The Trump Administration has filed a complaint and intervened in a suit against UnitedHealth Group accusing the health insurance giant of Medicare Advantage overcharges involving its UHC of California plan.

The suit was filed originally in 2009 by former Senior Care Action Health Plan employee James Swoden in California, and is titled United States ex rel. Swoben v. Secure Horizons, et al.

This comes on the heels of the U.S. Department of Justice intervention in a related case, United State ex rel. Poehling v. UnitedHealth Group Inc. The government is slated to file a complaint in that case by May 16.

That case, too, claimed the health insurer overcharged Medicare.

Both cases were filed under the False Claims Act, which lets private parties sue on behalf of the United States for false claims on government funds, and to share in any monies recovered.

At issue are inflated payments from the government because of inaccurate health status data for patients enrolled in the plan, according to the StarTribune.

“Defendants knowingly presented or caused to be presented a false or fraudulent Risk Adjustment Attestation to the Government in order to receive and retain risk adjustment payments from the Medicare Program” charged the suit filed May 1 in Los Angeles by the DOJ.

The lawsuit alleges that “since 2005, UnitedHealth knew that many diagnosis codes that it submitted to the Medicare Program for risk adjustment were not supported and validated by the medical records of its enrolled beneficiaries,” the government said in its complaint.

The action is a shot across the bow to insurers, according to the DOJ. "This action sends a warning that our office will continue to scrutinize and hold accountable Medicare Advantage insurers to safeguard the integrity of the Medicare program," Acting U.S. Attorney Sandra Brown in Los Angeles said, according to the St. Louis Post-Dispatch.

But UnitedHealth has fought back against this depiction of their actions, claiming that it followed the rules appropriately. "We reject these claims and will contest them vigorously," company spokesman Matthew Burns protested, according to the paper, stressing that his company was clear about the process it followed filing claims and “how we interpreted the government's murky policies."

UnitedHealth is the largest Medicare Advantage group in the U.S.

The suit claims that the insurer paid for chart reviews by HealthCare Partners to see if it could boost risk-adjusted payments for patients being cared for by that group. At issue is a claim that the insurer “allegedly ignored information from these chart reviews about invalid diagnoses, and thus avoided repaying Medicare monies to which it was not entitled,” according to Pasadena News Now.

These reviews "identified information leading to increased government payments ... while systematically ignoring information that would have led to decreased payments," the lawsuit stated. "By failing to 'look both ways,' UnitedHealth improperly generated and reported skewed data artificially inflating beneficiaries' risk scores, avoided negative payment adjustments and retained payments to which it was not entitled," according to the StarTribune.

“The intervention of the United States in this matter illustrates our commitment to ensure the integrity of the Medicare Part C program,” said Acting Assistant Attorney General Chad A. Readler of the Justice Department’s Civil Division.