California Cancer Reporting System Standards Volume I: Abstracting and Coding Procedures
The data field Zip at DX identifies the postal code of the patient’s address at diagnosis.
Enter the five-digit or nine-digit U.S. postal zip code or the proper postal code for any other country.
When entering only five digits, leave the last spaces blank.
Enter 8's in the entire field, if the patient resided outside the U.S. or Canada at time of diagnosis and the zip code is unknown.
To obtain an unknown zip code, consult the U.S. Postal Service National Zip Code and Post Office Directory, published by the U.S. Postal Service, or phone the local post office.
If the code cannot be determined and it is a U.S. or Canadian resident, enter 9's in the entire field.