A court-appointed special master has found that U.S. authorities do not have evidence to support their billion-dollar fraud case accusing UnitedHealth Group of keeping overpayments from the government for patients on its Medicare insurance plans.

The civil fraud case against UnitedHealth Group, the nation’s largest Medicare Advantage insurer, was filed in 2011.

The case began with a whistleblower who said UnitedHealth bilked billions of dollars through the Medicare Advantage program.

The Justice Department lacks evidence to support claims the company withheld Medicare Advantage funds, a legal expert overseeing the case said.

UnitedHealth Group notched a major court win in a legal challenge over its Medicare Advantage (MA) billing practices that is stretching into its second decade. | UnitedHealth Group notched a major court win in a legal challenge over its Medicare Advantage billing practices that is stretching into its second decade.