About Diane

Diane Giordano is a partner in the Tax & Business Services division in the Firm’s Melville, New York office. She works closely with large, multi-state companies as well as family-owned businesses, providing tax and tax credit consulting, financial statement disclosure, and compliance services. Diane’s clients also include U.S. Securities and Exchange Commission (SEC) reporting entities for which she provides various tax provision services.

Diane has more than 25 years of accounting and tax experience. She frequently speaks to professional and industry organizations on a variety of tax topics and authors numerous articles that have been published in various professional publications.

Additionally, she serves as the editor of the Firm’s tax newsletter, Beyond the Numbers, Firm-wide Tax Flashes, social media publication content, and the annual Marcum Year-End Tax Guide.

Diane is also a leader in the Firm-wide integration process and is a frequent instructor on various tax technical topics, including tax credits and net operating losses.

Prior to joining Marcum in 2005, she worked at other global and large accounting organizations.

Professional & Civic Affiliations

  • American Institute of Certified Public Accountants (AICPA)
  • New York State Society of Certified Public Accountants (NYSSCPA)
  • Moxxie Network
  • Half Hollow Hills Business Partnership
  • Mentoring Partnership of Long Island, Advisory Board
  • Long Island Alzheimer Foundation, Past Committee Member
  • Mentoring Partnership of Long Island, Past Advisory Board Member
  • Girls, Inc. of Long Island, Past Board Member
  • A Wing and A Prayer Cat Rescue, Volunteer
  • American Heart Association, LI chapter, Past Board Member
  • March of Dimes, Past Board Member

Articles & Presentations

  • Marcum Annual Year End Seminar 2018
  • Newsday Tax Panel, 2012
  • Daily News Tax Panel, 2011
  • Year-End Tax Update, NYSSCPA Nassau Chapter, 2009-2014

Industry Focus

Food & Beverage
Closely-Held Businesses
SEC Reporting Entities


Certified Financial Planner
College for Financial Planning

Master of Science, Taxation
C.W. Post Campus Long Island University

Bachelor of Science, Accounting
Hofstra University

Awards & Recognition

Women in Accounting, CRAINS New York, 2020
Ones to Watch in Accounting, Long Island Business News, 2020
Long Island Power Women In Business, Queens Courier, 2015
Top 50 Most Influential Women in Business, Long Island Business News, 2011 & 2013
Who’s Who in Women in Professional Services, Long Island Business News, 2010
Distinguished Service Award, NYSSCPA, 2009