ICD-10 Code J84.178 – Other interstitial pulmonary diseases with fibrosis in diseases classified elsewhere (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code J84.178 – Other interstitial pulmonary diseases with fibrosis in diseases classified elsewhere
What it is
This code identifies an interstitial lung disease with fibrosis that is caused by, or occurs as a manifestation of, another classified condition. Use it when the record links the pulmonary fibrosis to an underlying disease.
Clinical signs
Clinical features vary; refer to documentation. Typical findings may include chronic dyspnea, cough, and imaging or pathology evidence of interstitial fibrosis, with the underlying cause documented elsewhere in the chart.
When to use this code
Use J84.178 when the provider documents pulmonary fibrosis as secondary to another disease and specifies the interstitial pattern. This supports cases where the lung findings are not coded as idiopathic or primary fibrosis. Make sure the underlying condition is also documented and coded when required.
Do not use for
Do not use this code for idiopathic pulmonary fibrosis or for interstitial lung disease without fibrosis. If the fibrosis is not linked to another disease, or the documentation is unclear, check documentation.
Coding tip
Confirm the causal relationship and the underlying disease before assigning J84.178.