Mark Hamer Departs U.S. Justice Department's Antitrust Division

Mark Hamer, the deputy assistant attorney general at the U.S. Justice Department's Antitrust Division, announced his resignation on February 9, 2026, after nearly a year in his role. Hamer stated that he had committed to a one-year term of public service upon accepting the position. He plans to return to private practice at Baker McKenzie, where he previously served as the global chair of the law firm's antitrust and competition practice. Hamer's tenure was marked by significant civil antitrust enforcement, which he described as the "high-water mark" for such actions in 2025, with the largest docket of civil antitrust litigation in the department's history.

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During his time at the Justice Department, Hamer oversaw various enforcement cases and investigations that targeted competition concerns across multiple industries, including technology, healthcare, entertainment, agriculture, real estate, and financial services. His departure raises questions about the future direction of the Antitrust Division, especially as it continues to address high-profile cases in a politically charged environment.

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In his LinkedIn post announcing his departure, Hamer reflected on the achievements of the Antitrust Division, emphasizing the importance of civil antitrust enforcement. He stated, "The year 2025 was the high-water mark for civil antitrust enforcement, with the largest docket of civil antitrust litigation matters in DOJ’s history." His return to Baker McKenzie is seen as a move back to the private sector, where he can leverage his experience gained during his time in government.

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While Hamer's departure is primarily viewed as a personal career decision, it occurs amid broader scrutiny of the Justice Department's antitrust policies. Critics have raised concerns about the effectiveness of antitrust enforcement under the Trump administration, questioning whether the momentum achieved during Hamer's tenure will be sustained. The future leadership of the Antitrust Division will be crucial in determining how aggressively the department continues to pursue antitrust cases.

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As Hamer transitions back to private practice, the Justice Department will need to appoint a successor to fill his role. This appointment will be pivotal in shaping the agency's approach to antitrust enforcement moving forward, particularly as the political landscape evolves and new challenges arise in the marketplace.

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• “The year 2025 was the high-water mark for civil antitrust enforcement, with the largest docket of civil antitrust litigation matters in DOJ’s history,” — Mark Hamer, Deputy Assistant Attorney General

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• “Our enforcement cases and investigations targeted high-profile competition concerns in technology, healthcare, entertainment, agriculture, real estate and financial services industries,” — Mark Hamer, Deputy Assistant Attorney General

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