
The Real Estate Roundtable mourns the loss of Donald B. Susswein, a longtime member, brilliant tax expert, and dedicated mentor who passed away April 2.
- Don served as a partner in RSM‘s Washington National Tax office, where he helped build the firm’s Passthrough Tax Consulting Capability and guided many colleagues into leadership roles — a source of immense pride for him.
- His distinguished career also included roles at two Big 4 firms, a partner at Thacher Proffitt and Wood, a Wall Street law firm, the U.S. Senate Finance Committee, and the Department of Justice.
- Throughout his years with RER, Don was a driving force behind our Tax Policy Advisory Committee (TPAC), offering his expertise through monthly calls, studies, panels, and helping craft amicus briefs that helped advance our tax policy priorities. Don was a key architect of the partnership audit reform legislation enacted in 2015 and a major contributor to the development of the pass-through business income deduction enacted in 2017. His work revolutionized the way the tax community thinks about like-kind exchanges (as part of a broader continuum of deferrals available for business restructurings). From FIRPTA, to cancellation of indebtedness, to unrealized gains, Don tackled many other difficult issues through The Roundtable.

- Roundtable President and CEO Jeffrey DeBoer said, “Don was a genius — a brilliant problem solver and a loyal, supportive friend. His clever comments and contagious smile brought levity and clarity to even the most complex policy debates. I’ve known Don since the mid-1980s, when he was already recognized on Capitol Hill as one of the true tax policy sharpies. If you wanted to discuss tax legislation with Don you had to bring your “A” game, even so his game was always “A-plus”. We will deeply miss his voice at The Roundtable, especially in our tax policy deliberations.”
- Roundtable Senior Vice President and Counsel Ryan McCormick said, “Don was a mentor, coauthor, and friend who brought tremendous wit and wisdom to every complicated tax issue we tackled. Don delighted in the opportunity to solve the unsolvable, and he often succeeded. From partnership audit reform to section 199A to like-kind exchanges, Don brought ideas and insights that challenged traditional thinking, transformed debates, and led Congress to enact better laws. Don made many selfless contributions to The Roundtable and our industry, but it is his kindness and steadfast friendship that will be most missed.”
A funeral service is scheduled for Tuesday, April 8 at the Garden of Remembrance Chapel in Clarksburg, MD with a live stream available. In lieu of flowers, a donation in his memory can be made to the Special Olympics, Young Artists of America, and Donate Life DC. (See Obituary for details)