According to the Census Bureau, "GEOIDs are numeric codes that uniquely identify all administrative/legal and statistical geographic areas for which the Census Bureau tabulates data."
At a practical level, GeoIDs (also called FIPS Codes) are different combinations of those Census identifiers. Depending on the data you're working with, you might need a different length of GeoID.
GeoIDs, or FIPS codes, can be up to 40 digits. The more digits there are, the more granular of a measurement it is.
Geocodio returns FIPS codes, and from those FIPS codes, you can create the GeoID you need based on the required number of digits.
GeoIDs are built based on a combination of Census FIPS codes, which are unique identifiers for differnet levels of geographic data. The largest geographic area covered by a FIPS code is the State, and the smallest is the Block. Here's the order of FIPS codes, in declining order of size:
Geocodio will return these FIPS codes levels to you, and then you can build the GeoID you need.
Let's use 1600 Pennsylvania Avenue, Washington DC as an example:
| If you have/need a GeoID of this length... | ...it translates to this combination of FIPS codes | Example GeoID | Geocodio Results to Use |
|---|---|---|---|
| 2 digit GeoID | State | 11 | State FIPS |
| 5 digit GeoID | State + County | 11001 | County FIPS (i.e. concatenated State + County) |
| 11 digit GeoID | State + County + Tract | 11001006802 | combine County FIPS + Tract Code; pre-concatenated for spreadsheet uploads as "Full FIPS (tract)" |
| 12 digit GeoID | State + County + Tract + Block Group | 110010068022 | combine County FIPS + Tract Code + Block Group |
| 15 digit GeoID | State + County + Tract + Block | 110010068022012 | combine County FIPS + Tract Code + Block Code; pre-concatenated for spreadsheet uploads as "Full FIPS (block)" |
Geocodio can also help you add historical (past-year) Census FIPS codes, blocks, and tracts to addresses or coordinates. Data is available for the 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021 and 2022 Census years.
Our Census data append includes:
More of a visual learner? Watch a video
The 11-digit GeoID is a combination of the State, County, and Tract FIPS codes. For example, IRS Form I8911, Alternative Fuel Vehicle Refueling Property Credit requires an 11-digit GeoID. This is returned by Geocodio in the component pieces as well as pre-concatenated as "Full FIPS (tract)".
The 12-digit GeoID is a combination of the State, County, Tract, and Block Group FIPS codes. For example, schools use the 12-digit GeoID to determine eligibility for the USDA's Child and Adult Care Food Program (CACFP) and the Summer Food Service Program (SFSP).
The 15-digit GeoID is a combination of the State, County, Tract, and Block FIPS codes. For example, FCC Form 477, Fixed Broadband Deployment requires a 15-digit GeoID. This is returned by Geocodio in the component pieces as well as pre-concatenated as "Full FIPS (block)".