Jon Lahn is a partner in the Firm’s Government, Regulatory and Internal Investigations and Litigation practice groups. Whether representing clients who are under investigation by criminal, civil or regulatory authorities, or advising companies on internal investigations and compliance issues, Jon’s practice focuses on helping companies address the complex issues that arise in highly-regulated industries. With a pragmatic approach that is tailored to the specific needs of each client, Jon helps clients efficiently resolve potential legal exposure and mitigate risk.

In the health care and life sciences industries, Jon has represented branded and generic pharmaceutical manufacturers, device manufacturers, diagnostic companies, and health care providers in dozens of federal and state investigations, including investigations relating to potential violations of the Anti-Kickback Statute, False Claims Act, and related state laws, as well in civil litigation arising out of those investigations. He also advises companies on internal investigations relating to health care compliance issues and counsels them on how best to mitigate compliance risk in the future. In addition, Jon advises companies contemplating transactions in the health care space regarding compliance risks and legal exposure.

Jon also represents U.S. and international issuers, professional service firms, and individuals in investigations and enforcement actions by the Securities & Exchange Commission and the Public Company Accounting Oversight Board. He has particular experience in SEC and PCAOB matters relating to audit quality and compliance with the Commission’s auditor independence regulations.

Jon also maintains an active pro bono practice focused on civil rights issues and is a member of Kirkland’s Firmwide Pro Bono Management Committee.


Thought Leadership


Contributor, Antitrust Law Developments (Seventh), Chapter 8: Criminal Enforcement (2012)

Contributor, American Bar Association Antitrust Sentencing Guidelines Handbook (2012)

Author/Presenter, “Is the Seventh Circuit the New Third Circuit?,” Kirkland Antitrust and Competition Institute (2011)

“Writing as Remedy: The Possibilities of Court-Generated Narrative in ‘Personal Status Litigation’,” 34 Vermont Law Review 121 (2009)

“The Demise of the Law-Finding Jury and the Birth of American Legal Science,” 57 Cleveland State Law Review 553 (2009)

Note, “The Uses of History in the Supreme Court’s Takings Clause Jurisprudence,” 81 Chicago-Kent Law Review 1233 (2006)

Memberships & Affiliations

Member of the Illinois State Bar Association


Admissions & Qualifications

  • 2007Illinois


  • United States District Court for the Northern District of Illinois
  • United States Court of Appeals for the Seventh Circuit
  • United States District Court for the Western District of New York


  • Polish


  • Chicago-Kent College of Law at Illinois Institute of TechnologyJ.D.with High Honors2007

    Order of the Coif

    Chicago-Kent Law Review, Executive Notes & Comments Editor, 2006–2007

  • Northwestern UniversityB.A., English2003