UnitedHealth Group will change leaders next month, promoting long-time executive David Wichmann to replace CEO Stephen Hemsley, who has led the nation's largest health insurer since 2006.

The 54-year-old Wichmann currently is currently the company president and has overseen its biggest business, which focuses on health benefits, since 2014. Wichmann joined the company in 1998, a year after the 65-year-old Hemsley arrived.

The Minnetonka, Minnesota, company said Wednesday that Wichmann will take over Sept. 1, and Hemsley will become executive chairman of the board. Current Chairman Richard Burke will become lead independent director.

In its most recent quarter, UnitedHealth Group Inc. earned $2.28 billion and raised its forecast for 2017.

The insurer's shares jumped in early-morning trading.