UnitedHealth’s Old CEO Stages Comeback With Legacy Under Siege

Stephen Hemsley never fully dropped the reins when he stepped down as UnitedHealth Group Inc.’s chief executive officer eight years ago. With the health giant in crisis, he’s taking back his old job – and confronting one of the toughest turnaround tasks any executive has ever faced.

Widely credited with building UnitedHealth into the conglomerate it is today, Hemsley, 72, was reluctant to end his tenure as CEO in 2017, according to people familiar with the matter who asked for anonymity to describe internal company discussions. The board had asked him to step aside at age 65, but he ...