In a novel False Claims Act (FCA) ruling, on September 30, 2024, Judge Kathryn Kimball Mizelle of the District Court for the Middle District of Florida upended decades of FCA jurisprudence in declaring the qui tam provisions of the FCA unconstitutional in U.S. ex rel. Zafirov v. Florida Medical Associates, LLC, 2024 WL 4349242 (M.D. Fla. Sept. 30, 2024). This decision follows Justice Thomas’ dissent in the recent Supreme Court decision, U.S. ex rel. Polansky v. Executive Health Resources, Inc., 599 U.S. 419 (2023), where he posited, “[t]here are substantial arguments that the qui tam device is inconsistent with Article II and that private relators may not represent the interests of the United States in litigation.” While Justice Thomas’ implicit constitutional challenge was not entirely new to FCA practitioners, including it in his Polansky dissent, with Justices Kavanaugh and Barrett in a concurring opinion noting their agreement that the Court should consider the constitutional questions in an appropriate case, swung wide open a door of opportunity for defendants and their counsel to attempt to dismiss FCA qui tam suits on constitutional grounds. Judge Mizelle’s decision in Zafirov is the first of its kind to actually dismiss a qui tam suit on constitutional grounds, and will likely lead to an avalanche of similar motions in nearly every non-intervened lawsuit brought by a relator.