Mark Hamer Leaves DOJ Antitrust Post

Mark Hamer, who served as the second‑level officer in the U. S. Justice Department’s antitrust office, has stepped down after nearly a year in the position. He announced his departure on LinkedIn and said he had promised to serve for only a year when he accepted the role. Hamer noted that 2025 was a landmark year for civil antitrust enforcement, with the department handling its biggest pile of cases ever. The work covered a wide range of sectors, from technology and healthcare to entertainment, agriculture, real estate and finance.After leaving the government, Hamer will return to private law at Baker McKenzie, where he once led the firm’s global antitrust and competition practice. He began his DOJ tenure in March, joining a team of four deputies who manage the department’s antitrust litigation and investigations. His exit marks a shift in the agency’s leadership as it continues to pursue high‑profile competition cases across multiple industries.