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Mark G. Bosswick

CPA, J.D., LL.M., Managing Partner CPA, J.D., LL.M., Managing Partner


Mark G. Bosswick is the Co-Managing Partner of Berdon LLP and has spent his entire 30+ year career at the firm. He integrates the knowledge he has gained as both a CPA and JD to provide comprehensive and practical advice to high-net-worth individuals, their families, and their business interests.

Mark‘s practice focuses on tax and wealth planning with particular emphasis on structuring for closely held businesses and investment vehicles. His work for clients involves a range of matters, from creating tax-efficient wealth transfer structures to addressing income tax issues arising from investments and operating businesses; he also serves as a fiduciary, mediator, and investment consultant to a number of prominent families.

He is a frequent speaker at professional and private family organization events on income tax issues, estate planning and charitable giving and has written on tax matters for various publications. Mark has also served as an expert during litigation proceedings, including real estate, restructurings, bankruptcies, and matrimonial disputes. He was also appointed by the United States Magistrate and the Supreme Court Justice in connection with dissolution and winding-up proceedings.

He works closely with family clients in the following areas:

  • Consulting with multigenerational family-owned business clients on succession planning
  • Representing and administering trusts and estates of real estate and business owners
  • Estate planning using sophisticated wealth-transfer techniques
  • Serving on investment committees of family groups and business entities
  • Developing and monitoring overall wealth-preservation investment strategies conforming with the standards of the Prudent Investor Act and Uniform Principal and Income Act
  • Mediating, negotiating, and structuring partnership, shareholder, and buyout agreements

His experience in the real estate arena includes:

  • Advising on restructuring debt
  • Planning and structuring joint venture arrangements, including property development
  • Advising and negotiating sales and acquisitions
  • Formulating lease arrangements
  • Acquiring mortgages and related REOs
  • Developing creative approaches for like-kind exchanges


American Institute of Certified Public Accountants

Association for a Better Long Island, Associate Member

New York State Bar Association

  • Tax Section
  • Trust and Estate Law Section

New York State Society of Certified Public Accountants

Real Estate Board of New York, Allied Member

Mark has been quoted in publications, among them Crain’s New York Business and Long Island Business News, on techniques to acquire, hold, and transfer real estate; strategies to sell a business; and ways to reduce estate taxes.


Mark holds a Bachelor of Science degree in accounting, cum laude. He received a Juris Doctor degree from Brooklyn Law School and a Master of Laws degree in taxation from New York University School of Law.  In 1984, he obtained his license as a Certified Public Accountant in New York. Mark was admitted to practice law before the Courts of New York in 1987 and the United States Tax Court in 1988.