A Los Angeles clinical laboratory has agreed to pay $20.5 million to settle allegations that it knowingly held onto federal overpayments for COVID-19 testing claims filed on behalf of patients who actually had private health insurance. Signal Diagnostics LLC provided testing at public sites and client locations during the pandemic, and the settlement resolves claims that it improperly avoided repaying the government even after discovering the problem internally.
According to Justice News, federal prosecutors alleged that between October 1, 2020, and March 25, 2022, Signal Diagnostics repeatedly submitted reimbursement claims to the HRSA Uninsured Program for COVID-19 testing and specimen collection performed on patients who actually held private insurance, per the Department of Justice. The HRSA program was designed to reimburse providers for testing, treatment, and vaccine administration specifically for uninsured patients, not those with existing coverage.
What makes this case notable, according to the same DOJ account, is not just the original billing errors but what the company allegedly did after it found them. The lab's internal audit uncovered the ineligible claims in or around January 2022, yet the company continued calculating overpayments through May 2023 while improperly delaying refunds to HRSA, according to an account from Traders Union. That gap of well over a year between discovery and repayment sits at the center of the government's legal theory.
Why Holding Onto the Money Matters
Under the False Claims Act's so-called reverse false claims provision, 31 U.S.C. § 3729(a)(1)(G), knowingly concealing or improperly avoiding an obligation to repay money owed to the federal government — including retaining identified overpayments — is itself an actionable violation subject to treble damages, according to the Health Law Alliance. That legal theory doesn't require proving the original claims were submitted fraudulently; it targets what happens after a provider learns it was paid in error.
For Medicare overpayments, Section 1128J(d) of the Social Security Act, created under the Affordable Care Act, mandates that providers report and return self-identified overpayments within 60 days of identification, according to the Centers for Medicare & Medicaid Services. Signal Diagnostics' internal audit flagged the ineligible claims in January 2022, and the DOJ alleged that the company improperly delayed repaying the HRSA overpayments.
A Fund That Ran Dry
The timing carries added weight because the HRSA Uninsured Program itself ran out of money. The program permanently stopped accepting testing and treatment reimbursement claims on March 22, 2022, after exhausting its allocated federal funding, according to the Health Resources and Services Administration. That means the fund shut its doors to genuinely uninsured patients just days after Signal Diagnostics' alleged pattern of improper claims was said to have ended, while the company's overpayments reportedly sat unresolved for more than another year afterward.
The investigation and resulting $20.5 million settlement resulted from a coordinated effort by the DOJ Civil Division's Commercial Litigation Branch, Fraud Section, with assistance from the HHS Office of Inspector General. As is standard in civil False Claims Act resolutions, the agreement resolves the allegations without any judicial determination of liability or admission of wrongdoing by Signal Diagnostics.
Part of a Broader Federal Crackdown
The case lands within a wider federal push to claw back pandemic-era relief funds. In May 2026, the DOJ Civil Division established an expedited review policy requiring federal prosecutors to complete initial reviews of benefits fraud whistleblower complaints within 60 to 120 days. The federal government also established the National Fraud Enforcement Division within the DOJ in 2026 to centralize multi-agency resources and data analytics targeting pandemic relief and public benefits fraud, according to Holland & Knight.
Signal Diagnostics is far from the only testing lab to face this kind of reckoning in recent months. An Oakland County lab agreed to pay $6.5 million in a settlement announced in July. Other laboratory settlements include a $9.62 million Indianapolis lab settlement last November, pointing to a sustained pattern of enforcement against diagnostic testing companies that expanded rapidly during the public health emergency.
For Signal Diagnostics, the agreement provides for a $20.5 million settlement, with a remaining balance due under its terms; the underlying allegations remain legally unresolved claims rather than proven facts. The settlement nonetheless stands as the latest signal that federal regulators are treating delayed repayment of pandemic overpayments as seriously as the original improper billing itself.
