Thomas O'Brien

Assistant Attorney General, Office of the Attorney General of Massachusetts

Thomas More O’Brien is an Assistant Attorney General and Chief of the Health Care Division in the Office of the Attorney General of Massachusetts. Attorney General Martha Coakley created the Health Care Division upon taking office in 2007 to place a heightened focus on promoting the interests of consumers as Massachusetts undertook its landmark health reform effort. O’Brien has successfully led the Health Care Division through significant policy work and litigation against numerous health plans, health care providers, and pharmaceutical companies returning tens of millions of dollars to Massachusetts. During the past two years, he led the Health Care Division’s groundbreaking examination of health care cost trends and cost drivers. 

O’Brien started his career in public service in the Executive Office for Administration and Finance, where he helped launch the Office of Purchased Services that reformed the Commonwealth’s system for purchasing health and social services from private vendors, including development and implementation of the Commonwealth’s first relational database of vendor cost report information.  

O’Brien received a J.D. from Suffolk University Law School, an M.P.A. from the University of Massachusetts at Amherst, and a B.S. (mathematics) and a B.A. (English literature) from the College of Santa Fe.