disposal, and wastewater systems; energy infrastructure (excluding nuclear); and transportation systems (excluding pavements). Both disciplinary and convergent research that can address the challenges of physical civil infrastructure to be resilient and sustainable over its service lifetime are of particular interest. Broader impacts of ECI research include fostering community welfare for an equitable and prosperous nation and promoting environmentally friendly, circular economy policies. The ECI program supports research that advances knowledge on the behavior of physical civil infrastructure subjected to and interacting with the natural environment during construction; under service and long-term conditions, including increased demands due to climate change adaptation and other emerging stressors; and under conditions caused by single or multiple extreme hazard events (extreme weather, windstorms, earthquakes, tsunamis, storm surges, landslides, and fire, including wildland-urban interface fire). The ECI program also supports research on geomaterials and infrastructure materials utilized in load-bearing systems as well as in non-structural systems. Of particular interest is experimental and analytical/computational research to advance the fundamental understanding of coupled multi-physics, multi-scale (spatial and temporal), multi-functional behavior of these materials and their intended use in civil infrastructure. The ECI program supports research on civil infrastructure that contributes to the National Science Foundation’s role in the National Earthquake Hazards Reduction Program (NEHRP) and the National Windstorm Impact Reduction Program (NWIRP). Principal Investigators are encouraged to leverage NSF’s investments in the Natural Hazards Engineering Research Infrastructure (NHERI) experimental, computational modeling and simulation, and data resources (https://www.designsafe-ci.org/) in their research to accelerate advances needed for reducing the impacts of natural hazards on civil infrastructure. The NHERI Science Plan (https://www.designsafe-ci.org/facilities/nco/science-plan/) offers a range of research topics that could benefit from the use of NHERI resources and are relevant to the ECI program. The ECI program does not support research that addresses natural resource exploration or recovery, investigates blasts and explosions, develops sensor and measurement technologies, or focuses on hazard characterization. The ECI program only supports fundamental research topics for civil infrastructure with a strong grounding in theory. Topics which fall within the mission for research and/or development of other federal and state agencies are appropriate for the ECI program only when addressing fundamental scientific questions. Research on natural hazard characterization is supported through programs in the NSF Directorate for Geosciences. Proposers are actively encouraged to email a one-page project summary to the ECI Program Officers before submitting a full proposal for guidance on whether the proposed research topic falls within the scope of the ECI program; this guidance especially should be requested for multi-disciplinary research proposals, proposals for which research and/or development on the subject civil infrastructure(s) are also supported by other federal and state agencies, and proposals that consider civil infrastructure not listed above.