Grassi adds Hoffman Mulligan | Accounting Today

Grassi, a Top 75 Firm based in New York, has added Hoffman Mulligan, strengthening its high-net-worth and tax practice capabilities and expanding its presence in New York City, effective Aug. 1.

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As part of the deal, partners Don Hoffman and Janet Mulligan are joining Grassi along with 20 professionals at Grassi’s headquarters at 360 Madison Avenue (where Accounting Today is coincidentally also located). Hoffman and Mulligan bring over eight decades of combined experience advising individuals, families and business owners on complex tax matters. 

The combination bolsters Grassi’s ability to serve high-net-worth individuals and closely held businesses with specialized tax advisory and planning solutions, further strengthening its position in a key market.

“Hoffman Mulligan brings a strong reputation for client service and deep technical expertise that closely aligns with our approach,” said Grassi founder and CEO Louis C. Grassi in a statement Thursday. “This is a strategic step to further expand our capabilities and presence in New York City. As an independent, employee-owned firm, we remain focused on building long-term relationships and delivering thoughtful, forward-looking advice.”

Last November, Grassi acquired OnePoint Franchise Accounting, based in Denver. In January 2025, Grassi added Anstiss & Co., an accounting, tax and consulting firm based in Chelmsford, Massachusetts. In 2023, Grassi set up an employee stock ownership plan and established an alternative practice structure, splitting the firm into two entities: Grassi Advisory Group, which performs advisory and tax services, and Grassi CPAs, which handles audit and attest work. Grassi Franchise Services is part of Grassi Advisory Services and has provided advisory, tax and accounting services to leading U.S. franchises for over 25 years. 

In 2021, Grassi acquired Gramkow, Carnevale, Seifert & Co. in Oradell, New Jersey, and S&Z Fund Services in New York. In 2020, it added Levine, Caufield, Martin & Goldberg in Needham, Massachusetts.

Together, they have established a reputation for personalized service, continuity, and proactive planning that aligns closely with Grassi’s client-focused approach.

This integration reflects Grassi’s ongoing commitment to organic growth and strategic expansion by investing in talent while maintaining its independence and high-touch client service model.