May 13 (UPI) -- UnitedHealth Group announced Tuesday CEO Andrew Witty will step down, citing "personal reasons." Witty will leave the role of CEO and be replaced by Stephen J. Hemsley, effective immediately.

Former UnitedHealth Group chief executive officer Stephen Hemsley to replace Andrew Witty. Here's what we know.

Andrew Witty has resigned as chief executive of US health conglomerate UnitedHealth Group, as the company pulled its financial forecasts for 2025, adding to a sense of crisis after a turbulent period.

UnitedHealth Group CEO Stephen Hemsley, returning to run the healthcare giant after Andrew Witty resigned, said he has the right strategy in place “for the era ahead.”

"We are grateful for Andrew's stewardship of UnitedHealth Group, especially during some of the most challenging times any company has ever faced," Hemsley said. "The Board and I have greatly valued his leadership and compassion as chief executive and as a director and wish him and his family the best.