UnitedHealth Group CEO Andrew Witty is stepping down from his post for personal reasons and the health care giant says it’s suspending its full-year forecast due to higher-than-expected medical costs.

Stephen Hemsley ran UnitedHealth Group for more than a decade. It's a different company after four years with Andrew Witty in charge.

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.