The Gassman & Gassman Tax Team

Jonathan Gassman, CPA/PFS, CFP®, CAP®

Founder of The Gassman Financial Group

Jonathan Gassman, CPA/PFS, CFP®, CAP®, is the CEO and founder of The Gassman Financial Group, a New York City-based public accounting firm, and is co-founder of G&G Planning Concepts Inc., a financial planning firm, which, through the years, has evolved to be one of the leading wealth management firms in New York City.  G&G Planning Concepts, Inc. is an outgrowth of the original firm founded in 1926. The third-generation, family-owned firm passed from Grandfather Alexander Gassman to Father Mel Gassman to Grandson Jonathan Gassman in a succession that embodies the way the firm  lives up to its reputation as a  business that knows how to take care of its clients.  In the early 1990’s, Jonathan Gassman expanded the firm to encompass financial planning. Jonathan is also the co-founder and CEO of The Business Owners Resource Group, a team of highly skilled financial planners, attorneys, accountants, and bankers.
A professional who acts as a chief financial advisor to many highly respected professionals, Jonathan has taken his knowledge and experience as a certified financial planner and a certified public accountant to consistently provide the highest level of service to his clients. Jonathan’s long-term involvement with charitable planned giving is what led him to pursue the rigorous CAP® credential (Chartered Advisor in Philanthropy®).  The CAP® program provides financial professionals with the knowledge and tools needed to help clients reach their charitable giving objectives, while also helping them meet their estate planning and wealth management goals. Only 350 individuals have been awarded the prestigious CAP® designation since its inception in 2003. 
The core financial planning services of G & G Planning Concepts Inc. include estate and tax planning, insurance, investment planning, retirement planning, and employee benefit planning. The firm offers many other specialized services that range from estate succession planning for business owners, and stock option planning, the utilization of philanthropic planning to create more wealth and cash flow, and delivering comprehensive investment solutions.
Jonathan received his education at the Long Island University/CW Post Center for undergraduate and graduate school, where he earned B.S. and MST degrees. Jonathan has earned his CFP® designation from the Certified Financial Planner Board of Standards, Inc. He earned the (CAP®) professional designation from the Richard D. Irwin Graduate School of The American College, Bryn Mawr, Pennsylvania. He received additional professional training through the Rainmaker Academy, the Strategic Coach Program, the Values Based Planning Academy, and the Renaissance Charitable Giving Foundation. Jonathan has been a member of The American Institute of CPA's, The Financial Planning Association, New York State Society of CPA's, National Committee on Planned Giving, Planned Giving Group of Greater New York, and the Estate Planning Council of NY. He is a frequent participant in both the AICPA and FPA conferences.


Stefanie Greenberg, CPA, MST

Controller and Tax Accountant

Stefanie is a seasoned tax professional with 25 years of experience in individual, corporate, partnership, and trust tax. A long-time employee of the firm, she is primarily responsible for overseeing work done on behalf of the firm’s corporate and business clients. In this role, she serves as a trusted advisor to a wide variety of businesses, foundations, and trusts. Stefanie is highly effective at managing numerous roles and responsibilities, and serves as the firm’s controller and a mentor to the firm’s newest staff members.

Stefanie began her career as an auditor with a prestigious CPA firm in New York City, where she honed her skills by serving a wide variety of business and corporate clients. Stefanie is a Certified Public Account (CPA) and earned a B.B.A. Degree in business from Hofstra University and a M.S. in tax from Long Island University, C.W Post Campus.

A native of Long Island, Stefanie resides in Searingtown, NY, with her family. She is active in her local Parent Teacher’s Association and enjoys traveling and playing tennis.


Shamsul (Tunu) Islam

Tax Accountant & Preparer

Shamsul (Tunu) has more than 30 years of hands-on experience preparing personal tax returns. Highly analytical and insightful, Tunu has helped clients from every walk of life navigate the personal tax code with his trademark good spirit and humor. He is a treasured, long-time member of the firm and was hired and trained personally by Mel Gassman—the former owner of Gassman & Gassman CPA, our predecessor firm. 

Tunu advises hundreds of the firm’s clients each year with matters involving personal tax planning, tax projections, payroll taxes, IRS correspondence, and personal tax audits. After recently celebrating his 30th year with the firm, Tunu successfully passed the first of three examinations required for the Enrolled Agent (EA) designation.

Tunu was born in Bangladesh and graduated with a B.S. degree in sociology from the University of Dhaka, the oldest research university in Bangladesh. Shortly after, he came to the United States and studied accounting at Queens College. Tunu lives with his wife and two children on Long Island. He enjoys a variety of sports such as basketball, cricket, and soccer, and fulfils his creative spirit by painting and playing the guitar and piano.


Gabrielle (Yue) Leng, CPA

Tax Associate

Gabrielle Leng is a Tax Associate with Gassman & Gassman, CPA P.C. In this role, she supports the firm’s tax practice by researching a variety of tax related questions, responding to government correspondence, and assisting in the preparation of individual and corporate tax returns.

She is a graduate of Baruch College, earning her Master of Science degree in Accounting. She achieved high academic honors at Baruch while maintaining full-time employment. In addition to her academic accomplishments, Gabrielle was active in several graduate school clubs, including her role as Vice President of Membership in the Graduate Beta Alpha Psi-one of the three largest club affiliations within Baruch College.

Prior to joining Gassman & Gassman, CPA P.C., Gabrielle worked at the Sony Corporation of America as a tax intern. Her responsibilities at Sony exposed her to a variety of areas related to corporate taxation including property tax filing and the preparation of corporate income tax returns for Sony and its affiliated entities. Prior to Sony, she worked in a small CPA firm as a seasonal associate; assisting clients with bookkeeping, payroll tax and individual tax matters.

Fluent in Mandarin, she enjoys cooking, baking, digital photography and Alpine Slalom Skiing.


Nydia Lugo

Chief of Operations

A recent addition to the firm, Nydia brings with her a wealth of experience as a senior level administrator and bookkeeper for several top public accounting and executive search firms. She is responsible for supporting the firm’s leadership and professional staff, and managing the day-to-day operations of the office. She completed coursework in liberal arts with a concentration in business administration at Hostos Community College, and studied bookkeeping through New York University’s Professional Studies program.

Nydia joins us from Perelson Weiner, LLP where she served as an administrative assistant to three of the firm’s senior tax partners. She has also worked at Major, Lindsey & Africa, an executive search firm serving the legal field, and Hunt Howe Partners, LLC, an executive search firm catering to Fortune 100 firms. In these roles, Nydia was responsible for enhancing various processes that would improve workplace efficiency and make it possible to more effectively serve clients. She sees client satisfaction as “the only key operating metric that matters” and brings to the job a keen eye for overall efficiency and workplace aesthetics.

Fluent in Spanish, Nydia enjoys travel, fashion, and spending time with friends and family.