Mark Mirsky is a licensed CPA in Illinois with in-house corporate accounting experience and has worked in both large and small accounting firms. He has a Master's in Taxation from University of Illinois, Urbana-Champaign.

In 2004 Mark co-founded ROI Business Services, LLC, where he leads tax and management advisory services. With a focus on partnerships, S-corporations, C-corporations, and multi-state taxation, Mark provides assistance for business startups, the acquisition and disposition of businesses, international taxation, and real estate. Mark works with businesses and organizations across the country and around the world, including manufacturing/distribution, technology and web-based, and construction companies, as well as service firms and medical practices. He also works with individuals providing tax planning. Mark's background includes working in the international tax group at one of the largest accounting firms in the world and for two middle-market firms focusing on closely held businesses, serving as a firm-wide resource for partnership and multistate taxation