ICD-10 Code K35.891 – Other acute appendicitis without perforation, with gangrene (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code K35.891 – Other acute appendicitis without perforation, with gangrene
What it is
K35.891 identifies acute appendicitis with gangrene, but without perforation. Use it when documentation shows the appendix is gangrenous and still intact.
Clinical signs
Typical findings include acute right lower quadrant abdominal pain, tenderness, and signs of inflammation. Clinical features vary; refer to documentation for confirmation of gangrene and absence of perforation.
When to use this code
Use this code when the provider documents acute appendicitis with gangrene and specifically states there is no perforation. It fits operative, pathology, or discharge documentation that clearly supports gangrenous appendicitis. Check documentation if the record only says “complicated appendicitis” or does not separate gangrene from perforation.
Do not use for
Do not use it for perforated appendicitis, simple acute appendicitis, or chronic appendicitis. If gangrene or perforation is not documented, check documentation before assigning this code.
Coding tip
Code from the most specific provider statement, and verify that “without perforation” is explicitly supported in the record.