Congressional District#

The Congressional District products contain a list of all ZIP codes in the congressional district for each member of the 118th US Congress and includes a congressional member cross-reference database (cdlist.csv).

There are two (2) levels of accuracy available for Congressional District data:

  1. The 5-digit ZIP Code Level: Congressional District ZIP code Database (CDZ), provides all 5-digit zip codes and counties which lie within the boundaries of every Congressional District of the U.S. This database identifies the ZIP codes which lie in multiple districts and the districts they lie in, but can NOT correctly resolve the congressional district for a particular street address.

  2. The 9-digit ZIP+4 Level: Congressional District Database (CDD), provides the current congressional district for each ZIP+4 defined by the U.S. 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. A ZIP+4 record normally applies to a single block of a street or sometimes to a single address of a street, which means that this database resolves the district correctly down to the block or address level.