FIPS Code
Definition
Federal Information Processing Standards codes are numeric identifiers assigned to geographic entities (states, counties, cities) by the National Institute of Standards and Technology. State FIPS codes are 2 digits; county codes are 5 digits (state + county).
Why It Matters
FIPS codes are the standard way to uniquely identify geographic areas in government data. They enable linking data across different federal agencies and datasets.
How It's Measured
Assigned by NIST. State codes range from 01 (Alabama) to 56 (Wyoming). County codes append a 3-digit suffix to the state code.
Related Terms
Related Glossary Terms
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Frequently Asked Questions
Federal Information Processing Standards codes are numeric identifiers assigned to geographic entities (states, counties, cities) by the National Institute of Standards and Technology. State FIPS codes are 2 digits; county codes are 5 digits (state + county).
FIPS codes are the standard way to uniquely identify geographic areas in government data. They enable linking data across different federal agencies and datasets.
Assigned by NIST. State codes range from 01 (Alabama) to 56 (Wyoming). County codes append a 3-digit suffix to the state code.
FIPS Code is one of the U.S. population demographics concepts that recurs across this site. The definition above is the technical answer; the paragraphs below add the practical context for how the concept connects to the the U.S. Census Bureau ACS and decennial files data behind every per-entity page on the site.
In the the U.S. Census Bureau ACS and decennial files data, this concept shapes one or more of the fields that drive the per-entity grades and rankings on this site. The methodology page describes which fields feed into which output; this glossary entry documents the underlying term.
Source: U.S. Census Bureau ACS, 2026.