John Zen Jackson

Of Counsel

Iselin

T: 732.476.3336

F: 732.476.3337

jjackson@greenbaumlaw.com

Professional liability claims, licensure and credentialing disputes, reimbursement disputes, insurance coverage and insurance fraud matters, hospital privilege disputes
Certified by the Supreme Court of New Jersey as a Civil Trial Attorney; represents healthcare providers in disputes before judicial forums, state administration agencies, and hospital credentialing committees
Highly knowledgeable in issues related to medical liability, professional regulations and licensure, biomedical ethics, and end-of-life concerns

John focuses his practice on civil litigation including trial and appellate advocacy, primarily in the healthcare area, as well as in healthcare regulatory and compliance matters. He has represented healthcare providers in the defense of professional liability claims, licensure and credentialing disputes, reimbursement disputes, insurance coverage and insurance fraud cases, qui tam actions under the Federal False Claims Act, and hospital privilege disputes including termination litigation. He has been responsible for matters involving medical staff privileges at the internal hearing level and in subsequent court litigation. He has additional experience as a hearing officer in hospital privilege disputes and in drafting medical staff bylaws. He has authoritative expertise in medical liability, biomedical ethics, and end-of-life issues.

Certified by the Supreme Court of New Jersey as a Civil Trial Attorney, John has litigated matters in judicial forums, trying numerous jury trials to verdict, and has appeared extensively before state administrative agencies and hospital credentialing committees. He has assisted healthcare entities seeking to outsource the handling of physician investigations, and physicians facing investigative inquiries and disciplinary charges before the Board of Medical Examiners (BME). He handles the full range of BME proceedings, including responding to an initial inquiry and appearing at a preliminary evaluation, responding to Orders to Show Cause and temporary suspension applications, hearings in the Office of Administrative Law (OAL), addressing the BME on disposition and discipline issues, argument of appeals before the Appellate Division, and appearances before the New Jersey Supreme Court.

Results may vary depending on your particular facts and legal circumstances.

Areas of Focus

Practice Areas

Litigation

Healthcare Litigation

Healthcare

Healthcare Regulatory & Compliance

Managed Care Contracting & Dispute Resolution

Professional Negligence, Malpractice & Ethics

Insurance Coverage

Criminal Defense & Regulatory Compliance

Industries

Healthcare

Credentials

Bar Admissions

New Jersey, 1975
New York, 2005
U.S. District Court, District of New Jersey, 1975
U.S. District Court, Southern District of New York, 2008
U.S. District Court, District of Columbia, 2015
U.S. Supreme Court, 2007
U.S. Court of Appeals, Third Circuit, 1987
U.S. Court of Appeals, D.C. Circuit, 2016

Education

Seton Hall Law School, J.D., 1975
Tufts University, B.A., 1972

Recognition

American College of Trial Lawyers Fellow: Legal Ethics and Professionalism Committee
Listed in The Best Lawyers in America (a trademark of Woodward/White, Inc.) in the Commercial Litigation, Medical Malpractice Law - Defendants, and Litigation - Health Care practice areas (2009 - present)
Selected by Best Lawyers (a trademark of Woodward/White, Inc.) as Newark "Lawyer of the Year" in Medical Malpractice Law-Defendants (2021); as Newark "Lawyer of the Year" in Litigation-Health Care (2020, 2018); as Newark "Lawyer of the Year" in Medical Malpractice Law - Defendants (2019, 2015, 2012)
Listed in New Jersey Super Lawyers (a Thomson Reuters business) in the Health Care, Personal Injury - Medical Malpractice: Defense, Administrative Law, and Business Litigation practice areas (2005-present); listed as one of Super Lawyers’ Top 100 Attorneys in New Jersey (2010-2011)
Martindale-Hubbell Peer Review Rated AV Preeminent (a trademark of Internet Brands, Inc.)
Recipient of the Trial Bar Award from the Trial Attorneys of New Jersey for his distinguished service in the cause of justice (2014)

Please visit our Award Methodology page for a description of the standard or methodology on which these accolades are based. Attorney Advertising: No aspect of this advertisement has been approved by the Supreme Court of New Jersey.

Clerkships

Former law clerk to The Hon. Richard J. Hughes, Chief Justice of the New Jersey Supreme Court (1975-1976)

Experience

Representative Matters

The firm’s team represented a coalition of New Jersey hospitals in a $300 million constitutional challenge to the State of New Jersey’s charity care and Medicaid reimbursement regime, defending the hospitals’ takings claims through summary judgment, Appellate Division review, and New Jersey Supreme Court proceedings, resulting in published decisions affirming dismissal of the claims. The hospitals filed a petition for certiorari with the Supreme Court of the United States, which was denied.
Represented a New Jersey healthcare system and its Chair of Surgery in litigation brought by a trauma surgeon challenging a summary suspension of medical staff privileges. Following reinstatement through internal proceedings, the firm continued to defend the client in this $2.4 million action, which settled before trial.
Represented a New Jersey healthcare system in defense of fraud, breach of contract, age discrimination, and CEPA retaliation claims brought by three physicians and their surgical group seeking more than $9 million.
Representing two New Jersey health systems in high-stakes litigation against multiple Medicare Advantage plans seeking recovery of approximately $5 million in underpaid 340B drug reimbursements, following a U.S. Supreme Court decision invalidating the Center for Medicare and Medicaid Services’ reimbursement reductions; matters are proceeding toward mediation and arbitration.
Representation of a major healthcare system in litigation brought by a former physician alleging wrongful termination of privileges and antitrust and Lanham Act violations, resolving the matter through a favorable settlement.
Represented a New Jersey healthcare system in defense of antitrust and tort claims brought by a pediatric surgeon following revocation of privileges, securing a negotiated resolution.
Representing the State of New Jersey, Department of Children and Families and Department of Corrections in a series of high-exposure cases arising under extended statutes of limitations involving claims of alleged child sexual abuse. The potential aggregate exposure across these matters approaches $1 billion, with certain cases expected to resolve through settlement or high/low agreements.

Affiliations

Memberships

Trial Attorneys of New Jersey: former President (1999)
New Jersey State Bar Association: Health Law Section; Civil Trial Bar Section
Medical History Society of New Jersey: President (2026-2027)

Committees

Penn Medicine Princeton Health: Biomedical Ethics Committee
New Jersey Supreme Court District Ethics Committee for District VII (Mercer County), which is charged with investigating and prosecuting alleged violations of attorney ethics rules by members of the New Jersey Bar (2025-2029)
New Jersey Supreme Court Board on Attorney Certification; Chair (2008-2011)
New Jersey Supreme Court Civil Certification Committee: Chair (2008-2011); member (1997-2011)
New Jersey Supreme Court Board on Continuing Legal Education (former member)

Other Activities

Served on the Editorial Board of MDAdvisor, a peer-reviewed journal for the New Jersey medical community, from its inception in 2007 until the discontinuation of publication in 2023