UnitedHealth Group said Chief Financial Officer John Rex will leave the post in September and become a strategic adviser, ending a nine-year tenure in the role. The insurer appointed Wayne DeVeydt, a Bain Capital operating partner and former executive chair of Surgery Partners, as his successor. DeVeydt is also stepping down from Centene’s board to avoid a conflict of interest between the rival health insurers. The management overhaul follows a year in which UnitedHealth’s share price has tumbled more than 50% amid elevated medical costs, an 89.4% medical loss ratio reported last quarter and federal probes into its Medicare Advantage billing practices. Executive chairman Stephen Hemsley retook the helm in May after the abrupt departure of Chief Executive Officer Andrew Witty, pledging further changes to restore performance and governance. UnitedHealth shares gained as much as 4% on Tuesday, their steepest advance since July 1. The move was helped by a Wolfe Research note indicating the thresholds for Medicare Advantage plans to earn quality-bonus payments could ease in 2026, potentially boosting insurer margins. Traders also cited unverified speculation that Warren Buffett’s Berkshire Hathaway is building a position in the company, though no filings have confirmed a stake.