Mark H. M. Sosnowsky



Mark Sosnowsky provides high-octane defense to clients stalled by complex civil disputes and allegations of criminal wrongdoing, driving home their cases in mediation, arbitration, federal and state court litigation, and administrative proceedings. Leveraging his background as a clerk for the Third Circuit, Mark is also an effective appellate advocate, with experience steering cases before federal and state courts of appeal. Through rigorous courtroom defense and regulatory counsel, Mark gives companies license to focus on their operations, not the opposition.

Corporate Representation

Mark defends companies and individuals against allegations of federal criminal violations and civil fraud offenses and represents companies conducting their own internal inquiries and investigations. He handles matters involving federal and state False Claims Act (FCA) allegations, environmental offenses, securities fraud, mail and wire fraud, government contracting fraud and regulatory violations and has experience in multiagency and cross-border investigations.

Mark routinely represents corporations and other entities in high-stakes litigation and complex commercial disputes. His litigation experience extends to a variety of matters, including:

  • Defending companies in the healthcare, defense, and housing industries against government and relator-driven False Claims Act allegations.
  • Challenging multiemployer pension plan withdrawal liability assessments under ERISA and the Multiemployer Pension Plan Amendments Act.
  • Representing officer, directors, and controlling shareholders in intra-corporate disputes.
  • Navigating complex real estate disputes on behalf of owners, developers and lenders.
  • Representing companies and individuals in theft of intellectual property and trademark infringement disputes.

Health Care Fraud and Compliance

Mark advocates for health care clients in compliance investigations and civil litigation, particularly FCA/qui tam litigation. He defends hospitals and other providers accused of violating the Anti-Kickback Statute (AKS) and Stark Law, upcoding Evaluation and Management (E&M) services, overbilling Medicare for patients who did not satisfy inpatient criteria and other alleged fraud. In addition, he represents clients in state and federal investigations and internal compliance audits and assists clients in developing effective compliance programs.

Previous Experience

Mark previously clerked for The Honorable Franklin Van Antwerpen of the U.S. Court of Appeals for the Third Circuit.


Bar Admissions

District of Columbia
New Jersey

Court Admissions

U.S. Supreme Court
U.S. Court of Appeals for the District of Columbia Circuit
U.S. Court of Appeals for the Federal Circuit
U.S. District Court for the District of Columbia
U.S. District Court for the Eastern District of Pennsylvania
U.S. District Court for the Eastern District of Virginia
U.S. District Court for the District of New Jersey


U.S. Court of Appeals for the Third Circuit, 2004-2005


Boston University School of Law
J.D. cum laude, Boston University Law Review (2004)

Pennsylvania State University
B.A. (1997)

Insights & Events

The Faegre Drinker Biddle & Reath LLP website uses cookies to make your browsing experience as useful as possible. In order to have the full site experience, keep cookies enabled on your web browser. By browsing our site with cookies enabled, you are agreeing to their use. Review Faegre Drinker Biddle & Reath LLP's cookies information for more details.