Grassi

Overview

Grassi is an advisory, tax, and accounting firm providing industry-specific financial and consulting services across multiple sectors [2]. Operating as Grassi Advisory Group, Inc. and Grassi & Co. Certified Public Accountants, PC in an alternative practice structure [3], the firm maintains its headquarters in New York City at 360 Madison Avenue [7]. Grassi ranks as the number 52 largest accounting firm in the nation according to INSIDE Public Accounting [4] and has been a Top 10 leader in the Mid-Atlantic region for the third consecutive year on Accounting Today's Top 100 Firms list [6]. The firm organizes its practice around twelve industries including architecture and engineering, automotive, cannabis, construction, energy and utilities, financial services, franchise, healthcare, manufacturing and distribution, nonprofit, real estate, and sports and entertainment [10]. Grassi maintains offices across the Northeast, with additional locations in Denver, Colorado; Palm Beach, Florida; and Rome, Italy [8].

The company's own site places it in New York: Text states 'Strengthens NYC Presence' in a recent integration announcement, and references 'Locations' page suggesting NYC office; multiple. [1]

Grassi lists its New York City office at 360 Madison Avenue, 7th Floor, New York, NY 10017, phone 212.661.6166. [7]

Growth & traction

Grassi states it is the #52 largest accounting firm in the nation as ranked by INSIDE Public Accounting and #15 among the 25 best US accounting firms to work for by Vault.com. [4]

Grassi reported an 84% Net Promoter Score, more than double the industry average of 38%, with 87.3% of clients giving top satisfaction scores of 9 or 10 out of 10 versus an industry average of 48%. [5]

Grassi says its rise in national and regional rankings reflects more than four decades of sustained, organic growth, and that it has been a Top 10 leader in the Mid-Atlantic region for the third consecutive year on Accounting Today's Top 100 Firms list. [6]

Grassi lists offices in New York City, Jericho, White Plains and Ronkonkoma NY, Park Ridge NJ, Glastonbury CT, Chelmsford and Needham MA, Denver CO, Palm Beach FL and Rome, Italy. [8]

Partnerships

Grassi announced in August 2026 that Hoffman Mulligan joined the firm, an integration it said strengthens its NYC presence and tax practice for high-net-worth individuals and closely held businesses. [9]