UnitedHealth Group (UNH) is under scrutiny by the US Department of Justice for allegedly encouraging doctors to record diagnoses that result in extra payments to the insurer's "Medicare Advantage" plans, the Wall Street Journal reported Friday, citing people familiar with the matter.

The Justice Department has started a civil fraud investigation into UnitedHealth Group's billing practices in recent months, the report said.

The news outlet reported it had previously published articles showing that patients examined by the company's employed doctors experienced significant increases in money-making diagnoses after enrolling in the "Medicare Advantage" plans, in which insurers receive payments from the federal government to oversee enrollees' Medicare benefits.

The department and UnitedHealth Group declined requests for comment from the Journal. They also did not immediately respond to MT Newswires' requests for comment.

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