The revised 2021 Guidelines for ICD-O-3.2 Histology Code and Behavior Update for cases diagnosed 1/1/2021 forward are now available on the NAACCR website. The update includes links to tables listing new codes and other changes and is available in two formats: PDF and Excel. Also available are the 2021 ICD-O-3.2 Update Guidelines.
The NAACCR ICD-O-3 Implementation Work Group highly recommends all users read the guidelines which contain important coding information related to the 2021 update.
ICD-O-3 SEER Site/Histology Validation Lists
The Site/Histology List is not intended to be used for case finding or to determine reportability.
The ICD-O-3 Site/Type Validation program was modified to only allow for the site/histology/behavior combinations listed in this publication. All other cases must be reviewed.
- ICD-O-3 SEER Site/Histology Validation List (06/11/2021): PDF (PDF, 675 KB) or Excel (XLSX, 441 KB)
Refer to the ICD-O-3 Archive for older reference documents.
The International Agency for Research on Cancer (IARC) provides an electronic version of ICD-O-3 on their website. However, the IARC versions are not identical to the versions used in the U.S. See the ICD-O-3 errata on this website and the NAACCR ICD-O-3 implementation guidelines for U.S. instructions.