David Geronemus, Esq. is one of the most respected and sought after dispute resolution professionals in the United States. His deep-seated experience as a mediator allows him to skillfully manage and resolve complex and seemingly intractable disputes through a powerful combination of legal acumen, tireless persistence, and thorough preparation. 

Mr. Geronemus’s extensive mediation experience includes both two-party cases and multi-party complex mediations covering a wide spectrum of legal issues. The matters he has mediated include complex business and commercial disputes (breach of contract, fiduciary duty, fraud, negligence, corporate dissolutions and governance), class action and mass tort, professional liability (legal and accounting malpractice), intellectual property (copyright, patent, trademark and licensing), software development and new technologies, cybersecurity and privacy, and ERISA disputes. Mr. Geronemus has adeptly mediated insurance coverage disputes under commercial general liability (CGL) (including asbestos and environmental), property, directors and officers (D&O), errors & omissions (E&O), and representations and warranties policies, as well as reinsurance disputes.  He has also conducted  antitrust/unfair competition, bankruptcy, employment and executive compensation, products liability and securities mediations. 

Several leading legal publications have recognized Mr. Geronemus’s uncompromising commitment to fairness, diligence, and common sense in the conduct of his mediations. Chambers and Partners has identified him as one of the most skilled and widely respected mediators in the U.S. between 2016 and 2024 and has bestowed on him its highest (Band 1) ranking. Chambers reviewers have described him as their “go-to mediator for complex disputes,“ “[e]xemplary in every respect,” “spectacular in his grasp of complicated fact patterns,” and as “the gold standard: brilliant and tireless.” Other Chambers reviewers have noted that he “address[es] the merits of the dispute at length in order to sensitize all participants to the risks of not settling,” that “[h]is attention to detail is unmatched,” that he is “tirelessly diligent,” and that he “quickly gets to the heart of the issues and persists until the matter is concluded.”

Other mediation-related accolades garnered by Mr. Geronemus include Best Lawyers’ designation of him as “Lawyer of the Year” for Mediation (New York City) (2022 and 2024). He has also been recognized by Who’s Who Legal in the practice areas of Mediation (2016 and 2019), and Commercial Mediation (2022 – 2024); that same publication also recognized him as a Commercial Mediation WWL Through Leader: USA in 2023. Mr. Geronemus has also been recognized by Who’s Who Legal: Insurance and Reinsurance (2015, 2023 – 2024), as a Best Lawyer, ADR Category in Best Lawyers in America (2008 – 2025) and as a  New York Super Lawyer by Law & Politics since 2007. 

ADR Experience and Qualifications

• Mr. Geronemus has taught negotiation and alternative dispute resolution on an adjunct basis at Yale Law School and Columbia Law School
• Mr. Geronemus has given guest lectures in the Oxford University seminar, Commercial Negotiation and Mediation 
• A graduate of New York University School of Law, Mr. Geronemus also holds an M.B.A. degree from the Columbia University Graduate School of Business and an undergraduate degree from Wesleyan University
• Mr. Geronemus is a former law clerk to U.S. Supreme Court Justice Potter Stewart and Collins J. Seitz, then Chief Judge of the United States Court of Appeals for the Third Circuit

Representative Matters

• Mediated to settlement a complex insurance coverage case arising out of the sale of certain prescription drugs; case involved approximately 18 parties
• Successfully mediated a dispute between two public companies both in Chapter 11 proceedings, involving allegations of securities fraud as well as preference claims
• Facilitated settlement of numerous employment disputes ranging from disputes under executive employment agreements to discrimination claims
• Successfully mediated class actions, including a case alleging improper charges by an HMO to its members
• Successfully mediated numerous environmental insurance coverage cases, including one case that involved over 250 sites, multiple insurers and over seven hundred million dollars in estimated investigation and remediation costs
• Mediated to settlement a number of cases involving disputes arising out of the operations of closely held and family businesses
• Mediated numerous disputes arising out of commercial and financial transactions, including a multimillion dollar dispute arising out of the sale of a portfolio of mortgage servicing rights
• Mediated several disputes involving insurance coverage for asbestos liabilities. These cases have arisen in both bankruptcy and non-bankruptcy settings. One case involved two insureds and over 30 insurers.
• Successfully mediated a dispute alleging breaches of various representations and warranties in connection with the sale of a billion-dollar portfolio of home equity loans
• Mediated a dispute between an HMO and a provider organization
• Mediation of actions by bankruptcy trustees against directors and officers of failed companies
• Successful mediation of a case involving a breach of a contract to build a website

Honors, Memberships, and Professional Activities

• Designated with the highest-level ranking (Band 1) in Mediation, Chambers USA America’s Leading Lawyers for Business, 2016-2024
• Recognized as Best Lawyers' New York City "Lawyer of the Year" for Mediation, 2022, 2024
• Recognized in Who's Who Legal in the practice area of Mediation, 2016-2019,  Commercial Mediation, 2022-2024, and as a Commercial Mediation WWL Thought Leader: USA in 2023
• Recognized as one of the most highly regarded individuals in the United States in Who’s Who Legal in the practice area of Insurance and Reinsurance, 2015, 2023- 2024
• Recognized as a Best Lawyer, ADR Category, Best Lawyers in America, 2008-2025
• Recognized as a New York Super Lawyer by Law & Politics every year since 2007

ADR Profiles

• "David Geronemus," 2018 ADR Champions, The National Law Journal, June, 2018

Background and Education

• Mediator, JAMS, 1994-present
• Partner, Donovan, Leisure, Newton & Irvine, Washington, D.C. and New York, 1990-1994
• Associate and Partner, Rogovin, Huge & Schiller, Washington, D.C., 1984-1989
• Law Clerk, Supreme Court Justice Potter Stewart, 1983-1984
• Law Clerk, Chief Judge Collins Seitz, U.S. Court of Appeals, 3rd Circuit, 1982-1983
• J.D., New York University Law School, 1982 (Senior Articles Editor, N.Y.U. Law Review; N.Y.U. Alumni Association Award; John Norton Pomeroy Prize, the Leonard M. Henkin Prize; Member, Order of the Coif)
• M.B.A., Columbia University Graduate School of Business, 1980 (Roswell C. McCrea Prize, Beta Gamma Sigma Honor Society)
• B.A., Wesleyan, 1975