.

G. Mark Thompson

President & CEO

Chairman, Executive Committee

GMThompson@mdwcg.com

Portrait of G. Mark Thompson

As President and CEO of Marshall Dennehey, Mark is responsible for the day-to-day management and business strategy of the firm which consists of 500 attorneys operating out of 19 offices throughout Pennsylvania, New York, New Jersey, Connecticut, Delaware, Ohio and Florida. He was elected to the position in December of 2017 after serving more than three years on the Executive Committee and a decade on the Board of Directors. He succeeded Tom Brophy who served in the role for 13 years.

Mark is joined by a management team comprised of two other senior executives, a Board of Directors, managing attorneys from every office, practice group supervisors, administrative directors and over 1,000 employees who combine their talents to develop and implement the strategies and achieve the objectives of the firm and its clients.

Prior to moving to the firm's Philadelphia headquarters in 2014, Mark also served as the regional managing attorney for its four Florida offices. A Florida native, it was there he built a reputation as a "go to" attorney advising Fortune 500 clients in high profile, high exposure and often crisis  situations. During his career he has handled matters that attracted international media attention, are the subject of books, a documentary film and in one instance a hearing before the US House of Representatives in Washington DC, at which Mark represented one of the corporations testifying.

Mark has more than 30 years of experience in the legal profession, is rated AV Preeminent by Martindale Hubble, was recognized in 2006, 2007, 2013 and 2014 as a Florida Super Lawyer and in 2012 as one of Florida's Legal Elite by Florida Trend magazine. He is admitted to practice before the Florida Supreme Court, the United States Court of Appeals for the Eleventh Circuit and the United States District Court for the Middle District of Florida. He has tried cases in county, circuit, and federal courts and argued before the District Courts of Appeal. In 2012 he also became licensed to practice in Pennsylvania.

Prior to attending law school, Mark spent two years working as an insurance adjuster. The experience continues to inform his understanding of the critical needs of claims professionals.

His civic activities include serving on the Board of Directors of Christian Legal Clinics of Philadelphia, a legal aid organization assisting the disadvantaged, whose north Philadelphia clinic was started and is staffed every month by Mark and his colleagues from Marshall Dennehey. Mark also has served on the Grants Committee of the Philadelphia Bar Foundation.

    • Cumberland School of Law (J.D., 1989)
    • University of Florida (B.A., 1984)
    • Florida, 1989
    • U.S. District Court Middle District of Florida, 1990
    • U.S. Court of Appeals 11th Circuit, 1998
    • Pennsylvania, 2012
    • Supreme Court of the United States
    • AV® Preeminent™ by Martindale-Hubbell®
    • Florida Super Lawyers (2006-2007, 2013-2014)
    • Florida Trend Magazine's Florida Legal Elite, 2012
    • Pennsylvania Super Lawyers (2018-2022)
    • Claims & Litigation Management Alliance (CLM)
    • Defense Research Institute
    • International Amusement & Leisure Defense Association
    • International Association of Amusement Parks and Attractions (IAAPA)
    • Orange County Bar Association
    • The Best Offense is a Good Defense: Managing Liability Claims in Today's Litigious Environment, Business Insurance Webinar, August 12, 2015
    • The Claim Management Link: Interplay Between Risk Tolerance, Operational Structure, Litigation and Claim Outcomes, CLM Annual Conference, March 2015
    • Florida Premises Liability - Investigation and Defense
    • Florida Liquor Liability
    • Spoliation of Evidence
    • Defended a corporation and obtained summary judgments in multiple federal lawsuits alleging sponsorship, production, distribution and sale of videos depicting plaintiffs' underage participation in various spring break contests.
    • Defended a manufacturer and obtained satisfactory confidential resolution of claims brought by 51 factory employees alleging toxic exposure.
    • Defended a state agency and obtained defense verdict in wrongful death trial alleging inadequate traffic control.
    • Defended a major insurer and obtained defense verdict in trial brought by owner of an oddities museum whose collection and building was completely destroyed by fire.
    • Defended a tourist destination and obtained summary judgment in a negligence action brought by a contracted performer rendered quadriplegic as a result of an accident during a gymnastic slam dunk exhibition.
    • Defended a company and obtained defense verdict on appeal in lawsuit alleging bottle "exploded" while being handled by plaintiff.
    • Defended a tourist destination and obtained defense verdict in trial alleging inadequate slip resistance of drainage grates.
    • Defended and settled numerous lawsuits involving tractor trailer rollovers allegedly caused by improper loading of cargo.
    • For nearly 20 years, defended theme parks and tourist destinations throughout Florida in hundreds of cases involving amusement rides, wild animals, negligent security, E-coli outbreaks, slip and falls, defamation, food poisoning, false imprisonment and matters of intellectual property.
    • Anheuser-Busch, Inc. v. Lenz, 669 So.2d 271 (Fla. 5th DCA 1996)
    • Becton v. Metal Container Corp., 856 So.2d 982 (Fla. 1st DCA 2003)
    • Jordan v. Sea World of Florida, Inc., 938 So.2d 991 (Fla. 5th DCA 2006)
    • Badillo v. Anheuser-Busch, 19 Fla. L. Weekly Fed. D 641 (M.D. Fla. 2006)

Thought Leadership

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Media Commentary

G. Mark Thompson Quoted in The American Lawyer Article on Staffing in Defense Industry

August 15, 2024

Media Commentary

Marshall Dennehey President & CEO Featured on Cover of Best's Review

May 1, 2024

Marshall Dennehey President & CEO G. Mark Thompson was featured on the cover of the May 2024 issue of Best's Review and quoted in the article, "For the Defense."

News

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Firm Highlights

Thought Leadership

Commonwealth Court Reaffirms the Constitutionality of Act 111's IRE Provisions

In this case, the claimant sustained a work injury of January 6, 1994, which was acknowledged by Notice of Compensation Payable (NCP). After the claimant’s receipt of 104 weeks of temporary total disability benefits, the employer filed a Request for an Impairment Rating Examination (IRE). The IRE was performed in May 2023 and the IRE physician found that the claimant had a 5% whole person impairment, under the AMA Guides. The employer filed a Petition based on the IRE results, and the Petition was granted by the WCJ. During litigation, the claimant argued that the IRE provisions of Act 111 (Section 306(a.3) of the Act) were not applicable to her injury, since it predated June 24, 1996, the date Act 57 went into effect, and that the IRE provisions were unconstitutional. The Workers’ Compensation Judge (WCJ)) granted the Petition and the Board affirmed. On appeal to the Commonwealth Court, the claimant argued that Act 111 violated the nondelegation doctrine and that its retroactive application to the claimant’s injury was unconstitutional. The court rejected the arguments on the basis that they had already found the same arguments without merit in multiple, prior cases. The court also addressed an argument made by the claimant that Act 111 was procedurally defective under the Pennsylvania Constitution because it was only considered on two days in each House after having undergone amendments and reassignments. The court noted that the Pennsylvania Constitution requires every bill to be considered on three different days in each House. The claimant maintained that, according to the legislative history, the bill did not receive three separate days of consideration from each House when it was assigned a new bill number. The court pointed out, however, that the bill number, H.B. 1840 remained constant and was considered on three occasions by the House. Further, the court concluded that minor amendments to the bill were germane to its original subject, which was to modify the Act’s IRE process, in accordance with Protz II.

Bret E. Dubbert Joins Marshall Dennehey’s Orlando Office as Special Counsel in the Casualty Department

News

Bret E. Dubbert Joins Marshall Dennehey’s Orlando Office as Special Counsel in the Casualty Department

Result

$19 Million Medical Malpractice Verdict Overturned

In this medical malpractice case, the trial court vacated $10 million of a $19 million verdict in post-trial motions and the Superior Court of Pennsylvania vacated the remaining $9 million on appeal.

Thought Leadership

WCJ Improperly Refused to Conduct C&R Hearing and Erroneously Required Settlement of All Pending Petitions

In this case, the claimant sustained injuries in the course and scope of her employment as a registered nurse. The employer acknowledged the injury by a Notice of Compensation Payable (NCP).  Subsequently, a Workers’ Compensation Judge (WCJ) expanded the description of injury. The employer then filed a Termination Petition, alleging the claimant was fully recovered from the injuries. Providers filed Utilization Review (UR) Petitions, challenging UR determinations finding their chiropractic treatment to be not reasonable and necessary. A settlement of the claim was eventually reached, and the employer filed a Petition to Seek Approval of a Compromise and Release (C&R) Agreement. The C&R outlined that the agreement fully resolved all future workers’ compensation claims except for the termination and UR Petitions. Briefs were filed and one day later, the WCJ issued an Interlocutory Order which stated if instructions were not followed regarding filing of a C&R, a settlement hearing date would not be given. The employer complied with the order, and filed the C&R. Subsequently, the WCJ notified the parties that the C&R must resolve all issues in the petitions, or would not be entertained. A settlement hearing was never held, and the WCJ then issued a decision, granting the Termination Petition and dismissing the UR Petitions. The WCJ also said that the Petition for Approval of a C&R was dismissed without prejudice, as the issues in the Termination and UR Petitions went to a decision. The claimant appealed to the Workers’ Compensation Appeal Board (Board). The Board granted the claimant’s appeal, finding that the WCJ violated the requirement of Section 449 that an expedited hearing be held when a Petition for Approval of a C&R is filed.  The Board further held that it was legally incorrect for the WCJ to insist that the C&R resolve all issues raised by the pending Petitions. The Board remanded the case to a new WCJ, and Employer appealed to the Commonwealth Court. The court affirmed the Board and held that the WCJ erred, as a matter of law, by refusing to hold an expedited hearing within 30 days, once the Petition for Approval of a C&R was filed.  The court noted that the language of Section 449(b) is mandatory, and a settlement hearing is not discretionary or dependent on a party’s separate request for a stay, or whether the record has been closed. The court further rejected Employer’s argument that the case should not be remanded to a new WCJ for a new decision on the termination and and UR Petitions, as the Board passed no judgment on whether the C&R Agreement resolved the termination and UR Petitions, and left it for the WCJ to decide in connection with the Petition for Approval of a C&R.

Marshall Dennehey Named a Standout in Litigation by BTI Consulting Group

News

Marshall Dennehey Named a Standout in Litigation by BTI Consulting Group

Result

$1.09 Billion Products Liability Verdict Overturned

In this products liability crashworthiness case, the Superior Court of Pennsylvania reversed a Philadelphia jury verdict of $1.09 billion, the largest verdict ever overturned by a PA appellate court.  The court ordered a new trial based on deficient jury instructions, clarified important aspects of crashworthiness law, and confirmed that so-called standard jury instructions may be incompatible with Pennsylvania law. 

Result

Statutory Employer Immunity Upheld

In this construction accident case that resulted in a $5 million verdict, the Supreme Court of Pennsylvania upheld the Statutory Employer Doctrine, which immunizes general contractors and other contractors on construction sites when certain elements are satisfied.

Event

CLM 2026 Focus Conference

Allison joins three insurance industry leaders to discuss how cyber coverage disputes, the growing impact of social inflation on bodily injury claim valuation, and the use of artificial intelligence are reshaping the bad faith landscape. The panel will examine emerging sources of extra-contractual exposure, including evolving cyber insurance coverage issues and the challenges of accurately valuing bodily injury claims. Practical approaches to claim evaluation using AI, along with defense strategies designed to help prevent or successfully defend against bad faith litigation, will also be addressed. 

graphic announcing our 6 2027 Super Lawyers & Rising Stars

News

Marshall Dennehey Announces 2027 New Jersey Super Lawyers And Rising Stars

Thought Leadership

Appellate Division Reversed Trial Judge's Orders Granting a Plaintiff's Section 40 Summary Judgement Motion

In Haskins v. Casey, et al., the plaintiff Dane Haskins worked for defendant Ekornes, Inc. (Ekornes) as a material handler. In June 2021, he filed a workers’ compensation claim petition for benefits due to a left shoulder injury in December 2020. He then resolved his workers’ compensation claim in November 2022 under an Order Approving Settlement. In January 2023, he filed a lawsuit against Ekornes and later amended to add additional claims and name other defendants, including the Ekornes president, chief financial officer, and director of human resources. In May 2025, a second amended complaint alleged that after he filed the workers compensation claim, Ekornes placed him on leave under the Family and Medical Leave Act (FMLA), denied his request for a work accommodation, and ultimately terminated him from employment in December 2021. He pleaded several causes of action asserting violations of the New Jersey Law Against Discrimination (LAD) as well as fraudulent concealment and wrongful discharge. The plaintiff then moved for partial summary judgment, seeking an order enforcing Section 40 of the Workers’ Compensation Act (WCA) as well as summary judgment on his FMLA claims. The defendants opposed the motions and cross-moved for summary judgment on the FMLA claims. After arguments, the court entered an order in December 2025, denying the FMLA motion and cross motion and granting the plaintiff’s Section 40 motion. In the order, the court permitted the plaintiff to pursue compensatory damages at trial in connection with the bodily injury claim. The court also allowed the plaintiff to present evidence of any workers’ compensation benefits to support his claim. The court then denied the defendant's subsequent reconsideration motion in February 2026. The defendants that appealed the Section 40 aspect of the orders. In reviewing the appeal de novo, the Appellate Division rejected the plaintiff's argument that the work-related injury arose out of his discrimination claims under the LAD. The plaintiff argued that he should be able to pursue a personal injury claim as a part of his LAD claim, noting that the employer’s compensation carrier would be able to assert a lien against any recovery against his LAD claims. In distinguishing between the Richter vs. Oakland Board of Education, 246 N.J. 507 (2021) case, in which the Court found that any recovery would be subject to a Section 40 lien as the allegation was that the defendants failed to accommodate her pre-existing diabetic condition, which resulted in bodily injury. In this case, the Appellate Division indicated that there was no bodily injury caused by Ekornes’ failure to accommodate a pre-existing disability. Rather, the shoulder injury was a result of a workers compensation claim, for which he received appropriate benefits previously. The Appellate Division noted that if the plaintiff was successful in proving his LAD claims, he would be entitled to damages caused by the discriminatory discriminatory conduct such as lost wages and emotional distress damages and that there will be no Section 40 lien. In addition, the Appellate Division disagreed that the petitioner could present evidence about and seek damages for his shoulder injury at trial. Although the petitioner argued that a defendant who retaliated against an employee for filing a workers’ compensation claim should not benefit from the exclusivity provision of the WCA, the Appellate Division noted that the Legislature did not include this type of scenario in the statue nor did any of the case law recognize this type of claim as a remedy. As such, the Appellate Division reversed the December 2025 order granting the the plaintiff’s Section 40 summary judgment motion as well as the February 2026 reconsideration motion order. The Appellate Division noted that they did not intend to limit the plaintiff in his pursuit of his other claims on under the LAD, FMLA, and workers’ compensation retaliation causes of action.