ICD-10 Code J98.5 – Diseases of mediastinum, not elsewhere classified (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code J98.5 – Diseases of mediastinum, not elsewhere classified
What it is
J98.5 identifies a mediastinal disorder that is not classified elsewhere. Use it when the record documents a disease of the mediastinum, but no more specific ICD-10-CM code applies.
Clinical signs
Clinical features vary; refer to documentation. Mediastinal disease may be noted on imaging or described by symptoms related to nearby structures, but the exact presentation depends on the underlying condition.
When to use this code
Use J98.5 when the provider documents a nonspecific disease of the mediastinum and does not name a more specific diagnosis. It is appropriate for charted mediastinal pathology when the record lacks enough detail for a narrower code. Check documentation if the condition is a mass, tumor, infection, or other defined disorder.
Do not use for
Do not use this code for mediastinal tumors, cysts, abscesses, or other specifically coded conditions when the diagnosis is stated. If the record names a more precise mediastinal disorder, code that condition instead.
Coding tip
Always look for the exact mediastinal diagnosis in the assessment, imaging impression, or discharge summary before defaulting to J98.5.