ICD-O-3 Guidelines

The revised 2022 Guidelines for ICD-O-3.2 Histology Code and Behavior UpdateExternal Web Site Policy for cases diagnosed 1/1/2022 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 2022 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 2022 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.

Refer to the ICD-O-3 Archive Icon indicating linked file is archived content. for older reference documents.

The International Agency for Research on Cancer (IARCExternal Web Site Policy) 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 guidelinesExternal Web Site Policy for U.S. instructions.