Summary File 4 (SF4) contains the sample data, which is the information compiled from the questions asked of a sample of all people and housing units.

The sample data are presented in 213 population tables (matrices) and 110 housing tables, identified with "PCT" and "HCT", respectively. Each table is iterated for 336 population groups: the total population, 132 race groups, 78 American Indian and Alaska Native tribe categories (reflecting 39 individual tribes), 39 Hispanic or Latino groups, and 86 ancestry groups.

SF 4 is released as individual files for each of the 50 states, the District of Columbia, and Puerto Rico; and for the United States. The tables (matrices) are identical for all files, but the geographic coverage differs. Data are provided down to the census tract level.