Wayne DeVeydt, a healthcare veteran who most recently worked at Bain Capital, will take up the finance chief job on Sept. 2 as the healthcare behemoth faces an array of operational challenges.

UnitedHealth said on Thursday it will replace its finance chief John Rex with an external hire, Wayne DeVeydt, adding to the management changes at the health insurer that has been struggling to control its medical costs.

Wayne DeVeydt, 55, will take over as UnitedHealth CFO on Sept. 2, the company said, replacing John Rex, who had served in the job since 2016. Rex, 63, will become a strategic adviser to UnitedHealth CEO Stephen Hemsley at that time.