Mark Hamer Exits DOJ's Antitrust Division After Landmark Year

Mark Hamer, a deputy assistant attorney general at the U.S. Justice Department's Antitrust Division, announced his departure after a significant year of civil antitrust enforcement. He cited 2025 as a pivotal year with a heavy docket of cases in various industries. Hamer returns to private practice at Baker McKenzie.

Mark Hamer, who served as the deputy assistant attorney general at the U.S. Justice Department's Antitrust Division, announced his resignation on Monday. His decision comes after a significant year in public service, marked by extensive antitrust litigation.

Hamer, in a LinkedIn post, highlighted 2025 as a noteworthy year for civil antitrust enforcement, with an unprecedented volume of cases handled by the division. The cases spanned several key industries including technology, healthcare, and finance.

Returning to private practice, Hamer rejoins Baker McKenzie as the former global chair of the firm's antitrust and competition practice. His tenure at the Justice Department began in March of the previous year, where he played a crucial role in overseeing litigation and enforcement activities.