Lawyers' Professional Liability

Veteran litigator Matthew K. Flanagan has joined Marshall Dennehey as a Shareholder and Co-Chair of the firm’s Disciplinary Board Representation Practice Group, joining Josh J.T. Byrne in leading the practice. He will divide his time between the firm’s Long Island (Melville) and New York City offices. Previously, he was a Partner at Catalano Gallardo & Petropoulos, LLP in Jericho, NY.  

Flanagan is a highly skilled litigator with over 30 years of trial and appellate experience, primarily defending lawyers against malpractice actions and Judiciary Law 487 claims and grievances. He also represents professionals in accounting, financial services and other industries when professional liability claims are brought against them. He has successfully tried cases in New York City and its surrounding counties, and has secured dozens of victories in attorney liability cases in New York State’s appellate courts.

“We're thrilled to welcome Matt to our professional liability team in New York,” said Craig S. Hudson, Director of Marshall Dennehey’s Professional Liability Department and a member of the firm’s Executive Committee. “When it comes to legal malpractice litigation and representing clients before attorney grievance committees, it would be difficult to find anyone in the entirety of the state with a more distinguished record of success. We are confident that our clients will greatly benefit from the experience and knowledge he brings to the position.” 

Flanagan lectures throughout the state on legal malpractice prevention and defense, ethics and professional responsibility. His articles relating to attorney ethics have been cited in the authoritative codification of the laws of New York, as well as New York’s leading treatise on the Rules of Professional Conduct.

Among his numerous professional memberships, he is President of the Theodore Roosevelt American Inn of Court, and is a member of the New York State Bar Association's Law Practice Management and Insurance Committees. He is a longtime member of the Nassau County Bar Association, and served as Chair of the Association’s Ethics Committee from 2019 to 2022. He is also a longtime member of the American Bar Association.

Flanagan is recognized as a New York Metro Super Lawyer and is rated AV-Preeminent® by Martindale-Hubbell, the highest peer-review ranking for an attorney’s professional and ethical competence. A graduate of St. John’s University School of Law and Fordham University, he is admitted to practice before the courts of the State of New York, the United States District Courts for the Southern and Eastern Districts of New York, and the United States Court of Appeals for the Second Circuit.