Mark H. Rosenberg


  • Office Contact Info
  • Biography

    Mark H. Rosenberg is an Associate in the Philadelphia office of GRSM and is a member of the Insurance practice group.

    Mark’s practice focuses on advising and representing clients on insurance coverage, class action and bad faith matters. He assists insurers by providing coverage opinions, prosecuting and defending declaratory judgment actions, and defending insurers with regard to extra-contractual claims, including claims for bad faith. He negotiates and litigates disputes involving first- and third-party coverage matters ranging from property damage to complex personal accident and disability claims.

    Mark has devoted his entire career to representing the insurance industry. He represents insurers in numerous jurisdictions throughout the U.S. and in alternative dispute forums, such as arbitrations and mediations.

    Mark also has experience litigating matters involving a variety of other issues, including antitrust, construction defect, aviation liability, personal injury, and bankruptcy matters. He has extensive experience preparing dispositive motions and responses, preparing oppositions to class certification motions, preparing and responding to discovery requests, and taking and defending depositions.

    Mark co-authored Extra-Contractual Litigation Against Insurers (Law Journal Press 2009), a treatise that provides a comprehensive view of numerous issues involved in litigating bad faith actions and other lawsuits seeking extra-contractual damages. He also assisted Lawyers for Civil Justice in preparing comments to the Civil Rules Advisory Committee of the U.S. Judicial Conference regarding proposed revisions to the Federal Rules of Civil Procedure on electronic discovery.


    • Pennsylvania
    • New Jersey


    • State Bar of Pennsylvania
    • Montgomery County Bar Association
    • American Bar Association
  • Practice Areas
  • Representative Experience
    • Seiple v. Progressive N. Ins. Co., 568 F. App’x 183 (3d Cir. June 12, 2014) — Primary role in developing arguments and drafting a successful appellate brief affirming the dismissal of a putative class action regarding the “stacking” of uninsured/underinsured motorist benefits. The Third Circuit affirmed the trial court’s holding that under Pennsylvania law, the issuance of an amended declarations page confirming the addition of a vehicle under a policy’s after-acquired-vehicle clause did not trigger an insurer’s duty to obtain a waiver of “stacked” UM/UIM coverage.
    • Seiple v. Progressive N. Ins. Co., 954 F. Supp.2d 352 (E.D. Pa. 2013)— Primary role in developing arguments and drafting a successful motion to dismiss in the above-described case.
    • Jones v. Nationwide Prop. and Cas. Ins. Co., 613 Pa. 219, 32 A.3d 1261 (Pa. 2011) — Primary role in developing arguments and drafting a successful appellate brief in a putative class action. The Pennsylvania Supreme Court held that for automobile collision coverage, an insurer did not violate the law by reimbursing a policyholder’s deductible on a pro rata basis after obtaining a subrogation recovery.
    • Cumberland Mut. Fire Ins. Co. v. Express Products, Inc., Civ. Act. 08-2909, 2011 WL 4402275 (E.D. Pa. Sep. 22, 2011) — Major role in developing arguments and drafting a successful motion for summary judgment. The United States District Court for the Eastern District of Pennsylvania confirmed that a liability insurer did not have the duty to indemnify a policyholder for the $8 million settlement of a class action regarding purported violations of the Telephone Consumer Protection Act.
    • Cumberland Mut. Fire. Ins. Co. v. Express Products, Inc., 529 F. App’x 245 (3d Cir. 2013) — Major role in developing arguments and drafting a successful appellate brief. In holding that the defendant’s appeal was untimely, the Third Circuit confirmed that the time for appeal begins to run upon the issuance of an order granting summary judgment, rather than the issuance of a subsequent memorandum.
    • Pace Communications Services Corp. v. Express Products, Inc., 18 N.E.3d 202 (Ill. App. Ct. 2d Dist. 2014) — Major role in developing arguments and drafting a successful appellate brief, in which the Illinois Appellate Court for the Second District confirmed that the above decision by the Eastern District of Pennsylvania (Cumberland Mut. Fire Ins. Co. v. Express Products) estopped the plaintiffs in the underlying lawsuit from pursuing a subsequent action to recover the policy proceeds.
    • Ins. Fed’n of Pa., Inc. v. Com., Dep’t of Ins., 585 Pa. 630, 889 A.2d 550 (2005) — Primary role in drafting an amicus brief contending that the Pennsylvania Insurance Department did not have the authority to require arbitration of uninsured/underinsured motorist claims. This position was adopted by the Pennsylvania Supreme Court.
  • Publications & Presentations
    • Co-author, Extra-Contractual Litigation Against Insurers, Law Journal Press (2009).
    • Co-author, Behrend, Knowles, and the Continuing Evolution of Class Actions, Nelson Levine de Luca & Hamilton Class Action Quarterly (Spring 2013).
    • Co-author, The Growing Wave of Data Breach Litigation, Risk Management (Dec. 2009).
    • Co-author, Aftermarket Parting Sorrows, Claims Magazine (Aug. 1, 2009).
    • Co-author, After the Storm: Courts Grapple with the Insurance Coverage Issues Presented by Hurricane Katrina, Tort Trial and Insurance Practice Law Journal, Vol. 43, No. 2 (Winter 2008).
    • Co-author, A Duty Everlasting: The Perils of Applying Traditional Doctrines of Spoliation to Electronic Discovery, 12 Rich. J.L. & Tech. 1 (2006) (co-authored with Michael R. Nelson).
    • Co-author, The Impact of “Prohibitive Costs” of Arbitration Upon The Defense of Class Actions, Metropolitan Corporate Counsel (April 1, 2004).
    • Co-author, The Insurance Carrier as Fiduciary: Inappropriate Judicial Lawmaking by Activist Judges in the Context of Regulated Contracts, Federation of Defense & Corporate Counsel Quarterly, Vol. 54, No. 1 (Fall 2003).
  • Education


    J.D., Notre Dame Law School, 2000

    • Articles Editor, Notre Dame Law Review
    • Notre Dame Scholar

    B.A., Government and English, University of Notre Dame, 1997


    Best Lawyers in America® Ones to Watch distinction in Insurance Law (2023-2024)*


    *No aspect of this advertisement has been approved by the Supreme Court of New Jersey. A description of the Best Lawyers selection methodologies can be found at: