Louis C Grassi, CPA, CFE

Louis C. Grassi, CPA, CFE is the CEO, Founder and Managing Partner of GRASSI, a national advisory, tax and accounting firm headquartered in New York. Under his leadership the firm has grown into one of the largest accounting practices in the United States, and it has been recognised with the Corporate INTL Global Awards 2026 — CPA Firm of the Year in New York, US.

GRASSI

GRASSI is a national advisory, tax and accounting services firm. Its work spans a wide spectrum of advisory services — including CFO advisory, corporate restructuring, forensic, litigation and valuation services, transaction advisory, private client services and technology consulting — alongside a full range of tax services, from planning and compliance to credits and incentives, tax controversy, state and local tax, international tax and trust and estate work. On the accounting side, the firm provides audits, reviews and compilations, client accounting and advisory services, employee-benefit-plan audits, SOC audits and public-company services.

The firm serves clients across a broad set of industries, among them architecture and engineering, construction, financial services, healthcare, manufacturing and distribution, nonprofit, real estate, and sports and entertainment. It is ranked the 52nd largest accounting firm in the nation by Inside Public Accounting and has been recognised among the top US accounting firms to work for, reflecting both its scale and its culture.

Louis C. Grassi

Louis Grassi founded the firm at the age of 24 and has led it through 45 years of change in the profession. In 2023 he transitioned the business to an employee-owned ESOP model, making it one of the largest employee-owned firms in the profession — a step that aligns the firm's ownership with the people who build its client relationships. A Certified Public Accountant and Certified Fraud Examiner, he is a graduate of Queens College, where he earned a degree in business administration in accounting, and he completed postgraduate courses in taxation before earning his CFE designation from the National Association of Certified Fraud Examiners.

His professional standing extends well beyond the firm. He is a former Chair of Moore North America and has served as an executive board officer of the New York State Society of Certified Public Accountants and as a member of the American Institute of Certified Public Accountants. He has held board positions with Flushing Financial Corp and BRT Realty, served on the advisory board of the Northwell Cancer Institute, and taught as an adjunct professor of graduate-level finance and accounting at Columbia University.

The CPA profession in New York

New York is one of the most competitive professional-services markets in the world, and CPA firms there serve a demanding clientele of businesses, investors, family offices and nonprofits. Success in this environment requires more than technical accounting proficiency; it calls for the ability to combine assurance and tax services with strategic advisory work that helps clients navigate financing, transactions, regulation and risk. GRASSI's breadth across advisory, tax and accounting positions it to meet these varied needs under one roof.

• Advisory services, including CFO advisory, restructuring and transaction advisory
• Tax planning, compliance, controversy and international tax
• Audit, assurance and client accounting services
• Industry-focused expertise across construction, healthcare, real estate and more

Scale, culture and continuity

Few leaders in the accounting profession have shaped a firm as completely as Louis Grassi has shaped GRASSI. Founding the practice as a young CPA and guiding it over four and a half decades into one of the fifty largest firms in the United States required not only technical excellence but also a sustained vision for how a professional-services business should grow and serve its clients. The 2023 transition to an employee-ownership structure is a natural expression of that vision, tying the firm's future to the people who deliver its work and reinforcing a culture in which client relationships are built to last. His extensive external roles — in professional bodies, on corporate boards, in the classroom and in the community — reflect a career devoted to the profession as a whole, and they lend added weight to the recognition of GRASSI in the 2026 awards.

Louis C. Grassi's four and a half decades of leadership, his professional credentials and his commitment to an employee-owned model have shaped GRASSI into a firm of national scale and reputation. The Corporate INTL Global Awards 2026 — CPA Firm of the Year in New York, US recognises both his personal standing in the profession and the strength of the firm he built.