Gregory Eisenstark



(973) 200-7411

(973) 200-7510

Greg has wide-ranging experience representing public utilities, unregulated energy companies, electric generation companies, educational and governmental institutions, and other industry participants. He  maintains a comprehensive energy and utility regulatory and transactional practice, with expertise in base rate cases, rate clause filings, reliability issues, public utility project siting petitions and appeals, mergers and acquisitions, renewable energy (including solar and offshore wind projects), demand response and energy efficiency issues, regulatory audits, provider of last resort and competitive third-party supplier issues, and utility financing issues. He has experience in administrative rulemaking, drafting legislation, and counseling on energy policy issues, as well as appellate experience in both state and federal courts. 
Greg has litigated hundreds of utility rate and regulatory filings to successful completion. Since the early 1990s, he has handled many base rate cases involving water, wastewater, natural gas, and electric utilities. 
Prior to private practice, Greg served as associate general regulatory counsel for Public Service Enterprise Group (PSEG), where he represented PSEG's operating companies in regulatory matters before the New Jersey Board of Public Utilities, the Federal Energy Regulatory Commission, other state utility commissions, and in state and federal courts. Earlier in his career, Greg was managing attorney – electric for the New Jersey Division of Ratepayer Advocate, where he represented utility customers in matters before regulatory agencies and courts. In that capacity, Greg played an active role in the transformation of the PJM Interconnection from a power pool to an independent system operator. Before that, Greg was a deputy attorney general of New Jersey, where he represented the Board of Public Utilities and Department of Environmental Protection in utility and solid waste industry matters.
Greg has been elected to The Best Lawyers in America. He was selected by Best Lawyers as its central New Jersey Lawyer of the Year for Energy Law in 2019 and 2021. 
Greg earned his bachelor’s degree from Oberlin College. Greg earned his law degree from Rutgers University School of Law - Newark.



More Than 200 Cozen O’Connor Attorneys Named Best Lawyers and Ones to Watch By The Best Lawyers In America

August 20, 2020

Best Lawyers selected 201 Cozen O’Connor lawyers from 23 of the firm’s nationwide offices for inclusion in the 2021 edition of The Best Lawyers in America© (Copyright 2020 by Woodward/White, Inc., of Aiken, SC).

Nine Cozen O’Connor Lawyers Named 2021 “Lawyers of the Year” by Best Lawyers in America

August 20, 2020

Cozen O’Connor is proud to announce that nine of the firm’s lawyers have been recognized as “Lawyers of the Year” in their respective practices by Best Lawyers in America.

Cozen O’Connor Announces Hiring Two Nationally Renowned Energy Lawyers and Continues Expansion of its U.S. Footprint, Opening a Newark, N.J. Office

April 01, 2019

Gregory Eisenstark and Michael J. Connolly join Cozen O’Connor and will lead the Newark office


New Jersey’s First in the Nation State Environmental Justice Law [Alert]

October 22, 2020

Amorie Hummel, Evan Preminger, Michael Connolly, and Greg Eisenstark discuss the New Jersey law that is the first in the nation to require mandatory permit denials under state law for new facilities and to expressly allow the imposition of conditions on renewal and expansion permits for existing facilities based on environmental justice concerns alone.

NJBPU Approves Year 2 Application Process for Community Solar Energy Pilot Program [Alert]

October 13, 2020

Michael Connolly and Greg Eisenstark discuss the NJBPU's Community Solar Program Year 2 application process. Applications for Year 2 community solar projects are due by February 5, 2021.

Voluntary Moratorium on New Jersey Utility Shut-offs Extended to October 15, 2020 [Alert]

September 01, 2020

Gregory Eisenstark and Michael J. Connolly discuss the voluntary moratorium on utility shut-offs for non-payment of bills that Gov. Murphy extended to October 15, 2020. The moratorium applies to electric, gas, water, and wastewater utilities regulated by the New Jersey Board of Public Utilities.

N.J. EO-127 Extends Contested Case, Rule Deadlines — May Impact Utilities, Other Regulated Entities [Alert]

April 20, 2020

Greg Eisenstark and Michael Connolly discuss New Jersey's executive order extending deadlines until after the public health emergency.

COVID-19 and the Utility, Energy, Telecommunications & Transportation Sectors: What [Alert]

March 24, 2020

David Zambito, Michael Klein, Michael Connolly, Gregory Eisenstark, Ira Megdal, and Jonathan Nase discuss the executive orders in New Jersey and Pennsylvania impacting the utility industry.


  • Rutgers University School of Law—Newark, J.D., 1991
  • Oberlin College, B.A., 1984

Awards & Honors

The Best Lawyers in America, Energy Law, 2016-2021

The Best Lawyers in America, Lawyer of the Year for Energy Law, 2019, 2021

  • New Jersey
  • New York
  • Pennsylvania
  • U.S. Court of Appeals for the Third Circuit
  • U.S. Court of Appeals for the District of Columbia Circuit
  • U.S. District Court -- New Jersey

American Bar Association

New Jersey State Bar Association, Public Utility Law Section

New Jersey Utilities Association