A Congressional district is a division of a state that is entitled to elect one member to the House of Representatives. There are currently 435 voting members of Congress representing all 50 states. American Samoa, Guam, the Northern Mariana Islands, Puerto Rico, the US Virgin Islands, and the District of Columbia have one non-voting member each. Congressional districts with non-voting members are numbered 98 (e.g. DC-98).
States with relatively small populations (Alaska, Delaware, Montana, North Dakota, South Dakota, Vermont, and Wyoming) have only a single district. Congressional districts in these single-district states are numbered 00 (e.g. VT-00).
Congressional district boundaries are redrawn after each decennial census. The last major redistricting took place prior to the 2022 House of Representatives elections for the 118th Congress. Smaller adjustments to district boundaries may occur between major redistricting. With the exception of mid-decade redistricting, Congressional district boundaries drawn as part of the 2020 redistricting cycle will remain in effect until the next round of redistricting, scheduled to follow the 2030 census.
The current version of Congressional Districts contains information for the 118th Congress (January 2023-2025). Tables are located in the \DATA subdirectory of the delivery file. Shorelined and unshorelined data is included. Unshorelined data contains the phrase noshore in the file name (e.g. cd_118_usa_noshore.TAB).