Mark W. Tanner
Firm
10 Best Lawyers awards
Awarded Practice Areas
Biography
Mark W. Tanner primarily represents victims of medical negligence and insurance bad faith, and also has substantial experience in cases involving disability insurance claims, civil rights claims, and class action litigation. An accomplished Philadelphia Personal Injury lawyer with a wide ranging practice, Mark has handled cases throughout the region and across the country, and has been appointed as a liaison counsel in mass tort litigation at both the state and federal court level. He has secured a $22.4 million verdict for the victim of a negligently executed spine surgery, one of the largest medical malpractice verdicts in Pennsylvania. Mark also secured a $7.9 million verdict, believed to be the largest jury verdict in Pennsylvania against an insurance company in a case alleging bad faith.
Mark has been recognized for seven consecutive years as one of the Top 10 Super Lawyers in Pennsylvania by Thomson Reuters. He is the former president of The Philadelphia Trial Lawyers Association (2007-2008) and the 2005 recipient of its President’s Award. In addition, Mark has been named by The National Trial Lawyers as a Top 100 Trial Attorney in the Civil Plaintiff category and in 2016 was appointed as a hearing committee member serving the disciplinary board of the Supreme Court of Pennsylvania. In recognition of his success at trial, Mark was also one of the youngest attorneys ever invited to become a fellow of the prestigious International Academy of Trial Lawyers (membership limited to 500 lawyers).
In additional to maintaining a robust practice, Mark is a passionate pro bono activist, representing underprivileged and neglected children as a child advocate for the non-profit Support Center for Child Advocates, where he has also served on the board of directors. As a frequent lecturer, Mark has participated in more than 50 continuing legal education programs, and has taught trial advocacy, among other subjects, to law students and graduate LL.M. students at local area law schools. He has lectured throughout the United States and, by invitation, to barristers in London.
When not in court, Mark enjoys traveling, hunting, fishing, and scuba diving, and he constantly struggles with his golf game.
Mark earned a B.A. in English Literature from the College of the Holy Cross, and his J.D. cum laude from Temple University Beasley School of Law. He is licensed to practice in Pennsylvania, the U.S. District Court for the Eastern District of Pennsylvania, the U.S. District Court for the Middle District of Pennsylvania, the U.S. Court of Appeals for the Third Circuit, and the Supreme Court of the United States.
Firm
10 Best Lawyers awards
Overview
- Temple University, J.D., graduated 1990
- Pennsylvania, Pennsylvania, 1990
- United States, Admitted pro hac vice in other states
- American Board of Trial Advocates (ABOTA) - Member, Associate, 2006
- Commission on Judicial Selection and Retention - Investigator
- Disciplinary Board of the Supreme Court of Pennsylvania - Hearing Committee Member , 2016
- Medical Legal Committee - Member
- National Board of Trial Advocacy - Certified Civil Trial Specialist
- Pennsylvania Trial Lawyers Association - Member, Board of Governors, 2009 – Present
- Philadelphia Bar Association - Member, Board of Governors, 2003 – 2006
- Philadelphia Trial Lawyers Association - Member, President, 2007, Board of Directors, 1997 – Present
- State Civil Rules Committe - Member
- U.S. District Court for the Middle District of Pennsylvania, 2009
- U.S. Court of Appeals for the Third Circuit, 2005
- Supreme Court of the United States, 2006
- U.S. District Court for the Eastern District of Pennsylvania, 1991
- Pennsylvania, Pennsylvania, 1990
- United States, Admitted pro hac vice in other states
- American Board of Trial Advocates (ABOTA) - Member, Associate, 2006
- Commission on Judicial Selection and Retention - Investigator
- Disciplinary Board of the Supreme Court of Pennsylvania - Hearing Committee Member , 2016
- Medical Legal Committee - Member
- National Board of Trial Advocacy - Certified Civil Trial Specialist
- Pennsylvania Trial Lawyers Association - Member, Board of Governors, 2009 – Present
- Philadelphia Bar Association - Member, Board of Governors, 2003 – 2006
- Philadelphia Trial Lawyers Association - Member, President, 2007, Board of Directors, 1997 – Present
- State Civil Rules Committe - Member
- Temple University, J.D., graduated 1990
- U.S. District Court for the Middle District of Pennsylvania, 2009
- U.S. Court of Appeals for the Third Circuit, 2005
- Supreme Court of the United States, 2006
- U.S. District Court for the Eastern District of Pennsylvania, 1991
Client Testimonials
Awards & Focus

- Mass Tort Litigation / Class Actions - Plaintiffs, Philadelphia (2025)
- Mass Tort Litigation / Class Actions - Plaintiffs, Philadelphia (2023)
- Mass Tort Litigation / Class Actions - Plaintiffs, Philadelphia (2018)
- Mass Tort Litigation / Class Actions - Plaintiffs
- Medical Malpractice Law - Plaintiffs
- Personal Injury Litigation - Plaintiffs
- Top 10 Super Lawyer in Pennsylvania, 2007 – 2017
- Best Lawyers in America 2013- 2016
- Eddie Ohlbaum Distinguished Advocate for Children Award - Support Center for Child Advocates, 2016
- Fellow - International Academy of Trial Lawyers , 2006
- President’s Award - Philadelphia Trial Lawyers Association, 2005
- Fellow - American Bar Foundation
News & Media
Additional Information
Case History
- $22.4 Million Verdict for Botched Spine Surgery
The constant pain from his botched spine surgery — and two subsequent surgeries required to correct the errors –has left him unable to sit for long periods, his lawyer Mark Tanner of Feldman Shepherd explained.
The jury sat in deliberations for only three hours before returning a $22.4 million verdict, awarding $17.6 million to Mr. Calli and $4.8 million to Mr. Calli’s wife, Sandra, for loss of consortium.
- $11 Million Settlement for Victim of Head-On Collision
Subsequent to the settlement, Tanner and Mann assisted the children in convincing the Wayne County District Attorney to press charges against O’Halloran, as he had never been charged in connection with the accident, and Tanner argued the failure to charge O’Halloran stemmed from the fact that his step father was an officer with the Pennsylvania State Police. After Tanner turned over all of the information he had accumulated to the District Attorney, O’Halloran was charged and convicted, and given a prison sentence.
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