Stuart Hammer is a member of the firm’s Corporate Department and the head of its Environmental Practice Group. For more than two decades, he has advised prominent corporations, private equity firms and other entities on environmental matters in mergers and acquisitions, joint ventures, financings, securities offerings and other transactions. He has counseled clients on the environmental risks associated with hundreds of transactions involving facilities in the United States and overseas. Mr. Hammer has also advised companies on environmental proceedings and issues related to climate change.

Mr. Hammer is consistently ranked as a leader in environmental law. He is a leading lawyer for the Environment: Mainly Transactional category by Chambers USA (2019), in which clients laud him for being “a commercial, practical and surgical practitioner, as well as a good listener.” In the 2018 edition of the guide he is described as being “very thorough and extremely timely,” and in Chambers USA (2017) clients praised him for his “effective knowledge and good communication.” Mr. Hammer is described as “top-notch” and “very practical in his advice and takes time to ask the pertinent questions” (Chambers USA (2016)). He is also recommended in The Legal 500 US (2019) where they note he ‘brings a clear passion to his work’ and ‘helps clients understand and mitigate risk’. Mr. Hammer is recognized by Best Lawyers in America (2018), Super Lawyers (2018) and Who’s Who Legal (2018) as a leading environmental lawyer. Additionally, The National Law Journal (2017) lauds Mr. Hammer as a Trailblazer for Energy & Environmental.

Mr. Hammer has authored and co-authored numerous articles on environmental and climate change issues, including “Don’t Ignore The Smoke Signals,” Private Funds Management (February 2017); “Climate Change Related Laws in the U.S. — What to Expect Under the New Administration,” LexisNexis Japan Business Law Journal (February 2017); “New Administration’s Environmental Policies Unlikely to Undermine Investor ESG Focus,” Pensions & Investments (January 20, 2017); “Greener Pastures,” Private Equity International (December 26, 2016); “Weighing Pros And Cons Of EPA's Audit Policy,” Law360 (April 1, 2015); “How Companies Can Manage Environmental Reputational Risk,” Business Ethics (April 9, 2014); “Climate Change Disclosure,” NACD Directorship (July 26, 2011); “Climate Change Disclosure Obligations for Insurers,” Insurance Law360 (February 11, 2011); “Effects of EPA Clean Air Initiatives,” Environmental Law360 (December 2, 2010); “What to Know in the Absence of a Climate Change Law,” Environmental Law360 (August 11, 2010); “The NAIC Produces Revised Climate Change Risk Disclosure Survey,” The Debevoise & Plimpton Financial Institutions Report (June 2010); “Climate Change Issues Are Turning Up the Heat on Businesses in the U.S.,” The Debevoise & Plimpton Private Equity Report (Winter 2010) (reprinted in Private Equity Manager (April 2010)). Mr. Hammer contributed a chapter to PLI's Healthcare Mergers & Acquisitions Answer Book 2018.

Mr. Hammer joined Debevoise in 1992. He received his B.A. magna cum laude from Yeshiva University in 1988 and his J.D. from Cardozo Law School in 1992.


  • Yeshiva University, Benjamin N. Cardozo School of Law, 1992, J.D.
  • Yeshiva University, 1988, B.A.

Bar Admissions

  • New York