ICD-10 Code K65.4 – Sclerosing mesenteritis (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code K65.4 – Sclerosing mesenteritis
What it is
K65.4 identifies sclerosing mesenteritis, a rare inflammatory disorder affecting the mesentery, the tissue that supports the intestines. It may cause thickening, fibrosis, or fat inflammation in that area.
Clinical signs
Clinical features vary; refer to documentation. Common findings include abdominal pain, a palpable mass, bloating, or nonspecific digestive complaints. Imaging or biopsy may be used to support the diagnosis.
When to use this code
Use K65.4 when the provider documents sclerosing mesenteritis, mesenteric panniculitis, or a similar fibrosing inflammatory mesenteric disorder. Code it when the condition is confirmed or clearly stated in the record. If the note only describes abdominal pain or an unexplained mass, check documentation before assigning this code.
Do not use for
Do not use this code for general peritonitis, nonspecific abdominal inflammation, or mesenteric disease that is not documented as sclerosing mesenteritis. Check documentation if the diagnosis is uncertain.
Coding tip
Assign K65.4 only when the clinician names the condition explicitly; avoid inferring it from imaging alone.