It was with great sadness that Dr. Tristram Smith passed away in August 2018. There are many people in the field who contribute with great abundance to the published, scientific literature related to autism treatment. Many others in the field are staunch advocates for science-based treatment and best practices. Still others are generous with their time and talent while working in small, detailed, but incredibly impactful ways. Dr. Smith was all of those people. It is hard to imagine that one man can accomplish all that he has with respect to conducting and publishing decades of research, supporting an array of nonprofit organizations, mentoring young professionals, and sharing his knowledge and expertise with even the most seasoned. His contributions have been nothing short of transformational, his impact far reaching, and the tremendous gap his untimely death leaves the autism community is palpable. The panelists will share their view of Dr. Smith’s contributions and legacy, as well as some lessons learned.