Whether serving clients or fulfilling the duties of an arbitrator, Marrow's primary concerns are loyalty to the law, attention to detail, cost efficiency and timely resolution of the matters before him. His goal is to provide innovative and practical guidance for clients. His practice emphasizes the drafting and negotiating of corporate agreements involving shareholders and corporate management, financing for business operations, real estate sales and financing, distribution and licensing agreements and employment agreements. His clientele includes small and medium size manufactures of various products, metal extruders, and service providers in medical instruments and technology, advertising agencies, advertising production companies, self-storage developers and self-storage facility operators, commercial real estate developers and restaurants. He has served on numerous boards including the National Board of Governors, Self Storage Association; Board of Governors, graduate faculty of the New School for Social Research; Board of Ethics, Town of New Castle, New York; and the Westchester County Airport Advisory Board.

Marrow is listed on the roster of commercial arbitrators of many of the leading arbitration associations in the United States and abroad and is registered as an arbitrator with the United States Council for International Business (USCIB) of the International Chamber of Commerce (ICC). He has served as an arbitrator hearing cases involving business dissolution, consumer contracts, construction contracts, computer technology, insurance contracts, credit and loan agreements and securities. He is as well a Fellow, The Charter Institute of Arbitrators and a member of The Institute’s Assessment and Examinations Board.

Since 1999, Marrow has served as an adjunct member of the Regents Review Committee, an administrative law appellate panel that primarily hears appeals resulting from professional misconduct decisions by state boards for the professional groups licensed and regulated by the New York State Department of Education. He is also a member of the State of New York Grievance Committee for the Ninth Judicial District.