Leonard M. Rosenberg is Co-Chair of the firm’s Litigation and Alternative Dispute Resolution practice group and the Medical Staff Credentialing and Governance practice group. Len joined the firm in 1985, and has over 39 years of health care law and litigation experience.

Len represents and counsels clients in federal and state court civil and administrative trials, appeals, arbitrations, hearings, and mediations. His practice includes litigation and pre-litigation counseling in a wide variety of health care, regulatory, commercial and business issues, including medical staff and credentialing matters, contract disputes, directors and officers insurance coverage disputes, and judicial review of agency and other administrative determinations.

Len represents health care systems, hospitals, ambulatory surgery centers, physicians, medical boards and trustees, chief executive officers, chief medical officers, and hearing committees in medical staff credentialing and peer review matters, including intra-hospital hearings and appeals, proceedings before the New York State Public Health and Health Planning Council, and litigation arising from the peer review process. 

Len has also served as hearing committee counsel in dozens of medical staff and medical resident adverse action hearings. Len has extensive expertise and frequently counsels clients in matters involving immunity from liability under the Health Care Quality Improvement Act and health care entities' mandatory reporting obligations to the National Practitioner Data Bank. 

Len has over one hundred court victories in which he successfully defended his clients against claims including age, race, gender, national origin and disability discrimination, defamation, breach of contract, whistleblower claims, tortious interference with contract, and restrictive covenant violations.

Len served as the editor of “In The New York State Courts,” a summary of recent court decisions in health care law for 21 years (2000-2021). The column is a regular feature of the Health Law Journal published by the New York State Bar Association.

Len also served as Chair of the Editorial Board of The Health Lawyer, a journal published by the American Bar Association from 2020-2021, and served as a member and Vice Chair from 2009-2020. Len also served as Vice Chair of Programming of the ABA’s Health Care Litigation and Risk Management Interest Group from 2015-2020, and as Chair of the Nassau County Bar Association Hospital and Health Law Committee from 2019-2022.