More than two dozen Democrats in Congress, including U.S. Rep. Ilhan Omar of Minnesota, are asking a federal judge to let a whistleblower lawsuit move forward that alleges profiteering through the unlawful use of medical coding data by Eden Prairie-based UnitedHealth Group.

The lawmakers argue in their May 15 court filing that a jury should be allowed to pass judgment on company practices the U.S. Department of Justice alleges have wrongfully inflated corporate earnings from the Medicare Advantage program at taxpayer expense. A special master who examined the evidence recommended earlier this year that the long-running whistleblower lawsuit should be terminated via summary judgment.

"It's way past time to rein in the wasteful and harmful practices committed by corporate health insurers in [Medicare Advantage] starting with UnitedHealthcare," Omar said in a statement to the Minnesota Star Tribune. "I joined the amicus brief to finally hold them accountable for stealing money from taxpayers and abusing the Medicare Advantage program."

The lawsuit, which the Justice Department joined as a plaintiff in 2017, argues UnitedHealth Group engaged in one-sided reviews of medical charts to find evidence supporting higher payments for the company, but failed to use the same techniques to fix billing codes that would tend to lower the company's fees.

In a statement, UnitedHealth Group pointed to a March report from a court-appointed special master that concluded the Justice Department's extensive efforts thus far had not recorded evidence of overpayments or wrongdoing by the company.

Medicare Advantage is a privatized version of the federal health insurance program for seniors, where beneficiaries receive government-funded benefits via private insurance companies that manage the network of doctors and hospitals members can visit. UnitedHealth Group operates UnitedHealthcare, which runs the nation's largest Medicare Advantage plan.

UnitedHealth notes that the federal Centers for Medicare and Medicaid Services provides extensive oversight of the program.

"As evidenced by the recently released risk adjustment validation audits, our results continue to demonstrate the accuracy of our coding and the integrity of our practices," the company said in a statement to the Star Tribune. "It is unfortunate to see politically motivated attempts by longtime opponents of Medicare Advantage trying to extend a case that has been thoroughly reviewed and found to lack merit."

In her March 3 ruling, Special Master Suzanne Segal found a "complete failure" of evidence from the Justice Department to support key aspects of its lawsuit, and wrote of the company's practices: "There simply was no fraud."

"The money at issue is alleged overpayments the government claims United received as a result of submitting allegedly invalid diagnosis codes in connection with the Medicare Advantage program," Segal wrote. "The fatal flaw in the government's case is the complete absence of evidence of such overpayments, an essential element of the government's claim."

The Justice Department said in April that Segal's conclusions were "fundamentally flawed," arguing a federal court in California should let the litigation proceed. Judge Fernando Olguin will consider the special master's report at a hearing scheduled for June 12 in the U.S. District Court for the Central District of California.

It will be a pivotal moment in a case that dates back to 2011, when Benjamin Poehling, a former director of finance for UnitedHealth Group in Minnesota, filed his original whistleblower complaint.

In Medicare Advantage, the government pays health insurers a per-member, per-month, up-front payment to cover the cost of health care needs for beneficiaries, including higher fees for sicker populations. Health plans can increase their pay by submitting "risk adjustment" data on patients likely to need more care.

The Justice Department argues that medical coding professionals hired by UnitedHealth reviewed charts to find data that would support higher payments to the company, but systematically ignored information that would have lowered fees from the government.

"United cannot have it both ways," the lawmakers wrote in their amicus brief filed with the court. "It cannot argue, on one hand, that chart review is error prone and may be too complex to consistently identify unsupported codes, while simultaneously maintaining that its additional codes (and associated payments) are justifiable."

The filing referenced the considerable scrutiny UnitedHealth has faced in recent years for its business practices in Medicare Advantage, including a 2024 report from the Office of the Inspector General at the U.S. Health and Human Services Department. The watchdog agency found UnitedHealth was the biggest user among insurers of questionable diagnosis data to boost Medicare Advantage payments.

Earlier this month, the Wall Street Journal reported the Justice Department had launched a criminal fraud investigation of Medicare billing practices at UnitedHealth.

"United is the world's most egregious upcoder and chief among the private [Medicare Advantage] insurers employing fraudulent and abusive tactics to retain funds that rightfully belong either in the Medicare Trust Funds or in the hands of the American taxpayers," the lawmakers wrote in their filing.

Last week, Judge Olguin ordered UnitedHealth Group to file its response to the lawmakers' amicus brief by Friday.