UnitedHealth under investigation over alleged Medicare fraud, report says - UnitedHealth said it was not notified about the “supposed criminal investigation reported.”

Stephen Hemsley ran UnitedHealth Group for more than a decade. It's a different company after four years with Andrew Witty in charge.

UnitedHealth faces valuation reset amid CEO change, regulatory probes, and cost overruns. Click here for a full analysis of UNH stock.

Former CEO and current chairman Stephen Hemsley is stepping back into the top job following the abrupt resignation of Andrew Witty, UnitedHealth said.

UnitedHealth's stock has plunged nearly 40% year-to-date as the company has battled a series of crises. Can the healthcare giant turn it around? Seeking Alpha analysts weigh in.

As CEO for more than a decade, Stephen Hemsley built up UnitedHealth Group, now a $400 billion healthcare behemoth. With his return to the top job, the company will learn whether his playbook still works.

UnitedHealth Group, the largest health insurer in the country, is turning back the clock in a moment of crisis. On Tuesday, the company announced that chairman Stephen Hemsley is returning as CEO, stepping back into the role he left in 2017.