The False Claims Act is a powerful statutory vehicle for the federal government to deter fraud on its purse, a significant public policy concern. Under the Act, government contractors can be liable for violating material legal requirements of federal programs. In assessing materiality, the courts are asked to evaluate the natural tendency of a violation to influence payment. One question that has been raised in a series of cases in the health product domain is whether government’s payment, despite knowledge of a violation, necessarily means that the violation was immaterial for the purposes of FCA enforcement. The industry is asking the courts to adopt that defense—what this Note terms the “immateriality presumption from agency inaction”—at the pleading stage. To justify the presumption, the defendants argue that the nuanced judgments of the agency vested with the authority and the requisite expertise to regulate—here, the Food and Drug Administration—must prevail over both the private parties who bring actions under the statute’s qui tam provisions, as well as anyone else within the government. Using the Act’s evolution, structure, legislative history, and empirical data, this Note argues against the presumption. First, it shows that the Act’s design strikes a deliberate balance between encouraging private actors and their meaningful oversight by the government. As such, the presumption is not needed to combat unmeritorious private claims. Second, the Note argues that potential overlap between enforcement under the Act and agency oversight is valuable in several ways. The Note’s most significant contribution is in explaining why the immateriality presumption, by tethering fraud enforcement to judgments of the agencies, could be harmful to the agencies them- selves and public interest writ large. In doing that, the Note challenges the claim that the presumption honors the expertise and facilitates the discretion of agencies.