The NGEE Arctic Ecosystem Type workshop, the first of its kind, was held on October 20th and 22nd, 2020 via Zoom. The multi-lab, multi-institution organizing committee, Katrina E. Bennett (LANL), Elchin Jafarov (LANL), Daryl Yang (Brookhaven), and Dmitry Nicolsky (UAF) put together the 2-day workshop to include an overview of ecosystem types, including presentations that detailed the history of the ecosystem types in the literature, examples of how ecosystem type is being applied in the NGEE Arctic project for different science questions and model parameters (i.e. vegetation, permafrost, and snow mapping), how ecosystem types can be applied in models such as ELM and FATES models, and how remote sensing applications may be useful for ecosystem type mapping. A special presentation by NGEE Arctic guest Don McLennan was also given on the Canadian Arctic-Subarctic Biogeoclimatic Ecosystem Classification (CASBEC). Breakout sessions on both days tackled questions such as, how an Ecosystem MODEX or Modeling Unit (EMU) concept can be applied in models such as E3SM/ELM and FATES, how ecosystem types can be used for scaling, and how remote sensing tools can be applied to map EMUs. The final outcome of the workshop will be a paper on the topic area, with case studies focused on NGEE Arctic’s application of EMUs in the Arctic.