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, 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.

Stephen Hemsley hasn’ t been CEO at UnitedHealth Group in nearly a decade yet he’ s never really left. Since that day, the company’ s stock has fallen from $610 a share to $308 on Tuesday, an unprecedented decline for the company that culminated in this week’ s CEO transition.

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.

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 revealed on Tuesday that its CEO Andrew Witty is stepping down due to personal reasons. Witty would remain a senior advisor as he is replaced by former CEO and longtime company leader Stephen Hemsley, who has been board chair since 2017.

British boss of US healthcare giant UnitedHealth quits for ‘personal reasons’ - The move comes five months after one of the company’s top executives was killed after being shot as he walked to an investor conference in New York.

Stephen Weiss, who frequently appears on CNBC, noted on the network yesterday that he was holding onto his position in UnitedHealth Group Incorporated (UNH) after UNH’s CEO, Andrew Witty, resigned, citing “personal reasons.