Catherine D. Stewart

CATHERINE STEWART focuses on representing companies in both internal investigations and enforcement actions brought by federal and state authorities, including the Department of Justice, United States Attorney’s offices, the Department of Health and Human Services Office of Inspector General, the Drug Enforcement Agency, and state Attorney General Offices. Catherine also has experience in compliance program assessments, including providing oversight of the implementation of a Corporate Integrity Agreement for the duration of the Corporate Integrity Agreement (CIA).

Catherine works with a wide variety of clients including pharmaceutical and medical device manufacturers, pharmacies, premarket life science companies, electronic health software manufacturers, e-commerce platforms, and private equity firms focused on healthcare acquisitions. 

Best Lawyers: Ones to Watch® in America has recognized Catherine Stewart for Commercial Litigation and Health Care Law (2026).

Catherine graduated summa cum laude and valedictorian from John Marshall Law School in 2015. Her awards and recognition include first place in the Herzog Appellate Advocacy Competition; the Arba N. Waterman Scholarship, awarded to the student with the highest rank after the second year of law school; and the John N. Jewett Scholarship, awarded to the student with the highest class rank after the first year. Catherine was also a lead articles editor at the John Marshall Law Review. Prior to attending law school, Catherine earned her Masters Degree from Boston University and taught middle school and high school in New Hampshire.

During law school, Catherine externed for The Honorable Ann Claire Williams on the Seventh Circuit Court of Appeals.

Representative enforcement matters handled by Catherine include:

• Representation of a healthcare provider in a DOJ False Claims Act investigation alleging violations of the Anti-Kickback Statute, Beneficiary Inducement Statute, and coding and billing issues. 
• An elite private university in an antitrust class action in the Northern District of Illinois involving alleged price fixing of financial aid awards.
• Representation of an e-commerce platform in a DOJ Controlled Substances Act investigation alleging violations of the Controlled Substance Act’s civil provisions.
• Representation of an online pharmacy in responding to a Drug Enforcement Agency Order to Show Cause.
• Representation of a life science company in responding to a state AG subpoena raising allegations of medical necessity.
• Representation of a global pharmaceutical company in a DOJ criminal investigation involving allegations off-label promotion and risk minimization. 
• Representation of a global medical device manufacturer in an FCPA investigation related to the company’s arrangements with certain physicians in Israel.
• Represented a pharmacy in investigating concerns about diversion and DEA compliance.
• Represented a pre-market life science company in investigating concerns about pre-approval promotion and retaliation.
• Represented a private equity sponsor and the board of healthcare company against creditor derivative claims of fraud and breach of fiduciary duty.