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Census Geocoder

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 1,000 addresses at a time.

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).

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 2013 benchmark. The vintages you see available depends on the benchmark you selected.

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.

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
City and State, or ZIP Code may be left blank, but there must be the appropriate number of commas to represent the blank data, for example:
  • 1, 1600 Pennsylvania Ave NW, Washington, DC,
  • 2, 1600 Pennsylvania Ave NW, , , 20502
are both valid entries, while:
  • 3, 1600 Pennsylvania Ave NW, Washington, DC
  • 4, 1600 Pennsylvania Ave NW, 20502
are both invalid entries.

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.

List of descriptive names for fields in the results

Using the batch submission, results can be:

  • Match/Exact
  • Match/Non-Exact
  • Tie
  • No Match
If a Tie is encountered, there are multiple possible results for that address. The address can be input for single address geocoding to view the multiple results.

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 the 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.

Using the batch submission, the state, county, census tract, and block codes are returned.

Documentation

FAQs

Q. How many addresses can I geocode at one time?

A. Up to 1,000

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, 2012 American Community Survey, 2013 American Community Survey, and Current (half the year current is the same as the most recent American Community Survey).

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
City and State, or ZIP Code may be left blank, but there must be the appropriate number of commas to represent the blank data, for example:
  • 1, 1600 Pennsylvania Ave NW, Washington, DC,
  • 2, 1600 Pennsylvania Ave NW, , , 20502
are both valid entries, while:
  • 3, 1600 Pennsylvania Ave NW, Washington, DC
  • 4, 1600 Pennsylvania Ave NW, 20502
are both invalid entries.

Q. What options do I have if my address isnít 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.


Source: U.S. Census Bureau | Geography | (301) 763-1128 |  Last Revised: May 19, 2014