Congressional District - ZIP Code Database TM for the 111th US Congress (April 2009 data)
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.
Download zip code, congressional district, county, FIPS code, city and state information immediately!
Find every ZIP code in any congressional district
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. Other databases list only a single congressional district for each ZIP code.
Please note that more than 3,000 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. We have products which can be used to resolve the district in those cases. Click here for a database which can resolve the district by ZIP+4. Click here for a program which can resolve the district by street address.
The database contains the city name, state abbreviation, all county names and county FIPS codes, MSA/PMSA (if any), and all congressional districts for each of the nearly 42,700 ZIP code defined by the USPS.
You can use this information to plan and execute mailings to campaign contributors and to voters by identifying all ZIP codes which lie fully or partially within the target congressional district.
ZIP codes cross congressional district boundaries
In the real world of ZIP codes and congressional districts, ZIP code boundaries simply do not align with congressional district boundaries. You might be surprised to learn that nearly 15 percent of all ZIP codes cross congressional district boundaries. In fact, there are six ZIP codes which lie in five different congressional districts! Clearly, you cannot assume that a particular ZIP code lies entirely within the one congressional district listed by other ZIP code databases.
Using ZIP code to find the correct congressional district
You cannot determine with 100 percent accuracy the correct congressional district for a given address on the basis of the 5-digit ZIP code alone. You need to know whether or not the ZIP code crosses congressional district boundaries. That information comes from the Congressional District - ZIP Code Database.
For each 5-digit ZIP code, the Congressional District - ZIP Code Database shows whether that ZIP code crosses a congressional district boundary. If not, then that one congressional district is valid for all addresses within that 5-digit ZIP code. There is no need to check the actual street address in this case.
Using street address to find the correct congressional district
If the 5-digit ZIP code does cross a congressional district boundary, you must use the street address to determine the correct congressional district for any address within that 5-digit ZIP code. In this case, we suggest that you use our companion product Perfect Address to find the correct congressional district using the street address.
Other useful data...
Using the Congressional District - ZIP Code Database, you can find every ZIP code which lies partially or completely within a given congressional district. Or you can find all congressional districts which contain some portion of a particular ZIP code. You also can find the cities, counties, and county FIPS codes associated with each congressional district. Or you can identify all ZIP codes which lie within a particular congressional district and also lie within a particular MSA/PMSA.
You can use the Congressional District - ZIP Code Database to identify target ZIP codes for acquiring mailing lists of voters within a congressional district. You can determine whether or not to include each ZIP code by the percentage of the ZIP code which lies within the target congressional district.
The Congressional District - ZIP Code Database is available in a single file covering the entire country. The full database contains approximately 64,000 records. Updated monthly.
The Congressional District - ZIP Code Database also includes a separate congressional member cross-reference database file listing all current members of the 111th Congress, along with their district, party affiliation, address, telephone number, and other pertinent information.