UnitedHealth Group Chairman Stephen Hemsley is returning to helm the health care conglomerate once again. He will replace Andrew Witty effective immediately.

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

UnitedHealth Group is giving its returning CEO Stephen Hemsley $60 million in equity, in addition to a $1 million annual salary. Why it matters: Hemsley stepped down from his role as CEO in 2017 after more than a decade,

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.

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

UnitedHealth has faced several headwinds in the recent past, ranging from a cyberattack, which had greater than initially realized impacts, to the tragic killing of its CEO, which caused the company to suffer harsh public backlash over the company's and industry practices.

Even UnitedHealth will struggle to overcome parasitic medical costs that Warren Buffett once called a tapeworm eating away at U.S. economic competitiveness. The $300 billion healthcare conglomerate reinstalled Chairman Stephen Hemsley as CEO and yanked its financial guidance.

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.