FAQs#

General#

How many versions are there for the Congressional District Database?#

There are two (2) versions of the Congressional District Database. There is [1] The Congressional District ZIP Code database, which provides congressional district data at the 5 digit zip code level, and there is [2] the Congressional District Database, which provides Congressional District data at the ZIP+4 (or 9 digit zip code) level.

What is the Congressional District Data ?#

Congressional District Database (CDD)#

The Congressional District Database (CDD) lists the current congressional district of the 118th Congress for each ZIP+4 defined by the US Postal Service. The ZIP+4 records of this database provide the necessary resolution to find the correct district within a ZIP code which lies in two or more districts. Please note that the ZIP Codes representing US Military bases in foreign counties and ships at sea are NOT included in thisd atabase because they are not part of any congressional district for voting purposes.

Congressional District Zip Code Database (CDZ)#

The Congressional District - ZIP Code Database lists all ZIP codes and counties which lie within the boundaries of every congressional district in each of the fifty states. This database lists every combination of ZIP code and congressional district which exists in the real world.

Please note that more than 6000 5-digit ZIP codes lie in multiple congressional districts. This database identifies the ZIP codes which lie in multiple districts and the districts they lie in, but it cannot correctly resolve the congressional district for a particular street address in those cases. To resolve the congressional district to the street address level for ZIP codes which lie in multiple districts, you must have the street address or the ZIP+4.

How often is Congressional District Database updated?#

Monthly

Where can I find the product homepage?#

Congressional District Database (CDD)#

https://www.zipinfo.com/products/cdd/cdd.htm

Congressional District Zip Code Database (CDZ)#

https://www.zipinfo.com/products/cdz/cdz.htm

Where can I find the product release notes?#

https://releasenotes.melissa.com/reference-data/congressional-district/

Where can I find the product documentation?#

https://docs.melissa.com/reference-data/congressional-district/congressional-district-index.html

Where can I find the product sample files?#

Congressional District Database (CDD)#

https://www.zipinfo.com/samples/cddsam.txt

Congressional District Zip Code Database (CDZ)#

https://www.zipinfo.com/samples/cdzsam.txt

Specific#

How many fields are in this database?#

The “cdz.txt” file contains 12 different fields.

What fields are returned in this database?#

ST_FIPS, CDist, ZIP, Type, City, ST, County, FIPS, Percent, MSAPMSA, Multi-cnty, Multi-dist

How is this product sorted?#

The Congressional District ZIP Code Database records are sorted in ascending order by State FIPS Code, Congressional District, and ZIP Code.