This dataset contains the concentration and quality assurance results for 34 per- and polyfluoroalkyl substances (PFAS). 409 residential and commercial tapwater samples were collected once between May 2021 and May 2022, in the contiguous U.S., Alaska, Hawaii, Puerto Rico, and U.S. Virgin Islands. Of these samples 252 were from publicly supplied tapwater locations, and 155 were sourced from private wells, springs or catchment vessels. Additionally, three surface-water samples were collected in New Hampshire (as denoted with a site code suffix of '_SW' in Table 2a). An additional 85 samples were collected at 3 locations (privately sourced tapwater samples in New Jersey (30) and South Carolina (20), and a publicly supplied source in New Jersey (35)) between September 27, 2021 and December 20, 2021 to evaluate PFAS concentrations over time. Individual homeowner kits were shipped with supplies and protocols so the homeowner could collect and return the samples for analysis. Thirty-six quality-assurance field-blank samples were also collected. Quality-assurance matrix spike and surrogate percent recovery results are also presented. Samples were analyzed at the U.S. Geological Survey, National Water Quality Laboratory in Denver, Colorado. For privacy purposes, all sample locations are anonymized.