengthening-accountability-for-discrimination-confronting-fundamental-power-imbalances-in-the-employment-relationship/ [perma.cc/U8H7-A5Z8] (“Further exacerbating this problem, workers must contend with gross asymmetries of information and power as compared to employers, a situation that often creates insurmountable barriers for employees to raising complaints. The operation of anti-discrimination laws and institutional structures fail to confront these vast information and power imbalances; instead, they often act to tip the scales further in favor of employers.”).
• 161Linn, supra note 143, at 607.
• 162Andrew I. Gavil, Burden of Proof in U.S. Antitrust Law, 1 Issues Competition L. & Pol’y 125, 127 (2008).
• 163Elements of the Offense, U.S. Dep’t Just., https://www.justice.gov/archives/jm/antitrust-re‌s‌‌o‌‌‌u‌‌r‌ce-manual-1-attorney-generals-policy-statement [perma.cc/Z3NN-DXYJ].
• 164This framework is named after United States v. Baker Hughes Inc., 908 F.2d 981 (D.C. Cir. 1990).
• 165Gavil, supra note 162, at 149.
• 166Id.
• 167Id. at 148; see also FTC & DOJ Propose Radical Changes to Merger Guidelines, Cleary Gottlieb (July 24, 2023), https://www.clearyantitrustwatch.com/2023/07/ftc-doj-propose-radical-changes-to-merger-guidelines/ [perma.cc/H9W4-NDE5].
• 168Gavil, supra note 162, at 149.
• 169Id. at 151.
• 170Id. at 156.
• 171Sophie Ludewigs et al., Ethics of the Fiduciary Relationship Between Patient and Physician: The Case of Informed Consent, 51 J. Med. Ethics 59 (Dec. 8, 2022), https://jme.bmj.com/content/51/1/59 [https://doi.org/10.1136/jme-2022-108539].
• 172Michael W. Stockham & Mackenzie S. Wallace, Fiduciary Duty Litigation and Burden Shifting, ABA (Mar. 4, 2014), https://www.hklaw.com/files/tklaw/wp-content/upl‌o‌a‌d‌s‌/‌2‌0‌1‌9‌/‌0‌2‌/‌2‌5‌1‌3‌0619/Fiduciary-Duty-Litigation-and-Burden-Shifting-_-Trial-Evidence-Committee-_-A.pdf [perma.cc/9MAN-FFEC].
• 173Ludewigs et al., supra note 171.
• 174Stockham & Wallace, supra note 172.
• 175Id.
• 176Robert A. Kearney, Why the Burden of Proving Causation Should Shift to the Defendant Under the New Federal Trade Secrets Act, 13 Hastings Bus. L.J. 1, 16–17 (2016).
• 177United States v. Regeneron Pharms., Inc., No. 20-11217, 2023 WL 7016900, at *12 (D. Mass. Oct. 25, 2023).
• 178J.J.C., Res Ipsa Loquitur - Burden of Proof, 5 La. L. Rev. 344, 346 (1943).
• 179United States ex rel. Martin v. Hathaway, 63 F.4th 1043, 1055 (6th Cir. 2023), cert. denied, 144 S. Ct. 224 (2023).
• 180Sanne H. Knudsen, The Long-Term Tort: In Search of a New Causation Framework for Natural Resource Damages, 108 Nw. U. L. Rev. 475, 537 (2014).
• 181Id. at 538 (citing Rutherford v. Owens-Ill., Inc., 941 P.2d 1203, 1219–20 (Cal. 1997)).
• 182Cf. Staples v. United States, 511 U.S. 600, 601 (1994) (“The Government’s interpretation potentially would impose criminal sanctions on a class of persons whose mental state—ignorance of the characteristics of weapons in their possession—makes their actions entirely innocent. Had Congress intended to make outlaws of such citizens, it would have spoken more clearly to that effect.”); Liparota v. United States, 471 U.S. 419, 426 (1985) (“Similarly, in this case, the failure of Congress explicitly and unambiguously to indicate whether mens rea is required does not signal a departure from this background assumption of our criminal law. This construction is particularly appropriate where, as here, to interpret the statute otherwise would be to criminalize a broad range of apparently innocent conduct.”).
• 18342 U.S.C. § 1320a-7b(b)(1).
• 184Josh J. Leopold, Examining Causation Standards in False Claims Act Cases Predicated on Anti-Kickback Statute Violations, Univ. Chi. L. Rev. Online (Jan. 24, 2023), https://lawre‌v‌i‌e‌w‌.‌uchicago.edu/online-archive/examining-causation-standards-false-claims-act-cases-predicated-anti-kickback [perma.cc/K7BD-Y687].
• 185United States v. Regeneron Pharms., Inc., No. 20-11217, 2023 WL 7016900, at *12 (D. Mass. Oct. 25, 2023).
• 186Id.
• 187Id. at *13.
• 188Id.
• 189United States v. Regeneron Pharms., Inc., 128 F.4th 324, 333–34 (1st Cir. 2025).