Since its inception at the turn of the 20th century, the Census Bureau has pioneered cutting edge methods and technologies to meet the vast and increasingly complex challenge of counting everyone in the United States. Civil rights organizations often work with the Census Bureau to ensure that innovations advance the accuracy and fairness of the decennial census. This brief focuses on one of the most significant areas of innovation over the past century: the use of “administrative data” (AD). AD are typically collected by government agencies and private-sector organizations while administering a program or service. For example, the U.S. Postal Services collects address information while delivering mail, creating an address dataset. This brief provides a definition of AD and a summary of how AD were used in the 2020 Census. The brief also introduces some key equity considerations regarding AD usage and offers potential next steps for civil rights groups.