ICD-10 Code K37 – Unspecified appendicitis (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code K37 – Unspecified appendicitis
What it is
K37 identifies appendicitis when the record does not specify whether it is acute, chronic, or otherwise classified. Use it when documentation only states appendicitis and no further detail is available.
Clinical signs
Typical findings may include right lower quadrant abdominal pain, tenderness, fever, nausea, or vomiting. Clinical features vary; refer to documentation, imaging, and provider assessment.
When to use this code
Use K37 when the clinician documents appendicitis but does not describe the type or acuity. It is appropriate when the chart lacks enough detail to assign a more specific appendicitis code. If later documentation clarifies the condition, code the more specific diagnosis instead.
Do not use for
Do not use K37 when the record specifies acute appendicitis, perforation, abscess, or generalized peritonitis. Check documentation if another appendiceal disorder is named.
Coding tip
Query the provider when appendicitis is mentioned without acuity or complication details.