ICD-10 Code K36 – Other appendicitis (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code K36 – Other appendicitis
What it is
K36 identifies appendicitis that does not fit a more specific ICD-10 category. Use it when the record clearly supports appendicitis, but the documentation does not specify acute, chronic, or another coded subtype.
Clinical signs
Clinical features vary; refer to documentation. Typical appendicitis findings may include abdominal pain, localized tenderness, nausea, or guarding, but you should code only when the provider documents appendicitis.
When to use this code
Use K36 when the clinician documents “other appendicitis” or an equivalent nonspecific appendicitis diagnosis and no more precise code is available. It also fits cases where appendicitis is confirmed, but the note does not support a specific subtype. Check documentation if the record suggests a different appendiceal disorder.
Do not use for
Do not use K36 for acute appendicitis, chronic appendicitis, or appendicitis with a defined complication when a more specific code applies. Do not assign it for abdominal pain alone or for suspected appendicitis without confirmation.
Coding tip
Code K36 only after confirming the provider’s final diagnosis and that no more specific appendicitis code is documented.