Mark A. Hertlein

Mark Hertlein has more than 35 years of experience in public accounting, specializing in tax compliance, consulting and strategic tax planning. He advises corporations, partnerships, multistate businesses, trusts and estates, not-for-profit organizations and high-net-worth individuals. His practice includes serving closely held businesses, tax-exempt organizations and private clients with complex tax and financial planning needs.

Mark helps clients develop tax-efficient strategies to preserve wealth, support long-term objectives and address complex tax matters. His experience includes income tax planning, estate and trust taxation and representation in federal and state tax controversy and resolution matters.

Prior to joining PKF O’Connor Davies, Mark spent several years at a Big Four accounting firm and more than a decade advising tax-exempt organizations. He has worked with public charities, private foundations, educational institutions, healthcare organizations and other not-for-profit entities. His experience includes tax compliance, organizational structuring, unrelated business income tax (UBIT) planning and navigating the complex regulatory requirements affecting tax-exempt organizations.

In addition to his client service responsibilities, Mark is dedicated to mentoring and developing professionals at all levels. He provides guidance on complex tax matters, fosters collaboration and supports professional growth. Through his leadership and technical knowledge, he helps team members strengthen their skills, address challenges and support the delivery of client service.