Congressional District - ZIP Code Database for the 117th US Congress (October 2021 data)
Confused about which Congress is which?Members of the 117th US House of Representatives were elected on November 3, 2020, and sworn-in on January 3, 2021. Note that new congressional district boundaries were established in 43 of the 50 states following the 2010 US Census, as required by the US Constitution. Congressional District Database for the 117th Congress is based on the most recent district boundaries, including the states of Virginia, North Carolina, Florida, and Pennsylvania, which recently redrew their congressional district boundaries, as required by the courts.
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 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. 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 42,000 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.
Members of the 117th Congress
ZIP codes cross congressional district boundaries
Using ZIP code to find the correct congressional district
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
Other useful data...
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 database also includes a file containing a list of all the states and territories, with the 2-digit state FIPS code assigned to each state by the US Government.
We update every record in Congressional District Database monthly, so you always receive the latest and most up-to-date data. You can't get more accurate and timely ZIP code data from any other source! We license our ZIP code data directly from the US Postal Service, and collect and cross-check all the other data continuously from a variety of sources.
The Congressional District - ZIP Code Database also includes a separate congressional member cross-reference database file listing all current members of the 117th Congress, along with their district, party affiliation, address, telephone number, and other pertinent information.
The State FIPS code is a 2-digit code assigned by the US Government to uniquely identify each of the 50 states. This code also covers Puerto Rico, Washington DC, US Virgin Islands, and various Pacific territories, which are included with this database for completeness.
The Congressional District field identifies the district of the House of Representatives of the 117th Congress in which all or some portion of the ZIP code lies. If the ZIP code lies in more than one congressional district, the Multi-district flag for the record is set to "Y". For those states with only one representative, and for Puerto Rico, US Virgin Islands, Washington DC, Guam, and Palau the Congressional District field is set to "00". If the state code identifies a territory which has no representation in the US Congress (certain Pacific territories) this field is blank.
The ZIP Code field identifies one ZIP code which lies at least partially within the boundaries of the congressional district identified by the congressional district field and at least partially within the boundaries of the county identified by the county name and FIPS fields. Note that portions of this ZIP code may also lie within the boundaries of other congressional districts and/or counties. The ZIP code field is treated as a text field, not a numeric field. This is to prevent the loss of the leading zeroes in certain ZIP codes when the data is imported into a database program.
The ZIP code type field identifies special kinds of ZIP codes. For normal residential ZIP codes this field is blank. The following codes may appear in this field:
The City Name field identifies the one city associated with that particular ZIP code (and NOT necessarily the county) by the USPS. Note that, in some cases, the city may actually reside in a different county. This apparent error exists because the USPS associates a ZIP code with one "preferred" city name, even if the ZIP code crosses county boundaries. This city name is the name preferred by the USPS for use on mail sent to that one ZIP code.
The State Code is the USPS 2-character state abbreviation, such as CA for California.
The County Name field identifies a county which contains some or all of the ZIP code identified by the ZIP code field. If the ZIP code lies in multiple counties, the Multi-county flag is set to "Y".
The County FIPS Code is a 5-digit field containing the unique numeric identification assigned to the county named by the county name field. The FIPS code is assigned to each county by the US Government. We have combined the 2-digit state FIPS code with the 3-digit county FIPS code to yield a 5-digit code which can be used to uniquely identify each county in the USA. The County FIPS field is also treated as a text field to prevent the loss of leading zeroes.
The ZIP code percent field identifies the percentage of the ZIP code which lies within the common area of the congressional district and the county. This number is not based on area or population, but on actual ZIP+4 address records in the USPS ZIP+4 address database (not included with this database). If the ZIP code lies entirely within the congressional district AND the county, the ZIP code percent value is 100%.
The MSA/PMSA field contains the Metropolitan Statistical Area code or Primary Metropolitan Statistical Area code, if any, in which the ZIP code lies. The MSA/PMSA code is assigned by the Office of Management and Budget of the US Government. See the file msapmsa.txt (included with this product) for a complete list of all valid MSA/PMSA codes.
The Multi-county flag is set to "Y" if the ZIP code lies within multiple counties. If so, then this same ZIP code will appear in some other record in the database.
The Multi-district flag is set to "Y" if the ZIP code lies within multiple congressional districts. If so, then this same ZIP code will appear in some other record in the database. If this flag is blank, you can assume that the congressional district of this record is valid for any address using the ZIP code of this record.
If both flags are blank, you can safely assume that the ZIP code identified in the record lies entirely within the congressional district and within the county identified by the record. In this case the Zip code percent is always 100%. If one or both of these flags is set, then the ZIP code percent field identifies that portion of the ZIP code which resides within both the congressional district and the county.
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