Few statutes have recovered more money for the federal government than the False Claims Act (FCA). Since the modern amendments of 1986, the law has returned tens of billions of dollars to the U.S. Treasury — most of it through cases brought not by the government, but by private citizens. That engine, known as the qui tam mechanism, is now under the most serious constitutional scrutiny it has faced in its modern history. A federal court in Florida has declared it unconstitutional, and the U.S. Court of Appeals for the Eleventh Circuit is poised to decide whether that ruling stands. The outcome could reshape fraud enforcement nationwide.
A Quick Refresher on Qui Tam
The False Claims Act imposes liability on those who knowingly submit false claims for payment to the federal government — think Medicare and Medicaid billing, defense procurement, pandemic relief funds, and government grants. What makes the statute unusual is that it deputizes private individuals, called relators, to sue on the government's behalf. A relator files suit under seal, the Department of Justice investigates, and the government decides whether to intervene. If the case succeeds, the relator can collect a share of the recovery — typically 15 to 30 percent.
This structure has made the FCA the federal government's most powerful civil fraud tool. The vast majority of recoveries originate with whistleblowers who see misconduct from the inside. Critically, even when the government declines to intervene, a relator may continue to litigate the case alone, in the name of the United States.
The Zafirov Decision
On September 30, 2024, Judge Kathryn Kimball Mizelle of the U.S. District Court for the Middle District of Florida did something no federal court had done before: she held the FCA's qui tam provisions unconstitutional. The case, United States ex rel. Zafirov v. Florida Medical Associates, LLC, involved a relator who alleged that her former employer misrepresented patient diagnosis codes to obtain inflated Medicare reimbursements. The government declined to intervene, so the relator pressed forward on her own.
Rather than reaching the merits of the fraud allegations, the court dismissed the case on constitutional grounds. Judge Mizelle reasoned that a qui tam relator is an officer of the United States under Article II's Appointments Clause — and because relators are self-appointed rather than nominated and confirmed (or properly appointed by a department head), the statute violates the Constitution's structural requirements for who may wield executive power.
The Constitutional Theory
The court's analysis turned on two findings. First, relators exercise significant authority under federal law: they can initiate litigation on behalf of the United States and, in declined cases, control that litigation with few guardrails — deciding what claims to pursue, what theories to advance, and whether to settle. Second, relators occupy a continuing position established by law, because the FCA effectively creates a standing "office of the relator." Taken together, the court concluded, a relator looks enough like an executive officer that the Appointments Clause should apply — and the qui tam structure cannot satisfy it.
The opinion drew heavily on a 2023 dissent by Justice Clarence Thomas, who had invited exactly this challenge, suggesting that the historical pedigree of qui tam actions may not be enough to square them with modern separation-of-powers doctrine. Notably, Judge Mizelle concluded that the long historical practice of treating relators as something less than "officers" did not cure the Article II problem she identified.
The Appeal: Oral Argument Before the Eleventh Circuit
Both the Department of Justice and the relator appealed, and on December 12, 2025, a panel of the Eleventh Circuit heard oral argument in Zafirov (No. 24-13581). The panel — Judges Robert J. Luck and Elizabeth L. Branch, joined by Senior District Judge Federico A. Moreno sitting by designation — pressed both sides hard, signaling that the court is taking the constitutional question seriously rather than treating the district court's outlier ruling as an easy reversal.
Observers across the defense and qui tam bar described the argument as closely contested. The judges probed the historical record of qui tam actions dating to the founding era, the degree of government control retained over declined cases, and whether a relator's temporary, case-specific role really resembles a continuing federal office. No matter how the panel rules, the losing side is widely expected to seek further review.
Why This Matters Beyond Florida
Several federal circuits have already rejected similar constitutional challenges to the FCA. If the Eleventh Circuit affirms Judge Mizelle's decision, it would create a direct split among the circuits — precisely the kind of disagreement the U.S. Supreme Court exists to resolve. With at least three sitting Justices having signaled interest in the issue, a circuit split would dramatically raise the odds of Supreme Court review.
The stakes are enormous. If qui tam ultimately falls, the federal government would lose its most productive fraud-detection channel, and countless pending whistleblower suits — particularly declined cases proceeding without DOJ — could be dismissed. If the provisions are upheld, as most courts have held to date, the status quo continues but with sharpened doctrinal clarity. Either way, the uncertainty itself is already affecting litigation strategy on both sides of the "v."
Practical Takeaways
For companies that bill federal programs — health care providers, government contractors, and grant recipients chief among them — the constitutional cloud over qui tam does not change the underlying compliance obligation. The FCA's substantive prohibitions remain fully enforceable, and the government can always pursue fraud directly. The takeaways are more strategic than they are a green light:
- Preserve the argument. Defendants in FCA matters — especially declined cases within the Eleventh Circuit — should consider raising the constitutional challenge to avoid waiver while the issue is live.
- Watch the venue. The strength of the argument now depends heavily on jurisdiction. What may gain traction in the Eleventh Circuit could be foreclosed elsewhere.
- Do not relax compliance. Even a defense-favorable ruling would not legalize fraud. Robust billing controls, internal reporting channels, and prompt investigation of red flags remain the best protection.
- Plan for volatility. Settlement value, litigation timelines, and risk assessments should account for the possibility that the rules governing relator standing may shift on appeal.
The Bottom Line
Zafirov has transformed a long-simmering academic debate into a live appellate question with national consequences. A ruling from the Eleventh Circuit is expected to follow the December 2025 argument, and a petition to the Supreme Court may not be far behind. For now, the qui tam mechanism remains in force everywhere — but no one defending or bringing an FCA case can afford to ignore the constitutional question that Florida's federal courts have placed squarely on the national agenda.