County FIPS codes

By the CountyFinder editorial deskData as of November 1, 20268 primary sources

FIPS codes are how government datasets, mapping tools and spreadsheets agree on which county a row is about, without fighting over spelling (St. Louis or Saint Louis?) or the 31 county-level areas named Washington. If you are joining two datasets, filling in a federal form or building a map, this page explains how the code works, lists every state code, covers the changes that break old files, and gives you the full list.

What a FIPS code is

FIPS stands for Federal Information Processing Standards, a series of standards the federal government published for data processing. One of them, FIPS 6-4, defined numeric codes for counties and county equivalents ^[3]. The county code is the number most people mean when they say "FIPS code": it is printed in Census tables, used as the join key in mapping software and asked for on some federal and insurance forms.

The point of the code is that it does not depend on spelling. County names repeat across states and are written in different ways, but a FIPS code names one county and only one.

How the 5 digits are built

The first two digits are the state code and the last three are the county code within that state ^[1]. Harris County, Texas is 48201: 48 is Texas and 201 is Harris. Because the state prefix is part of it, the 5-digit code is unique in the whole country, while the 3-digit county part is not: county 001 exists in 48 different states ^[2].

The Census Bureau's county file stores the two parts in fields named STATEFP and COUNTYFP and the joined 5-digit code as GEOID. The same file also has COUNTYNS, an 8-digit ANSI feature code that is a different number (for Harris County, 01383886), and GEOIDFQ, a longer form with a summary-level prefix (0500000US48201) ^[4]. When a dataset says "county FIPS", it means the 5-digit GEOID.

State FIPS codes

State codes are two digits. They follow the alphabetical order of state names, with DC sorted as "District of Columbia". They run from 01 to 56, but 5 numbers in that range are not used by any state: 03, 07, 14, 43, 52 ^[2][1]. So a loop from 1 to 51 misses states.

Counts are counties and county equivalents in the 2024 file ^[2]. Puerto Rico and the island areas have their own codes in Census files but are not part of this list.

How county codes are numbered

Within a state, county codes often follow a simple pattern: odd numbers in alphabetical order of county name. In 40 of the 51 states and DC every county code is odd, and in 21 the codes also still run in strict alphabetical order ^[2]. Elsewhere renamed and newer counties break the pattern: Oglala Lakota County, renamed in 2015, got the even code 46102 ^[5], which sits between Moody County and Pennington County ^[2].

Two states use blocks of their own. Virginia's 38 independent cities, which are not part of any county, are numbered from 51510 to 51840, after all of the state's counties ^[2]. Connecticut's nine planning regions use 09110 to 09190, in steps of ten (see below).

Codes that changed

FIPS codes are stable but not permanent. When a county is renamed, split or merged, it can get a new code, and old files keep the old one. The Census Bureau lists these changes ^[5][6]. Every code change on its lists since 2010 (renames that kept the old code, such as LaSalle Parish, are left out):

Sources: Census Bureau county change lists and the Connecticut crosswalk ^[5][6][7]. The new codes are all in the 2024 file and the old ones are not ^[2].

Connecticut's planning regions

Connecticut is the change most likely to trip you up, because it touches every row for the state. Current Census files use nine planning regions, coded 09110 to 09190 (Capitol Planning Region, Greater Bridgeport Planning Region, Lower Connecticut River Valley Planning Region, Naugatuck Valley Planning Region, Northeastern Connecticut Planning Region, Northwest Hills Planning Region, South Central Connecticut Planning Region, Southeastern Connecticut Planning Region, Western Connecticut Planning Region), instead of the 8 old counties, coded 09001 to 09015 ^[6][2][7]. A dataset built before the switch will not join to a current one by code, and there is no one-to-one match: the regions are groups of towns, and 7 of the 8 old counties have towns in more than one region ^[7].

The Census Bureau publishes a town-level crosswalk for this ^[7]. Our Connecticut page lists the nine regions.

Common pitfalls

• Lost leading zeros. Spreadsheets turn 06037 (Los Angeles County) into 6037 and 01001 into 1001. Format the column as text before pasting, or set the column type to text when you import the CSV.
• The county part without the state. County 001 is in 48 states ^[2]. Always keep all five digits.
• Old codes in old files. Check for 46113, 02270, 02261, 51515 and Connecticut's old county codes before joining an older dataset to a current one ^[5][6].
• Mixing up ANSI feature codes. The 8-digit COUNTYNS is not the FIPS code ^[4].
• ZIP code to FIPS. A ZIP code can cross county lines, so a ZIP-to-FIPS table has to pick one county or list several. Read ZIP code vs ZCTA before you rely on one.

How to find the FIPS code for an address

For a single place, the coordinates lookup and the county finder show the county's FIPS code with the result; the check runs in your browser and your location is never sent anywhere. For a list of codes, each state page has a sortable table with every county's FIPS code, and the CSV below has all of them.

Download the CSV

One row per county or county equivalent: 5-digit FIPS code, state code, county code, state, county name, type (county, parish, borough and so on), county seat and ACS 2019-2023 population ^[2][8]. Codes are quoted text so leading zeros survive. The data is public domain (Census) and CC0 (Wikidata county seats); reuse it freely. A link back is appreciated.

Download all 3,144 county FIPS codes (CSV)

Texas only? The Texas county FIPS list has all 254 on one page.

Honest limits

This list follows the Census Bureau's 2024 county file ^[2]. County seats come from Wikidata and can lag a local change; the county's own website is authoritative. Codes for Puerto Rico and the island areas are not included. For official work, check the current Census code list ^[1].

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