Mr. Merenstein has a comprehensive litigation practice, ranging from first and second-chairing jury trials to handling state and federal court appeals to serving as court-appointed special master in a number of complex federal cases. 

He has extensive experience mediating difficult disputes and has been responsible for hundreds of appeals covering a wide variety of subject matters.  Mr. Merenstein was an adjunct professor of appellate advocacy at Drexel University School of Law from 2007 through 2015. 

Before attending law school, Mr. Merenstein worked for almost a decade in labor relations.  He also has completed two intensive, week-long mediation courses at Harvard Law School’s Program on Negotiation, including an advanced workshop on mediating complex disputes.


Mr. Merenstein’s trial practice has included roles as lead counsel and co-lead counsel in civil and criminal matters at both jury and bench trials; second-chair responsibility in many additional jury and bench trials; and briefing and arguing numerous pre-trial and post-trial dispositive motions.

Mr. Merenstein’s appellate practice has included the preparation and editing of hundreds of briefs, supervision of other lawyers’ brief drafting, and presentation of dozens of oral arguments in a wide variety of appeals in federal and state court.  His appellate representations have run the full gamut of civil and criminal matters, as well as regulatory, procedural, and jurisdictional issues.  He has handled a number of high-profile criminal appeals involving complex legal issues.  He also has joined trial teams as appellate counsel, handling all motion briefing and argument in the trial court, developing the legal arguments to complement the trial team’s presentation of the facts, and taking responsibility for such matters as issue preservation and proposed jury instructions.

Mr. Merenstein has extensive experience mediating discovery and other protracted disputes, primarily in his frequent role as a court-appointed special master. He has helped resolve hundreds of discovery disputes in high-stakes and complex cases involving anti-trust, RICO, securities fraud, toxic tort, personal injury, and other claims. He also has been called upon to mediate contentious attorneys’ fee disputes and to oversee non-jury trials.

Mr. Merenstein’s mediation and related matters include:

  • Serving as court-appointed Special Master in numerous complex federal cases, including mass tort, false marketing, and anti-trust claims;
  • Presiding over eight-day evidentiary hearing and preparing detailed findings of fact, conclusions of law, and proposed order regarding ultimate outcome in False Claims Act case;
  • Preparing extensive report and recommendation to federal court regarding motion to dismiss
    based on complicated issues of federal-court jurisdiction;
  • Mediating and facilitating resolution of hundreds of discovery disputes regarding attorney-client privilege, document production, electronically-stored information, fact and expert depositions, medical examinations, third-party discovery, and other contested issues;
  • Successfully mediating nine separate objections to proposed distribution of $143 million common benefit fee among 17 law firms;
  • Resolving disputes between seven state attorneys general and common benefit fee committee over states’ contributions to common benefit fund.
  • Helping to craft voluntary lien resolution program adopted by approximately 45 health care plans, numerous plaintiffs, and defendant for handling third-party lien claims; and
  • Serving as Judge Pro Tem in Philadelphia Court of Common Pleas, presiding over mandatory settlement conferences in major jury cases.


  • American Academy of Appellate Lawyers, Fellow
  • American Law Institute, member
  • Academy of Court-Appointed Neutrals, Fellow
  • Lawyers Advisory Committee of the Judicial Council of the Third Circuit, member (appointed by Chief Judge, 2017-2019)
  • Philadelphia Bar Association; Appellate Courts Committee, co-chair (2016-2017); Federal Courts Committee, chair (2015), vice chair (2014); Commission on Judicial Selection and Retention, investigator (2006-present)
  • Bar Association for the Third Federal Circuit, founding member
  • American Bar Association, member


  • Or Hadash Reconstructionist Synagogue Board of Directors, 2002-2005; 2012-2020
  • Upper Dublin School District Budget and Finance Task Force, 2010-2011
  • Upper Dublin School District Gifted Education Review Committee, 2007-2008
  • Upper Dublin Township Historic Preservation Committee, 2002-2005
  • Upper Dublin School District Educational Advisory Committee, 2000-2005


  • Completed Advanced Mediation Workshop: Mediating Complex Disputes course at Harvard Law School’s Program on Negotiation, 2019
  • Best Lawyers‘ Philadelphia Appellate Practice “Lawyer of the Year,” 2017 and 2021
  • Listed in The Best Lawyers in America for Appellate Law, 2008-2023 and Criminal Defense: White Collar, 2021-2023
  • Rated AV® Preeminent by Martindale-Hubbell®
  • Recognized among ‘Pennsylvania Super Lawyers’ in the area of Appellate Law, 2009-2022
  • Completed Mediating Disputes course at Harvard Law School’s Program on Negotiation, 2014
  • Two time recipient of the Burton Award for Legal Achievement, 2007 and 2009
  • Recipient, Earl G. Harrison Pro Bono Award, 2008
  • Honors from HIAS & Council, a public-interest immigration advocacy organization, in recognition of outstanding pro bono work on an asylum case, 2005
  • Recognized among ‘Pennsylvania Rising Stars’ by Super Lawyers in the area of appellate law, 2005-2007 
  • Online columnist for appellate issues for The Legal Intelligencer Blog, 2008-2012
  • Winner of the University of Pennsylvania Law School’s prestigious Keedy Cup moot court competition, 1998
  • Graduation awards from the University of Pennsylvania Law School for best constitutional law paper, best civil procedure paper, and most significant contribution to the Law Review, 1998  
  • University of Pennsylvania Law Review Executive Editor, 1997-98; Associate Editor, 1996-97