Bell’s tenure as chief executive concludes an 11-year run at the helm, preceded by eight years as the hospital's chief operating officer. She first informed the Board of Trustees of her retirement plans in 2024, triggering a structured search process that brought Mitchell into the organization in April 2025. Since joining, he has integrated into the hospital’s operational and strategic framework, working alongside Bell to prepare for the upcoming shift in governance.

Mitchell brings a background that blends clinical training with high-level corporate strategy. A former partner at McKinsey & Company, he previously served as executive vice president at Boston Children’s Hospital and president of Franciscan Children’s. His experience includes overseeing major capital campaigns and campus modernization efforts. As he prepares to lead the 170-year-old institution, Mitchell is expected to focus on the hospital's ongoing regional expansion and its mission to address complex pediatric health challenges. Greg Davis, chairman of the Board of Trustees, credited Bell with strengthening the hospital's global standing while expressing full confidence in Mitchell’s ability to guide the next phase of the organization’s growth.