The National Academies of Sciences, Engineering, and Medicine convened a workshop on February 3, 2020 to explore strategies for incorporating new technologies, planning and operating strategies, business models, and architectures in the U.S. electric power system. Speakers and participants from industry, government, and academia discussed available models for long-term transmission and distribution planning, as well as the broader context of how these models are used and future opportunities and needs. This publication summarizes the presentations and discussions from the workshop.