The Federal Government uses a unique two-digit numeric code to identify each State and State equivalent entity. These State codes are part of the Federal Information Processing Standards (FIPS), an official coding system developed by the National Institute of Standards and Technology (NIST, formerly the National Bureau of Standards), U.S. Department of Commerce, and maintained by the U.S. Geological Survey (USGS). These FIPS codes parallel the alphabetic sequence of State names, including the District of Columbia, followed by Puerto Rico and the Outlying Areas in alphabetical order (see Table 4-5). Gaps left in the State numbering sequence provide for the possibility that a major Outlying Area may attain statehood using its current name. In addition, the FIPS for States includes a two-letter alphabetic code, used by both the NIST and the U.S. Postal Service, which has been adopted by many other Federal agencies.
In addition to the FIPS codes for States, the Census Bureau devised and uses a system of two-digit codes to identify each State in a geographic sequence within its census division. Each of the nine census divisions encompasses a group of adjacent States; the first digit of the Census Bureau’s State code identifies the division and the second digit refers to the geographic sequence of the individual State within that division. The territories under U.S. jurisdiction are not assigned to any of the nine census divisions, and their codes have a first digit of 0 in the Census Bureau’s scheme (see Table 4-5). Chapter 6, “Statistical Groupings of States and Counties,” presents a discussion of the census regions and divisions.
Another FIPS coding scheme that the Census Bureau uses identifies the counties alphabetically within each State. The FIPS 6 publication assigns each county a three-digit numeric code, with gaps in the numbering sequence to allow for additions and revisions. The independent cities appear at the end of the county list for each appropriate State, beginning with code 510.
States, Counties, Equivalent Entities4-15
