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 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.

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

UnitedHealth Group Inc UNH announced Tuesday morning that its CEO, Andrew Witty, will resign for personal reasons.. Stephen Hemsley, who previously held the CEO title from 2006 to 2017, will succeed him. Hemsley will also remain chairman of UnitedHealth's board of directors, and Witty will become senior adviser to the CEO.

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 shares rebounded modestly Wednesday following yesterday's crash, with analysts from UBS, Oppenheimer, and Morgan Stanley leaving their ratings unchanged after the health insurer pulled its outlook and announced its CEO had stepped down.