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

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.

UnitedHealth Group said CEO Andrew Witty is stepping down for “personal reasons” and suspended its 2025 forecast, sending shares of the healthcare giant tumbling nearly 10%. Witty will act as a senior advisor to his successor,