Abstract This application is a request for funds to support the 3rd annual Marmoset Bioscience Symposium (MBS) to be held November 11, two days before the start of the 2021 Society for Neuroscience (SFN) meeting in Chicago, IL. This meeting will be registered as an SFN satellite symposium. The common marmoset (Callithrix jacchus) has experienced unprecedented growth in research across the United States and is rapidly emerging as a likely keystone biomedical model system in the next chapter of scientific discovery. The major goal of the meeting is part of a multiple-pronged approach to establish a U.S.-based consortium aimed at highlighting cutting-edge research in marmosets and promoting marmosets as a key model system. This meeting will provide a networking forum for both established investigators and junior scientists from diverse backgrounds to interact and communicate their research findings. Critical to the success of the marmoset model is fostering the development of junior scientists in the field. This meeting is also aimed at attracting investigators who are currently not using marmosets in their research. The principal objectives of the MBS include: (1) to communicate and disseminate new findings from using marmosets as a model organism in diverse fields and development of new genetic, viral, and analytic tools that will advance research in marmosets; (2) to provide an open forum for discussion of new hypotheses and approaches and discrepancies in the literature and to facilitate the exchange of reagents such as antibodies, protocols, and viral toolbox; (3) to increase interactions and collaborations between basic scientists and translational and clinical groups interested in modeling human disease in the marmoset and (4) to provide an atmosphere in which researchers wishing to use marmosets in their research may interact directly with established investigators. These MBSs are highly relevant to the programmatic mission of multiple NIH ICs. The meetings consist of a Keynote Lecture, Young Investigator talks, invited talks from trainees and young investigators that are selected from submitted abstracts, and poster sessions. These meetings offer a unique combination of features, including (1) breadth of research, (2) cutting-edge questions and technologies, (3) mingling of investigators from all ranks and diverse sub-fields and locales, and (4) intimate size and extended discussion time, allowing for sustained interactions. Three tentative themes are planned: (1) Social behavior, physiology, and neural circuits, (2) Aging and neurodegenerative disease, and (3) Genetic, viral, and analytic tools developed for marmoset research. Finally, participation by women and those from underrepresented groups will be emphasized. Half of the oral presentations will be from these groups and half of the travel awards will be given to women. The leadership of the MBS itself is ~43% female.