A national 113th Congressional District codes file is available for download.
The text files contain tab-delimited records for each congressional district. The records are of the format:
|Field Name||Field Description||Example|
|STATE||State Postal Code||AL|
|STATEFP||State FIPS Code||01|
|CD113FP||113th Congressional District FIPS Code||6|
|NAMELSAD||Current name and the translated legal/statistical area description for the congressional district||Congressional District 6|