ICD-10 Code K38.9 – Disease of appendix, unspecified (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code K38.9 – Disease of appendix, unspecified
What it is
K38.9 identifies a disorder of the appendix when the record does not specify the exact condition. Use it for appendix-related disease that is documented, but not named more precisely.
Clinical signs
Clinical features vary; refer to documentation. Appendix disease may present with right lower quadrant pain, abdominal tenderness, nausea, or fever, but the code itself does not confirm a specific diagnosis.
When to use this code
Use K38.9 when the provider documents a disease of the appendix and no further detail is available. It also fits cases where the appendix is noted as abnormal or diseased, but the exact disorder is not stated.
If the chart later specifies appendicitis, appendiceal abscess, or another defined condition, code that more specific diagnosis instead. Check documentation before defaulting to an unspecified code.
Do not use for
Do not use this code for acute appendicitis or other clearly identified appendiceal disorders. It is also wrong when the record describes a normal appendix or a non-appendiceal abdominal condition.
Coding tip
Review the operative note, imaging report, and discharge diagnosis for a more specific appendiceal condition before assigning K38.9.