Andy Herz operated as a broad-based commercial real estate lawyer advising corporate clients on acquisition, development, and leasing transactions. Specifically, past editions of Chambers USA have stated that ‘the "terrific," "excellent" and "very capable" Mr. Herz “has vast knowledge of the real estate world, and he provides highly pragmatic solutions to issues.” Contemporaries have stated that they referred leasing matters to him "without a shadow of a doubt."’ Clients have stated that he is "an incredible leasing lawyer, probably the best in the city in terms of leasing." Mr. Herz is a member of the American College of Real Estate Lawyers. He was recognized as a leading lawyer in Chambers USA as a key member of the firm’s highly rated real estate department.

Mr. Herz’s clients included major real estate owners and developers, hedge funds, technology providers, hospitals, professional service companies, charitable institutions, and other law firms. He has been an adjunct professor at both Vanderbilt Law School and Brooklyn Law School where he taught intensive commercial real estate law courses. For fourteen years, Mr. Herz was a member of the Advisory Board and presenter at Georgetown University's Advanced Commercial Leasing Institute.

Mr. Herz received the 2016 New York Bar Association’s Real Property Law Section Professionalism Award for his “exceptional contributions of time and talent to New York real estate lawyers.” The award identifies a person “possessing an outstanding level of competence, legal ability and achievement; a continuing civility and appreciation for others in his/her practice; a person who has engaged in mentoring of younger attorneys, and who has been involved in Bar activities both on a state and local level.” Based substantially on his background with workouts, financing, and real estate operation, he has four times been named a receiver in commercial property foreclosures. Earlier in his career, Mr. Herz was the General Counsel of the New York State Mortgage Loan Enforcement and Administration Corporation, the workout arm of New York’s Urban Development Corporation, which handled its defaulted $1.2 billion mortgage portfolio.

Mr. Herz held leadership positions in numerous professional organizations, having served as chair of the Leasing Committee of the American College of Real Estate Lawyers; co-chair of the Office Leasing Committee and the Real Estate Asset Management Committee of the American Bar Association; and chair of the New York State Bar Association's Commercial Leasing Committee. He has also been designated as a Fellow of the American Bar Foundation and a member of the New York City Committee of the Regional Plan Association. Mr. Herz has participated in seminars on workouts, commercial leasing, loan restructurings, and mortgage financing for numerous industry groups, including New York University Real Estate Institute, the Real Estate Board of New York, the Practising Law Institute, the International Council of Shopping Centers, the New York Law Journal, The National Association of Corporate Real Estate Executives, and the Harvard Business School Real Estate Club. He served as a contributing editor to the New York Bar Association's text, Commercial Leasing, published in 2017.

Mr. Herz was a frequent guest on "Wake Up With Whoopi" talking about real estate law issues with Whoopi Goldberg. He serves as a member of the Board of Directors of White Plains Hospital and was previously a Board Member of New Beginnings, a subsidiary of Hudson Link for Higher Education in Prison. He has also been designated as an Honorary Director of Planned Parenthood of Greater New York.