Mark is a U.S. Attorney at Law, Barrister and Solicitor, a U.S. Certified Public Accountant and a Canadian Chartered Professional Accountant. His practice specializes in cross border legal and tax issues facing individuals primarily in the sports, music, and entertainment industry and businesses in all industries expanding into the U.S., incorporating companies and other entities in the U.S., and consulting and compliance for individuals moving to the United States and U. S. citizens who live in Canada.

He represents clients in immigration petitions, naturalizations and renunciations and other legal matters including U.S. corporate, employment, and tax litigation. He also has specific expertise in the U.S. estate, gift, generation skipping and trust taxation and assists clients and their accountants, lawyers, and financial planners with cross border planning and compliance. He has taught both full and part time university undergraduate and graduate programs, and conducts continuing education programs for CPA Ontario and other organizations.