Federal information processing standards codes (FIPS codes) are a standardized set of numeric or alphabetic codes issued by the National Institute of Standards and Technology (NIST) to ensure uniform identification of geographic entities through all federal government agencies. The entities covered include: states and statistically equivalent entities, counties and statistically equivalent entities, named populated and related location entities (such as, places and county subdivisions), and American Indian and Alaska Native areas.
The NIST maintains a Web site of FIPS codes and information. FIPS publications include:
The U.S. Census Bureau uses the codes in FIPS PUB 55-3 to identify both legal and statistical entities for county subdivisions, places, and American Indian areas/Alaska Native areas/Hawaiian home lands. FIPS PUB 55-3 includes many more entity records than those for which the Census Bureau tabulates data. The FIPS 55 codes are state-based. American Indian reservations, off-reservation trust land areas, American Indian tribal subdivisions, Oklahoma tribal statistical areas (OTSAs), state designated American Indian statistical areas (SDAISAs), and/or tribal designated statistical areas (TDSAs) in more than one state will have multiple FIPS 55 codes; that is, a different FIPS 55 code for each state portion of the single American Indian entity.