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Comparing Codes Across ICD Versions: Gastroenteritis

While implementation of ICD-11 in the US is likely years away, it is not too early to become familiar and comfortable with the structure and format. If you are a coder like me, you may find it fun to browse the ICD-11 hierarchy and look at some of the codes for conditions you code frequently with ICD-10-CM.

Let’s compare and contrast coding of a common condition, gastroenteritis.


  • These code assignments reflect the closest equivalent code from each code set as of February 2023.
  • Code category comparisons reflect excerpts from the ICD-11 Browser compared to the ICD-10-CM Tabular listing.

As illustrated in the comparisons in the table above, ICD-11 classifies unspecified gastroenteritis within the infectious gastroenteritis hierarchy, whereas ICD-10-CM presumes unspecified gastroenteritis is noninfective. This slight nuance in the classifications underscores the importance of specificity in clinical documentation. Specification of the origin of gastroenteritis (as infective or noninfective) is important for consistent code assignment. Also note that ICD-11 generally uses the ‘Y’ character for “other specified” and the ‘Z’ character for “unspecified” (analogous to characters ‘8’ and ‘9’ in ICD-10-CM).

Looking for more? Visit the WHO website to browse ICD-11 codes or use the ICD-11 coding tool.

While the eventual transition to ICD-11 will doubtless provide challenges, it is the sort of challenge we are ready for. We are coders. This is what we do.

For more code comparisons across ICD versions, click here.


Mary H. Stanfill is Vice President of Consulting for United Audit Systems, Inc. and is the official representative of the IFHIMA to the WHO Family of International Classifications Education and Implementation (EIC) and Morbidity Reference Group (MbRG) workgroups. She has over 35 years of experience in the health information profession, primarily focused on clinical classification of healthcare data. She holds a masters in biomedical informatics and is currently pursuing a doctorate in health informatics.