The False Claims Act imposes liability on anyone who knowingly submits, or causes to be submitted, a false or fraudulent claim for payment to the federal government, and healthcare is its single largest enforcement arena because Medicare and Medicaid pay out an enormous, continuously flowing volume of claims. Most cases begin as qui tam actions, filed under seal by a relator (often a current or former employee, biller, or physician) on the government's behalf, giving the Department of Justice time to investigate before deciding whether to intervene. The statute's scienter requirement is what separates fraud from an honest billing mistake: liability requires actual knowledge, deliberate ignorance, or reckless disregard of the claim's falsity, not mere negligence in a complex reimbursement system.

Materiality is the doctrine that has reshaped healthcare FCA litigation more than any other in recent years — a false statement or certification is only actionable if it would have actually influenced the government's decision to pay, not merely if it technically violated a regulation buried in a provider agreement. That distinction matters enormously in healthcare, where billing and compliance regulations are dense and providers routinely have some technical noncompliance somewhere in their operations. Cases frequently layer an Anti-Kickback Statute violation underneath the FCA claim, since a claim tainted by an illegal kickback is treated as false per se, and the combination of per-claim penalties, treble damages, and a relator's percentage recovery creates settlement pressure that can dwarf the government's actual measured loss on any individual claim.

The government's intervention decision, made at the end of the sealed investigation period, is the single event that most reshapes case strategy: an intervened case brings DOJ's investigative resources and settlement leverage to bear and usually resolves through negotiated settlement, while a declined case leaves the relator's counsel to litigate alone against a well-resourced healthcare defendant, changing the entire risk calculus for both sides. Because damages are often proven through statistical extrapolation across a large universe of claims rather than claim-by-claim proof, the sampling methodology itself becomes a major point of dispute, and the combination of per-claim penalties with treble damages means even a modest extrapolated base can produce an exposure figure that dwarfs the government's actual measured loss.