Geography
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Census Geocoder
For governments interested in the Local Update of Census Addresses Operation block count lists, they can be found on the 2020 Census LUCA webpage.
The Census Geocoder is an address look-up tool that converts your address to an approximate coordinate (latitude/longitude) and returns information about the address range that includes the address and the census geography the address is within. The geocoder is available as a web interface and as an API (Representational State Transfer - REST - web-based service).
The tool allows you to look-up a single address or batch submit up to 10,000 addresses at a time. In addition, you can find the location of an address, the latitude and longitude, using the “Find Locations Using…” option. You can also find the census geographic entities for an address using the “Find Geographies Using…” option. The “Find Geographies Using…” option returns the state, county, census tract, and block for each address. Additional geographies are available using the instructions under Documentation below.
When geocoding your address, you need to select a benchmark (time period) and select a vintage of geography. The benchmark is the time period when we created a snapshot of our data (generally done twice a year). For example, Public_AR_Census2010 is the snapshot we took of the database in 2010. Public_AR_Current is the most recent snapshot we took of our dataset. The vintage of geography is the census or survey that the data relates to. For example, Census2010_Census2010 are the address ranges from the 2010 Census at the time of the 2010 Census. You can also obtain the 2010 Census address ranges as of our most recent benchmark. The vintages you see available depends on the benchmark you selected.
Data in the Census Geocoder
The information in the geocoder comes from our MAF/TIGER database, which holds our geographic information used for censuses and surveys. The address ranges used in the geocoder are the same address ranges that can be found in the TIGER/Line Shapefiles which are derived from the Master Address File (MAF).
There are limitations to the address ranges found in our MAF/TIGER database. The address ranges are potential address ranges, not actual address ranges. Potential ranges include the full range of possible structure numbers even though the actual structures might not exist. The majority of the address ranges we have are for residential areas. There are limited address ranges available in commercial areas. Our address ranges are regularly updated with the most current information we have available to us.
Batch Geocoding Process
How to Format your Address List
Addresses should be formatted in a single line with comma delimiters. The address should consist of:
- Unique ID,
- House Number and Street Name,
- City,
- State,
- ZIP Code
- 1, 1600 Pennsylvania Ave NW, Washington, DC,
- 2, 1600 Pennsylvania Ave NW, , , 20502
- 3, 1600 Pennsylvania Ave NW, Washington, DC
- 4, 1600 Pennsylvania Ave NW, 20502
are both invalid entries.
The batch geocoder can process up to 1,000 addresses at a time. It may take several minutes to process this many addresses.
Results
The geocoder takes the address and determines the approximate location offset from the street centerline. An interpolated latitude/longitude coordinate is returned along with the address range the Census Bureau has on that stretch of road. That coordinate is then used to determine the geography that the address is within.
The results can be:
- Match/Exact
- Match/Non-Exact
- Tie
- No Match
Using the web interface "Find Locations Using" option, the results include the estimated latitude/longitude coordinate, TIGER identifier of the street, and full address range on the road segment.
Using the web interface "Find Geographies Using" option, results are returned for the State, County, Census Tract, and Block the address is located within. In addition, attributes of these pieces of geography, such as an urban/rural indicator are included.
The state, county, census tract, and block codes are returned.
Record Layouts for Output
Finding Geographies Using Option
| Column | Column Name | Column Description |
|---|---|---|
| 1 | ID | ID from original address list |
| 2 | Address1 | Address from original address list |
| 3 | Matching Result 1 | Results indicating whether or not there was a match for the address (Match, tie, no match) |
| 4 | Matching Result 2 | Results indicating if the match is exact or not (Exact, non-exact) |
| 5 | Address2 | Address the original address matches to |
| 6 | Latitude, Longitude | Interpolated latitude and longitude for the address |
| 7 | TIGER/Line ID | Unique ID for the edge the address falls on in the MAF/TIGER database |
| 8 | Side | Side of the street address in on (L for left and R for right) |
| 9 | State | State FIPS Code |
| 10 | County | County FIPS Code |
| 11 | Census Tract | Census Tract Code |
| 12 | Census Block | Census Block Code |
Finding Locations Using Option
| Column | Column Name | Column Description |
|---|---|---|
| 1 | ID | ID from original address list |
| 2 | Address1 | Address from original address list |
| 3 | Matching Result 1 | Results indicating whether or not there was a match for the address (Match, tie, no match) |
| 4 | Matching Result 2 | Results indicating if the match is exact or not (Exact, non-exact) |
| 5 | Address2 | Address the original address matches to |
| 6 | Latitude, Longitude | Interpolated latitude and longitude for the address |
| 7 | TIGER/Line ID | Unique ID for the edge the address falls on in the MAF/TIGER database |
| 8 | Side | Side of the street address in on (L for left and R for right) |
Single Address Look-up
Results
The geocoder takes the address and determines the approximate location offset from the street centerline. An interpolated latitude/longitude coordinate is returned along with the address range the Census Bureau has on that stretch of road. That coordinate is then used to determine the geography that the address is within.
Using the web interface "Find Locations Using" option, the results include the estimated latitude/longitude coordinate, TIGER identifier of the street, and full address range on the road segment.
Using the web interface "Find Geographies Using" option, results are returned for the State, County, Census Tract, and Block the address is located within. In addition, attributes of these pieces of geography, such as an urban/rural indicator are included. To see all of the geography available for the selected address for the time period you selected, type &layers=all at the end of the URL once you get your results back, and refresh the page.
Using the API single record search, any geography that is available for that benchmark/vintage combination in our TIGERweb application can be returned by using the layer code lists in your API request. See the documentation section for additional information on using the API.
Fields in the Output
Documentation
FAQs
Q. How many addresses can I geocode at one time?
A. Up to 10,000
Q. What is the source of your address ranges?
A. The address ranges used in the geocoder are the same address ranges that can be found in the TIGER/Line Shapefiles which are derived from the Master Address File (MAF). The address ranges are potential address ranges, not actual address ranges. Potential ranges include the full range of possible structure numbers even though the actual structures might not exist. The majority of the address ranges we have are for residential areas. There are limited address ranges available in commercial areas. Our address ranges are regularly updated with the most current information we have available to us.
Q. What vintage geography can I get locations for?
A. 2010 Census, Current (during half of the year, current is the same as the most recent American Community Survey) and two previous years of ACS.
Q. How do I format my address(es) for use in the geocoder?
A. Addresses should be formatted in a single line with comma delimiters. The address should consist of:
- Unique ID,
- House Number and Street Name,
- City,
- State,
- ZIP Code
- 1, 1600 Pennsylvania Ave NW, Washington, DC,
- 2, 1600 Pennsylvania Ave NW, , , 20502
- 3, 1600 Pennsylvania Ave NW, Washington, DC
- 4, 1600 Pennsylvania Ave NW, 20502
Q. What coordinate system are the latitude and longitude values?
A. Our latitude and longitude coordinate system is NAD83.
Q. What options do I have if my address isn’t found?
A. Our address ranges consist mainly of residential addresses. If you do not get a result and you know the approximate location of the address, we recommend you use our TIGERweb interactive map viewer. If you do not know the approximate location we recommend you use outside sources to determine the approximate location. We are continually improving our addresses and address ranges. We release updated geography and address ranges at least once per year.
Contact Information
Please send any questions or comments to geo.geocoding.services@census.gov.
