UnitedHealth Sinks as Report of Criminal Probe Adds to Woes (2)

UnitedHealth Group Inc. plummeted as much as 18% following a report that the insurer was under criminal investigation for possible Medicare fraud, adding to an already tumultuous week.

The Justice Department has had a probe into the company’s Medicare Advantage business since at least last summer, the Wall Street Journal reported, citing unidentified people familiar with the matter.

UnitedHealth said in a statement late Wednesday that the Department of Justice hadn’t notified the company about the reported investigation.

“We stand by the integrity of our Medicare Advantage program,” it added.

UnitedHealth shares dropped every day for the last eight ...