Greg brings a rare combination of legal, tax, and accounting expertise to the representation of successful entrepreneurs and private clients. As a founding partner of Duggan Bertsch, Greg's practice is built around a single guiding principle: that business owners and high-net-worth individuals deserve integrated counsel that connects their corporate, tax, and estate planning strategies into one coherent, forward-looking plan.

At the center of Greg's practice is his role as co-leader of the firm's Family Office practice. Greg has spent decades designing and implementing family office structures for clients whose wealth, business interests, and multigenerational goals demand more than conventional legal advice. Whether establishing a single-family office, structuring a virtual family office, or advising an existing family enterprise on governance and succession, Greg brings both the technical depth and the strategic perspective to build structures that are tax-efficient, legally flexible, and built to endure across generations.

Greg advises clients across the full lifecycle of private wealth — from structuring and growing a business, to navigating complex federal and international tax obligations, to designing estate plans that protect and transfer wealth to the next generation. This includes guiding clients through significant corporate transactions, including mergers and acquisitions, business sales, and financing transactions, where the interplay between deal structure, tax consequences, and long-term estate planning can have lasting implications for both the business and the family behind it. His ability to work fluidly across corporate, tax, and estate disciplines means clients don't need to coordinate between siloed advisors. Greg serves as a trusted, single-source counselor who understands how decisions in one area affects the others — a perspective that is especially critical for the complex, interconnected needs of entrepreneurial families.

His experience includes sophisticated income and estate tax planning, asset protection strategies, and international tax planning for multinational businesses and their owners. Prior to founding Duggan Bertsch, Greg was a partner at a mid-sized Chicago law firm serving Family Office clients, and before that a Tax Manager in the International Tax Department of KPMG, where he focused on export subsidy programs, and cross-border tax issues for large multinational corporations.

Greg earned his Bachelor of Science in Accounting from Loyola University Chicago and his Juris Doctorate from DePaul University College of Law. He is a Certified Public Accountant.

He lectures nationally on topics including family office structures, advanced estate planning, asset protection, offshore tax compliance, and integrated domestic and international planning strategies