The Deep Life community of the Deep Carbon Observatory (DCO) is an international collaboration of researchers who have come together to identify and quantify interactions between deep life and deep Earth carbon, to transform our understanding of the processes that define the diversity and distribution of deep life, and to determine the environmental limits of deep life. This grant provides two years of support to the Deep Life community as it continues its research agenda. Over the next two years the community plans to launch five major field expeditions; conduct genomic?based studies of the diversity and function of deep life; measure and estimate presently unknown quantities like the magnitude of deep Earth biomass and the number of deep Earth endospores; and explore the molecular basis of microbial adaptation to extreme deep subsurface conditions. In addition, Deep Life community scientists will contribute to a DCO-wide modeling and visualization initiative and strengthen the field through the coordination of workshops, community meetings, and fellowships.