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ICD-O-3 Guidelines
The revised 2018 Guidelines for ICD-O-3 Histology Code and Behavior Update
for cases diagnosed 1/1/2018 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 2018 ICD-O-3 Update Guidelines and 1/10/2018 Errata/Change document.
The NAACCR ICD-O-3 Implementation Work Group highly recommends all users read the guidelines which contain important coding information related to the 2018 update.
ICD-O-3 SEER Site/Histology Validation List
This site/type list is provided in both PDF and Excel formats:
- ICD-O-3 SEER Site/Histology Validation List (06/18/2019): PDF (PDF, 662 KB) or Excel (XLS, 1.3 MB)
- Errata for 07/11/2019 List (PDF, 9 KB)
- Errata for 06/18/2019 List (PDF, 12 KB)
- Errata for 03/26/2018 List (PDF, 15 KB)
- Errata for 01/17/2018 List (PDF, 41 KB)
Note: The Site/Histology List is not intended to be used for case finding or to determine reportability.
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.
