Larson serves as a director on the board of Unum Group, chairing Unum's Regulatory Compliance Committee, and as a director of Boston Private Financial Holdings Inc. Larson served on the Executive Committee for the Boston 2024 Partnership, the non-profit organization that attempted to bring the 2024 Summer Olympic and Paralympic Games to Boston, and co-chaired the group’s College and University Engagement Committee. She also previously served as a director on the boards of KeySpan Energy and RSA Security before the companies were acquired by National Grid and EMC, respectively, as well as on the board of Blue Cross Blue Shield of MA. Larson presently holds the post of president of the Massachusetts Conference for Women and is the past president of the Massachusetts’ Women's Forum. In addition, she is a board or advisory council member of several prominent professional, charitable and civic organizations including Roger Williams University School of Law, the Massachusetts Clean Energy Center, the Massachusetts High Technology Council, University of Massachusetts Center for Collaborative Leadership and Rosie's Place. She is a member of the Bar in Massachusetts and Virginia.