Alternate Name	Item#	Length	Source of Standard	Column #
County at Diagnosis (CoC) County (pre-96 SEER/CoC)	90	3	FIPS/SEER	156-158

Description
Code for the county of the patient's residence at the time the tumor was diagnosed. For U.S. residents, standard codes are those of the FIPS publication "Counties and Equivalent Entities of the United States, Its Possessions, and Associated Areas." If the patient has multiple tumors, the county codes may be different for each tumor.

Detailed standards have not been set for Canadian provinces/territories. Use code 998 for Canadian residents. 

Codes (in addition to FIPS and Geocodes)

998	Known town, city, state, or country of residence but county code not known AND a resident outside of the state of reporting institution (must meet all criteria)
999	County unknown

Note: See Appendix A for standard FIPS county codes. See EDITS Table BPLACE.DBF in Appendix B for geocodes used by CoC.

Note: SEER does not use code 998. CoC uses country geocodes for nonresidents of the United States (see Appendix B) and 998 for residents of other states.