The BioWatch program, managed by the U.S. Department of Homeland Security, is designed to detect aerosolized biological attacks by continuously monitoring the air for specific biological threats using strategically placed air collectors. This federally managed, locally operated system provides early warnings of biological incidents, enabling state and local authorities to respond quickly and effectively, thereby reducing casualties and fatalities. BioWatch supports the National Biodefense Strategy and Implementation Plan (2022) by informing decision-making, enhancing preparedness, and providing post-incident support to limit the impacts of biological threats. Operating in over 30 metropolitan areas across 22 states, BioWatch protects roughly one-third of the U.S. population and extends its coverage to high-visibility special events. Its core activities include operating air samplers, collecting and analyzing air samples, assisting partners with planning and preparedness through guidance, training, and exercises, and alerting and coordinating response actions upon detection of a threat. The program’s objectives are to maintain a robust biodetection capability, engage stakeholders in preparedness and response, and establish coordination mechanisms across federal, state, local, and tribal levels to ensure rapid and effective public health responses to bioterrorist attacks. This Notice of Funding Opportunity (NOFO) is for the performance of field operations--including deploying and maintaining a fleet of air monitoring units, collecting and replacing filters from those units, and transporting filters daily to BioWatch laboratories in metropolitan areas identified below. As optional for specific metropolitan areas listed below, field operations further include laboratory operations, such as sample processing, analysis, and results reporting. Eligible recipients of this cooperative agreement are state and local government agencies, regional governmental organizations, public institutions of higher learning, and federally recognized tribal governments.