UnitedHealth (UNH) stock was down Friday on a report from The Wall Street Journal that the health insurance company faces a Department of

UnitedHealth Group (UNH) shares declined more than 11% in premarket trading after The Wall Street Journal reported that the Justice Department has launched a civil fraud investigation into the company’s Medicare billing practices.

UnitedHealth Group shares tumbled early Friday on a report that the U.S. Department of Justice has started an investigation into the health care giant’s Medicare billing practices

The health insurance giant has called a new report from WSJ "misinformation," but investors may not be so sure. Shares were down about 9% early Friday.

UnitedHealth Group called The Wall Street Journal's report "misinformation" and said it was unaware of reported investigaiton.

And the fact that the government, especially a populist government, looks into this, has to follow, especially this case specifically, Matt, because The Wall Street Journal for some time has been running kind of this investigative series about UnitedHealth and these practices.