Progress and Expansion of the National Wastewater Surveillance System, United States, 2020-2024.

Wastewater surveillance in the United States has evolved from an emergency response initiative into a valuable component of public health infrastructure. During its first 4 years, the Centers for Disease Control and Prevention's National Wastewater Surveillance System (NWSS) expanded its national testing coverage, suite of pathogen targets, analytics capabilities, data visualizations, and laboratory methods. Collaborations across public, private, and academic sectors continue to drive progress toward standardization of practices, interpretation of wastewater signals, and translation of wastewater surveillance into public health action. This article describes the evolution of NWSS from late 2020 through 2024, highlighting its integration into public health practice and its demonstrated adaptability and scalability as a surveillance system supporting timely, data-driven decision-making to address community-level public health threats.