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Sean P. Mahoney Partner

Philadelphia, PA | Direct 215.864.6342Fax 215.789.7577
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Sean Mahoney is a trusted advisor to insurers and commercial clients who is respected for his knowledge, responsiveness, creativity and understanding of his clients’ business. He has extensive and successful trial and litigation experience in state and federal courts, as well as in numerous private arbitrations involving complex commercial insurance coverage, financial lines insurance, life insurance, reinsurance, business torts and commercial contract disputes. He has achieved significant victories as lead counsel representing insurers in jury and federal bench trials, in numerous private arbitrations, and as an appellate advocate.

Sean's insurance practice spans a broad range of complex insurance coverage matters.  He frequently serves as lead counsel representing commercial insurers in litigation involving directors and officer’s liability insurance, fiduciary liability insurance, commercial general liability insurance, employment practices liability insurance, professional malpractice liability insurance policies, errors and omissions policies, and various types of excess liability insurance.  He routinely evaluates coverage and advises third-party primary and excess liability insurers in coverage litigation frequently involving disputes between multiple insurers and coverage towers. Sean also often advises life insurers with respect to life insurance policies and litigates disputes over life insurance claims. Sean’s diverse insurance coverage practice has also included litigating commercial property insurance coverage issues and transnational reinsurance coverage disputes.

Sean has also successfully litigated numerous commercial contract disputes both within and without the insurance industry. Within the insurance industry, commercial insurers have frequently called upon him to oversee and litigate disputes involving the collection of premiums, managing general agents, retail agents, insurance producers, and third-party claims administrators. Outside of the insurance industry, Sean has also counseled clients and handled litigation over sale-of-goods and service contracts, surety agreements, and the collection and enforcement of judgments.

Since Sean is a problem-solver, clients often seek his advice and counseling with respect to insurance coverage and commercial matters outside of the litigation context. He has frequently negotiated favorable resolutions for insurers and other clients involved in disputes with third parties that have avoided costly and protracted litigation.

Sean regularly publishes articles and delivers presentations to clients and general audiences about important insurance coverage issues. He has been published in The Legal Intelligencer and he has taught several Masters classes at White and Williams’ annual Coverage College® event on a variety of topics, such as the potential effects of climate change on the business and coverage aspects of the insurance industry, drafting effective reservation-of-rights letters, best practices for handling claims, the right to independent counsel and how cutting-edge new technologies can potentially change how insurers manage insurance claims and the risks they choose to underwrite. Sean has also spoken at CLE events on the potential effects of the COVID-19 pandemic upon employment practices liability insurance and the potential coverage issues raised, the insurability of punitive damages in various jurisdictions, and conflicts-of-law issues in the liability insurance coverage context.

While in law school, Sean served as an Editor of the Villanova Environmental Law Journal and as a Board Member of the Public Interest Fellowship Program at Villanova Law School. Upon graduation, Sean served as judicial law clerk in the United States Court of Appeals for the Third Circuit before entering private practice in 2004.

Representative Matters

  • Obtained summary judgment in favor of defendant insurer in the District of Delaware absolving it of any duty to defend and/or indemnify with respect to an underlying ERISA liability class action against a large defense contractor in a “related claims” case and successfully argued on appeal to the U.S. Court of Appeals for the Third Circuit to persuade the Court of Appeals to affirm the District Court’s award of summary judgment.  See Northrop Grumman Corp. v. AXIS Reins. Co., et al., No. 1:17-CV-01738, 2018 U.S. Dist. LEXIS 183804 (D. Del. Oct. 26, 2018), aff’d, No. 19-1949, 2020 U.S. App. LEXIS 12903 (3d Cir. Apr. 22, 2020)
  • Obtained summary judgment in June 2019 in favor of large commercial general liability insurer in Commerce Program of the Philadelphia Court of Common Pleas determining that another insurer was required to reimburse our client insurer for six-figure defense costs expended in underlying serious construction accident case pursuant to Additional Insured provisions.
  • Successfully negotiated pre-suit settlement in 2019 of high profile wrongful death claim under multi-million dollar excess liability insurance policy in Pennsylvania
  • Obtained arbitration award in December 2018 in favor of excess and surplus lines liability insurer from three-member arbitration panel concluding that insurer had no duty to defend or indemnify insured under the $1 million primary general liability policy with respect to underlying wrongful death action in Pennsylvania
  • Obtained summary judgment in March 2016 in favor of commercial liability insurer in Pennsylvania federal court concluding that lower, $100,000 policy limit for reimbursement of defense costs only, without any indemnity coverage, applied instead of higher, $1 million indemnity limit with unlimited defense cost reimbursement and further obtained judgment against insured for reimbursement of defense costs
  • Obtained a six-figure award from a three-member private arbitration panel for a global commercial insurer in a dispute against an insurance producer over failure to remit commercial liability insurance premiums
  • Successfully tried action in Kentucky for unpaid commercial liability insurance premiums to a six-figure jury verdict representing plaintiff insurer and nearly quadrupled damages award after successful appeal
  • Successfully defended a commercial liability insurer in a federal bench trial against claims that a premium refund was due as a result of alleged mid-term cancellation of liability insurance and achieved ruling of no liability for insurer
  • Successfully obtained summary judgment and interpleader relief dismissing counterclaims against national life insurer client in multiple state and federal court cases in Pennsylvania and New Jersey

Recognition & Involvement

Sean has been selected in a survey of his peers as a Pennsylvania “Rising Star” in Insurance Coverage or Business Litigation by Super Lawyers nearly every eligible year since 2007.   

Sean strongly believes in the value of volunteering time to give back to the local community. In that regard, he routinely provides pro bono legal work in conjunction with the Senior Law Center in Philadelphia. Sean also leads volunteer committees at his local church, has served as a Commissioner and team coach of the local Boys Youth Basketball league in Swarthmore, Pennsylvania for the past several years and often volunteers his time to coach several local youth sports teams and to support local charitable events.



Bar and Court Admissions


New Jersey

U.S. District Court for the District of New Jersey

U.S. District Court for the Eastern District of Pennsylvania

U.S. District Court for the Middle District of Pennsylvania

U.S. District Court for the Western District of Pennsylvania

U.S. Court of Appeals for the Third Circuit


Villanova University School of Law, JD, 2002

University of Notre Dame, BA, 1999



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