J84.114

Billable

Acute interstitial pneumonitis

HCC Category Mapping

V28HCC 280 — Chronic Obstructive Pulmonary Disease

0.334

V24HCC 112 — Fibrosis of Lung and Other Chronic Lung Disorders

0.268

ESRDHCC 112 — Fibrosis of Lung and Other Chronic Lung Disorders

0.000

RxHCCHCC 227 — Sarcoidosis, Pulmonary Alveolar Disorders

0.000

What This Code Means

A sudden inflammation of the lung tissue between the air sacs, often caused by an immune reaction or infection that develops rapidly.

Coding Tips

•Verify the acute onset and distinguish from chronic interstitial pneumonitis (J84.111)
•Document the underlying cause if identifiable, as this may affect coding specificity

Clinical Significance

Acute interstitial pneumonitis (Hamman-Rich syndrome) is a rare, rapidly progressive form of interstitial lung disease that often requires intensive care unit admission and mechanical ventilation. This fulminant condition has high mortality and represents extreme resource utilization. Capturing this diagnosis is important for reflecting the acute severity and complexity of care required.

Documentation Requirements

✓Documentation of acute onset (days to weeks) of respiratory failure without identifiable cause
✓High-resolution computed tomography showing diffuse bilateral ground-glass opacities and consolidation
✓Lung biopsy showing diffuse alveolar damage pattern if performed
✓Exclusion of other causes of acute respiratory distress syndrome including infection, drug reaction, and connective tissue disease
✓Documentation of severity including ventilator requirements, oxygen needs, and ICU status

Excludes 1 — Do NOT code together

pneumocystis pneumonia (B59)

Commonly Confused Codes

J80 — Acute respiratory distress syndrome (ARDS) is a clinical syndrome with a known trigger, while acute interstitial pneumonitis is idiopathic ARDS J84.111 — Idiopathic interstitial pneumonia NOS is used for chronic presentations, not the acute fulminant form J18.9 — Pneumonia unspecified describes infectious pneumonia, not the non-infectious acute interstitial pneumonitis J84.112 — IPF is a chronic progressive disease, unlike the acute onset of Hamman-Rich syndrome

Code Hierarchy

└J84Other interstitial pulmonary diseases └J84.1Other interstitial pulmonary diseases with fibrosis └J84.11Idiopathic interstitial pneumonia └J84.114Acute interstitial pneumonitis

└J84.114Acute interstitial pneumonitis