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Hon. Diane M. Welsh (Ret.)
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Hon. Diane M. Welsh (Ret.)

General Biography
Practice Areas
Antitrust & Competition
Business Commercial
Civil Rights
Class Action & Mass Tort
Construction Defect
Cybersecurity & Privacy
Education Law
Employment Law
Entertainment & Sports
Environmental Law
Estate Probate Trusts
Federal Law
Governmental & Public Agency
Health Care
Intellectual Property
International & Cross-Border
Life Sciences
Maritime Admiralty
Personal Injury/Torts
Product Liability
Professional Liability
Real Property
Honors, Memberships, and Professional Activities
Background and Education

“She’s very creative, smart and savvy about both the law and human nature.”
          - Chambers USA 

“Judge Welsh was excellent in her command of the issues and her willingness to lead the parties. She was efficient in methods of sharing proposals to resolution. She was a great and skilled neutral.”
          - Leading Litigator

“She is a superb settler of cases. She is tenacious, persistent, and imaginative.”
          - Almanac of the Federal Judiciary

Hon. Diane M. Welsh (Ret.)
 is highly respected for her ability to successfully resolve disputes with sensitivity, patience, and persistence. Over the past 27 years, as a JAMS neutral and a United States Magistrate Judge, she has successfully resolved over 5000 matters, covering virtually every type of complex dispute. Specifically, Judge Welsh has extraordinary skill in resolving high-stakes multi-party commercial disputes, employment matters, catastrophic personal injury cases, class actions, mass torts and multi-district litigations (MDL’s). She was recognized as a 2016-2018 “ADR Champion” by the National Law Journal, and in the 2022 and 2023 edition of Chambers USA for Mediators (USA – Nationwide) and for Chambers USA 2023 Litigation: Mediators (Pennsylvania).

Class Actions, Mass Torts, and MDLs
Judge Welsh is nationally recognized for her work as a neutral and Special Master in complex class actions, mass torts, and multi-district litigations (MDLs).  Select examples of this work include:

  • Appointed Settlement Mediator for the highly publicized multidistrict litigation involving hundreds of consumer lawsuits against Philips for its recall of millions of C-PAP breathing devices.   Judge Welsh’s brokered settlement resulted in Philips agreeing to pay $479M to resolve the economic claims and to reimburse consumers for device purchases, rentals, and other out-of-pocket costs plus an additional $95M in attorneys’ fees.
  • Appointed Special Master of the Amtrak Train Derailment Settlement Program related to the 2015 derailment of a Philadelphia passenger train. The program will distribute $265m in claims arising from the incident.
  • Mediated settlement of class action lawsuit against T-Mobile stemming from its 2021 data breach involving personal information of 76.6M U.S. residents, T-Mobile’s fifth breach in four-years. Allegations included T-Mobile failed to properly protect personal information, had inadequate data security, and violated certain state consumer statutes and other laws. T-Mobile denied these allegations and did not admit liability in the proposed settlement requiring T-Mobile to pay $500M on customers’ claims and bolster cybersecurity practices.
  • Mediated case involving large financial services corporation over its handling of data security breaches and alleged failure to wipe personal identifiable information data (PII) before decommissioning and reselling computer equipment on which the data was stored for 15M+ customers and former customers. While continuing discovery in the case, both parties agreed to mediate the claims and engaged Welsh who, over a five-month period, helped the parties achieve a $60M settlement providing both monetary and equitable relief for plaintiffs, including fraud insurance coverage and out-of-pocket cost reimbursement associated with remedying the breach.
  • Class action involving claims under NY and NJ consumer protection laws. The certified classes comprise NY and NJ consumers that updated their phones during an upgrade. Class asserted that the upgrade significantly diminished phone performance. Although denying wrongdoing, defendant is entering into settlement to avoid burdensome and costly litigation. Total compensation is capped at $20M.
  • Successfully mediated case involving claims of antitrust conspiracy where plaintiffs allege that three trading firms and their warehouse affiliates (“defendants”) conspired to hoard aluminum and engage in other anticompetitive behavior to restrict supply, inflate all-in aluminum prices and regional premiums, and provided inefficient, low-quality load-out and other services. Judge Welsh successfully resolved the dispute with a $37M settlement.
  • Successful mediation in the multi-district litigation, Wright Medical Technology, Inc. Conserve Hip Implant Products Liability Litigation. 
  • Mediated a global settlement of the state and federal products liability proceedings brought against Stryker Orthopedics --  In re: HOC Rejuvenate and ABG II Hip Implant Products Liability Litigation, a federal multi-district litigation venued in the United States District Court for the District of Minnesota, and In re: HOC Rejuvenate Hip Stem and ABG II Modular Hip Stem Litigation Case, a New Jersey state multi-county litigation venued in Bergen County, New Jersey.  Prior to mediating the global settlement, between 2013 and June 2014, Judge Welsh mediated more than 20 bellwether cases in the New Jersey multi-county litigation.  Ninety-five percent of registered eligible patients have enrolled in the settlement program under the master settlement agreement.  She currently serves as Claims Administrator overseeing the implementation of the settlement and continues to mediate opt-out cases.  

ADR Experience and Qualifications

  • Conducted nearly 1,800 settlement conferences as a U.S. Magistrate Judge in virtually every area of civil litigation, including complex commercial, insurance, class action, mass torts, employment, serious personal injury, product liability, professional liability malpractice, antitrust, securities, government, civil rights, environmental, education, aviation, intellectual property, maritime, product liability, real estate, construction, consumer, sports, and entertainment
  • Served on the Alternative Dispute Resolution committee for the United States District Court for the Eastern District of Pennsylvania for 10 years, drafting local federal court rules for court-annexed mediation program
  • Frequent speaker at Continuing Legal Education programs on settlement negotiation, mediation, and the ADR Act

Representative Matters

  • Antitrust & Competition
      • Mediated claims of conspiracy by Internet bond trader against major brokers and dealers
      • Mediated claims of price fixing of blood reagent products
      • Mediated claims of price fixing in the pharmaceutical industry
  • Aviation
      • Mediated claims by passengers of Swissair flight 111
      • Mediated accidents involving private planes
      • Mediated a matter involving a plane that crashed into a house resulting in injuries to the resident
      • Mediated an insurance coverage dispute arising from a helicopter crash 
  • Business Commercial
      • Successfully mediated hundreds of business disputes involving breach of contract, corporate, franchise, licensing, partnership, shareholder's rights, stock purchase agreements, and breach of warranty claims
      • Mediated a dispute between a northeastern energy company and a contractor alleging breach of contract, indemnification, fraud and conspiracy to commit fraud regarding federally mandated testing of employees 
      • Mediated multiple cases against universities for failure to partially reimburse tuition after moving to virtual learning during COVID-19 
      • Mediated a warranty dispute between a supplier and a manufacturer of hot water heaters 
      • Meditated a dispute against two defendants for allegedly targeting immigrants to sell life insurance policies and fraudulently promising large profits 
      • Mediated a breach of contract dispute between a third-party health care provider and an insurance company for failure to refer policy holders 
  • Civil Rights
      • Mediated wrongful death cases involving a cluster of suicides inside a county jail and another within a correctional facility
      • Mediated a high profile case on behalf of severely abused child against private foster care placement agency and government agencies
      • Mediated a claim against school district on behalf of special education student raped by their students in classroom supervised by a substitute teacher
      • Mediated cases involving alleged hazing, harassment and sexual misconduct on a University sports team
      • Mediated multiple Title IX and Tort cases including claims of sexual abuse involving faculty, clergy and students in colleges, universities, primary and secondary schools, boarding schools and foster care
  • Class Action & Mass Tort
    • In addition to the class action matters listed above, has mediated a wide variety of matters including:
      • Several class actions  involving bank overdraft fees 
      • Deceptive labeling claim against a national retail chain regarding reef-safe sunscreen 
      • Claims involving the misrepresentation of sheet thread count by a national department store 
      • Claims of false advertising regarding an electrolyte supplement company 
      • Alleged violation of the Fair and Accurate Credit Transactions Act (FACTA) 
      • RICO allegations brought by home buyers alleging specific violations
      • Claims involving federal and state consumer protection statutes against Builder, Mortgage Brokers, Appraiser, and Mortgage Lender
      • ERISA/Securities Fraud class action by former employees of a national insurance company and a multi-national chemical company
      • Multiple wage and hour class actions
      • Unfair, deceptive and bad faith billing for supplying electricity to residential customers
      • Claims involving a defective component part on a water supply line
      • Breach of contract and breach of the covenant of good faith and fair dealing related to pricing practices on electric energy bills
      • Violations of the Telephone Consumer Protection Act (TCPA)
      • Consumer class action in connection with the repossession and resale of financed vehicles
      • Cases involving the Fair Credit Reporting Act and the Fair Debt Collection Practices Act
  • Construction Defect
      • Mediated claim by general contractor against regional transportation authority totaling more than $20 million dollars of cost overruns due to post contract federal requirements regarding lead paint abatement
      • Mediated a construction defect matter involving alleged negligence ion a reconstruction project 
  • Cybersecurity & Privacy
      • Successfully mediated a number of cyber breach disputes involving various industries including credit reporting, banking, health care, traditional media social media, gas stations, software, benefit administration, 
      • Mediated a cyber breach dispute in which a company contracted to perform contact tracing during COVID-19 disclosed private health information (PHI) and personal identifying information (PII) on unsecured servers
      • Mediated a class action involving alleged privacy violations by a stationary bicycle company’s digital platform
  • Employment Law
      • Successfully mediated thousands of claims of discrimination (age, disability, gender, national origin); hostile work environment; retaliation; wage & hour; FLSA, ADA; FMLA, state statues, whistleblower/False Claims Act; harassment; denial of long-term disability insurance; employment contract; trade secrets; denial of employment due to criminal background checks issued under the FCRA
  • Entertainment & Sports
      • Mediated copyright and royalty claims by songwriters and artists against record producers and distributors; 
      • Mediated contract and breach of fiduciary duty claim by heavyweight boxing champion against a promoter 
      • Mediated employment discrimination and contract claims by various employees against professional sports teams; 
      • Mediated personal injury claims brought by professional football players against NFL teams
  • Environmental Law
      • Mediated claims by the USA and state against more than twenty defendants in major environmental Superfund case
      • Mediated a California Environmental Quality Act (CEQA) dispute involving water permits; issues involved included whistle-blower protection and allegations of retaliation, harassment and severe emotional distress
  • Estate Probate Trusts
      • Mediated a breach of fiduciary duty by placing trust assets in underperforming proprietary funds
  • Health Care
      • Mediated a dispute between and insurance company and a health care provider regarding treatment and allegedly fraudulent billing practices
      • Mediated a coverage dispute involving a hospital’s losses as a result of COVID-19
      • Mediated a payor/provider dispute alleging under payment for services in bad faith
  • Insurance
      • Mediated claims of bad faith, coverage, property damage, reinsurance, and subrogation
      • Mediated coverage disputes over damages sustained by commercial properties in the wake of Superstorm Sandy
      • Mediated an indemnity claim between a rideshare service and a vendor company that failed to screen drivers resulting in an assault 
      • Mediated a coverage dispute regarding property damage to vacant buildings
      • Mediated a coverage dispute involving the cancellation of a medical conference due to COVID-19
  • International & Cross-Border
      • Mediated a dispute between two Mexican agribusinesses who claimed breach of warranty against the manufacturers of an anti-viral vaccine
  • Maritime Admiralty
      • Mediated multiple Jones Act cases; disputes between ship owners and insurers over cause of loss-mechanical failure or human error
  • Personal Injury/Torts
      • Successfully mediated cases involving complex catastrophic personal injury and wrongful death, workplace injuries, nursing home negligence, product liability (including multiple defective medical device claims, pharmaceuticals, as well as food labeling claims), motor vehicle, toxic torts, municipal and governmental tort liability, Dram shop/liquor liability, and premises liability
  • Professional Liability
      • Mediated numerous cases involving legal malpractice, fee disputes, medical malpractice, chiropractic malpractice, accounting, executives, directors, and officers
  • Real Property
      • Mediated numerous cases involving issues such as partnership, joint venture, and contract disputes in major real estate development projects; disputes over real estate commissions; violation of franchise agreements
  • Securities
      • Mediated numerous individual and class actions involving claims of fraud
      • Mediated cases alleging breach of fiduciary duty by financial advisors and brokers
      • Mediated anticompetitive acts and practices as a part of an overall scheme to improperly maintain and extend monopoly power in the making for a pharmaceutical drug, causing the payment of overcharges
  • Sexual Abuse
      • Successfully mediated settlements in numerous cases involving highly sensitive claims of sexual and physical abuse concerning adult and minor children and group/class action plaintiffs. Disputes included matters involving: alleged abuse at a prestigious boarding school; sex abuse leading to suicide of a college student; allegations of sexually charged hazing and misconduct in connection with university-sponsored sports teams; numerous cases involving sexual abuse claims against Archdioceses, Catholic and other religious schools, and nonsectarian private and public schools; disputes involving victims of incest and church officials; and matters regarding sex trafficking allegations against a major hotel chain

Honors, Memberships, and Professional Activities

  • Included on "National Mediators" list, Chambers USA America's Leading Lawyers for Business, 2022 and 2023
  • Included on Chambers USA America’s Leading Lawyers for Litigation: Mediators (Pennsylvania), 2023
  • Completed Virtual ADR training conducted by the JAMS Institute, the training arm of JAMS
  • Listed as a "Recognized Practitioner," Chambers USA, 2019
  • Recognized as an “ADR Champion”, National Law Journal, 2016-2018
  • Voted “BEST ADR INDIVIDUAL” by the readers of ALM’s Legal Intelligencer, Best of 2007-2016
  • Recognized as Mediation "Lawyer of the Year", Philadelphia, Best Lawyers in America, 2014
  • Recognized as a Best Lawyer, Alternative Dispute Resolution Category, Best Lawyers in America, 2007-2024
  • Recognized as a Pennsylvania Super Lawyer, Alternative Dispute Resolution Category, Law & Politics Magazine, 2008-2009
  • Voted "Best Individual Mediator", National Law Journal, "Best Of" Survey, 2012
  • Member, Federal Magistrate Judges Association; Third Circuit Director, 1999-2004
  • Member, The Forum of Executive Women
  • Member, American Inns of Court; President, Temple American Inn of Court, 2002-2003
  • Member, National Association of Woman Judges, Federal Bar Association, Montgomery Bar Association, Philadelphia Bar Association,
  • Bucks County Bar Association, Pennsylvania Bar Association, and other professional organizations
  • Member of Third Circuit and U.S. District Court for the Eastern District of Pennsylvania court committees, including Federal-State
  • Judicial Council, Committee on Bankruptcy and Magistrate Judges, Alternative Dispute Resolution Committee, Court Interpreters
  • Committee, Bench Bar Public Relations and Educational Programs Committee, and Congressional Delegation Committee

Background and Education

  • U.S. Magistrate Judge, U.S. District Court for the Eastern District of PA, 1994-2005
  • Private Law Practice, 1984-1994
  • Deputy District Attorney, Bucks County District Attorney’s Office, 1981-1984
  • Legal Counsel, Pennsylvania Senate Judiciary Committee, 1980-1981
  • J.D., Villanova University School of Law, 1979
  • B.A., Political Science, Magna Cum Laude, La Salle University, 1976


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