The Community Infrastructure for Research in Computer and Information Science and Engineering (CIRC) program drives discovery and learning in the core disciplines of the three participating CISE divisions [Computing and Communication Foundations (CCF), Computer and Network Systems (CNS), and Information and Intelligent Systems (IIS)] of the Directorate for Computer and Information Science and Engineering (CISE) by funding the creation and enhancement of world-class research infrastructure. This research infrastructure will specifically support diverse communities of CISE researchers pursuing focused research agendas in computer and information science and engineering. This support involves developing the accompanying user services and engagement needed to attract, nurture, and grow a robust research community that is actively involved in determining directions for the infrastructure, as well as management of the infrastructure. This should lead to research infrastructure that can be sustained through community involvement and community leadership, and that will enable advances not possible with existing research infrastructure. Further, through the CIRC program, CISE seeks to ensure that researchers from a diverse range of institutions of higher education (IHEs), including minority-serving and predominantly undergraduate institutions, as well as researchers from non-profit, non-academic organizations, have access to such infrastructure. The CIRC program supports four classes of awards: Planning Community Infrastructure (Planning) awards support planning efforts to engage research communities to develop new CISE community research infrastructures. Such an infrastructure could be eventually funded through the CIRC program (Planning-C) or the NSF Mid-scale Research Infrastructure (MsRI) program (Planning-M). For the scope of Mid-scale RI proposals, see the Mid-scale RI-1 and Mid-scale RI-2 program pages. Exploratory Development (Dev) awards support activities that involve the validation of one or more unproven infrastructure designs and/or technologies, which, if validated, could enable transformative community research infrastructure in the future. Successful projects are expected to provide the technical foundations necessary to pursue subsequent CIRC (New or Grand), Mid-scale RI-1, or Mid-scale RI-2 projects. Medium Community Infrastructure (Medium) awards support the creation of new CISE community research infrastructure or the enhancement of existing CISE community research infrastructure with integrated tools, resources, user services, and research community outreach to enable innovative CISE research opportunities to advance the frontiers of the CISE core research areas. The Medium award class includes New (New) and Enhance/Sustain (ENS) awards. Grand Community Infrastructure (Grand) awards support projects involving significant efforts to develop new CISE community research infrastructure or to enhance and sustain an existing CISE community research infrastructure to enable world-class CISE research opportunities for broad-based communities of CISE researchers that extend well beyond the awardee organization(s). Each CIRC Medium or Grand award may include support for operation of the infrastructure, ensuring that the awardee organization(s) is (are) well positioned to provide a high quality of service to CISE community researchers expected to use the infrastructure to realize their research goals.