Grassi

Grassi is a national advisory, tax, and accounting firm headquartered in Jericho, founded in 1980 by Louis C. Grassi. It has grown to more than 550 employees, with a second Long Island office in Ronkonkoma and locations in Manhattan, Westchester, New Jersey, New England, Florida, and Italy. In 2023, it became employee-owned through an employee stock ownership plan (ESOP).

Grassi serves businesses in construction, architecture and engineering, manufacturing and distribution, real estate, healthcare, nonprofit, franchise, and financial services. Its work spans audits, tax planning and compliance, CFO and business advisory, valuation, forensic accounting, and technology consulting.

The firm is regularly recognized as a top workplace, including a 2026 Long Island Top Workplaces award, and it publishes industry research such as its annual Manufacturing & Distribution Technology Survey.