The Established Program to Stimulate Competitive Research (EPSCoR) fulfills the mandate of the National Science Foundation (NSF) to promote scientific progress nationwide. Through this program, NSF facilitates the establishment of partnerships among academic institutions, government, industry, and non-profit sectors that are designed to promote sustainable improvements in the research infrastructure, Research and Development (R) capacity, and R competitiveness of EPSCoR-eligible jurisdictions (i.e., states, territories, and commonwealths). The E-CORE RII program supports jurisdictions in building capacity in one or more targeted research infrastructure cores that underlie the jurisdiction's research ecosystem. Based on the evidence-based and self-identified need of the jurisdiction, capacity building supported by E-CORE RII may include (but is not limited to) development, enhancement, and/or sustainability of: jurisdiction-wide research administration; research facilities; higher education pathways; STEM education (K-16) pathways; broadening participation; workforce development; national and global partnerships; community engagement and outreach; economic development and use-inspired research; and/or early career research trainee pathways. E-CORE RII projects must be designed to support the sustainability of the infrastructure core(s) beyond the award period.In E-CORE RIIs support of one or more research infrastructure cores in an EPSCoR-eligible jurisdiction, the program will also support the development and growth of new jurisdictional networks, and the leveraging of existing jurisdictional networks, that can drive demonstrable and sustainable impact to advance the jurisdiction-wide research ecosystem. Through the fostering of STEM research ecosystems and research capacity pathways across institution types and sectors in a jurisdiction, E-CORE RII aims to support jurisdiction-wide research infrastructure cores based on jurisdictional variability. A jurisdictions science, technology, engineering, and mathematics (STEM) research ecosystem encompasses all new and ongoing interactions among its research environment, researchers, stakeholders, and STEM research activities to improve knowledge, or contribute to end-use or societal impacts in the jurisdiction.