Centenarians, or people aged 100 or older, are both rare and distinct from the rest of the older population. This report provides an updated portrait of the centenarian population based on age, sex, race, Hispanic origin, and living arrangements information collected during the 2010 Census. It also describes the geographic distribution of this population. The characteristic profile and geographic distribution of centenarians are compared with those of other age groups in the older population to illustrate how centenarians are distinct. Although some comparisons over time are included in this report, these are limited due to variations in data quality across censuses.

Any study of the centenarian population must take into account data quality issues, since they have in the past, and continue to be, obstacles to obtaining a clear picture of this population. Examples of issues affecting centenarian data include deliberate age misreporting by the respondent (e.g., age exaggeration), form or question design problems, and misallocation of extreme ages during data processing. In addition, the relatively small number of people in a population, as is the case with centenarians, can cause data to be particularly sensitive to these data issues. More information describing centenarian data quality is included at the end of this report.