News & Events

Marshall Dennehey is pleased to announce that 10 attorneys have been elected shareholders of the firm effective Jan. 1, 2025. Additionally, two attorneys have been promoted from associate to special counsel. These new shareholders and special counsel represent the firm's four core departments – Casualty, Professional Liability, Health Care and Workers' Compensation – and come from eight of the firm's 19 offices. 

Marshall Dennehey has been named a "2025 Best Law Firm" in multiple practice areas, both nationally and across numerous regions of the country, by Best Lawyers®. Nationally, the firm ranked in the practice areas of Mass Tort Litigation/Class Action – Defendants, Commercial Litigation; Insurance Law; and Litigation- Construction.   

Marshall Dennehey is proud to be a signator to Project LITIGATE – Lawyers Initiative To Improve next Gen Attorneys’ Trial Experience – an initiative from the Pennsylvania Supreme Court that has been ratified by the Pennsylvania Conference of Civil Trial Judges.

Stuart H. Sostmann, shareholder and co-chair of Marshall Dennehey’s Construction Injury Litigation Practice Group, has been named Managing Attorney of the the firm’s Pittsburgh office. He inherits the position from Scott G. Dunlop who served in the role for almost 30 years and will retire at the end of the year. Sostmann has served as Assistant Managing Attorney of the Pittsburgh office since 2023.

Marshall Dennehey is proud to highlight the firm’s 109 attorneys who have been recognized in the 2025 editions of The Best Lawyers in America® and the Best Lawyers: Ones to Watch® in America. Less than 6% of all practicing lawyers in the U.S. were selected by their peers for this recognition.

Additionally, six of the firm’s attorneys received the Best Lawyers® 2025 “Lawyer of the Year” awards in their respective practice areas and demographic regions. 

Teresa O. Sirianni, shareholder in the Professional Liability Department in the Pittsburgh office of Marshall Dennehey, has been elected to membership of the Academy of Trial Lawyers of Allegheny County.