ICD-10 Code J84.114 – Acute interstitial pneumonitis (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code J84.114 – Acute interstitial pneumonitis
What it is
Acute interstitial pneumonitis is a sudden, severe lung illness that causes diffuse inflammation and injury in the lung interstitium and air sacs. It is not the same as chronic interstitial lung disease.
Clinical signs
Clinical features vary; refer to documentation. Typical findings include acute shortness of breath, cough, and rapidly worsening respiratory distress, often with diffuse infiltrates on imaging and no clear infectious cause.
When to use this code
Use this code when the provider documents acute interstitial pneumonitis or a clearly equivalent diagnosis. It fits cases where the record describes an acute inflammatory interstitial lung process rather than a chronic fibrotic disorder. Check documentation if the note only says pneumonitis or interstitial lung disease.
Do not use for
Do not use this code for pneumonia, aspiration pneumonitis, or chronic interstitial lung disease unless the provider specifically documents acute interstitial pneumonitis. If the diagnosis is unclear, check documentation.
Coding tip
Code from the provider’s final diagnosis, not from imaging alone, and verify whether the condition is acute, chronic, or unspecified.