What is a FIPS Code?
A FIPS code (Federal Information Processing Standards code) is a numeric identifier
assigned by the US government to uniquely identify states, counties, metropolitan areas, and other
geographic and administrative entities. If you've ever worked with a federal dataset and wondered
what 53033 or 06037 means, you've encountered a FIPS code.
Why FIPS Codes Exist
Before FIPS codes, federal agencies used incompatible naming conventions for geographic areas — "LA County," "Los Angeles County," and "Los Angeles Co." could all appear in different datasets for the same place, making data joins a nightmare. FIPS codes solved this by providing a single, stable numeric key that every federal agency agreed to use.
The standard was published by the National Institute of Standards and Technology (NIST) and is now maintained by the Census Bureau as the ANSI (American National Standards Institute) standard.
FIPS Code Structure
State FIPS Codes (2 digits)
States are assigned 2-digit codes from 01 (Alabama) through 56 (Wyoming), though not all numbers in that range are used. US territories like Puerto Rico (72) have their own codes.
County FIPS Codes (5 digits = state + county)
County FIPS codes are 5 digits: the first 2 identify the state, and the last 3 identify the county within that state. For example, 53033 = Washington state, county 033 = King County.
Types of Geographic FIPS Codes
| Code Type | Digits | Example | What It Identifies |
|---|---|---|---|
| State | 2 | 53 | Washington state |
| County | 5 | 53033 | King County, WA |
| MSA / Metro Area | 5 | 42660 | Seattle-Tacoma MSA |
| Congressional District | state+district | WA-07 | Washington's 7th CD |
| Census Tract | 11 | 53033005302 | A tract within King County |
Are FIPS Codes the Same as ZIP Codes?
No — they're completely different. ZIP codes are a postal routing system managed by the US Postal Service. FIPS codes are government administrative identifiers. They don't overlap or correspond to each other. A single ZIP code may span multiple counties (each with different FIPS codes), and a county contains hundreds of ZIP codes.
When Are FIPS Codes Changed?
FIPS codes are generally stable but do occasionally change when counties are created, dissolved, or renamed. Virginia has undergone the most changes due to its independent cities. The Census Bureau publishes an updated ANSI reference file with each decennial census and maintains changes in between.
Decoding FIPS Codes
Use FipsDecoder to instantly translate any FIPS code into its human-readable location. You can search by code or by place name.