J84.170
BillableInterstitial lung disease with progressive fibrotic phenotype in diseases classified elsewhere
HCC Category Mapping
V28HCC 278 — Fibrosis of Lung and Other Chronic Lung Disorders
1.091V24HCC 112 — Fibrosis of Lung and Other Chronic Lung Disorders
0.268ESRDHCC 112 — Fibrosis of Lung and Other Chronic Lung Disorders
0.000RxHCCHCC 226 — Fibrosis of Lung and Other Chronic Lung Disorders
0.000What This Code Means
Progressive scarring of lung tissue that develops as part of another disease, leading to worsening lung function over time.
Coding Tips
- •Always code the underlying disease first, then use this code as a secondary diagnosis
- •Ensure documentation clearly indicates progressive fibrotic phenotype
Clinical Significance
Interstitial lung disease with progressive fibrotic phenotype represents a subset of ILDs that behave like IPF with relentless fibrotic progression despite treatment. This is a high-severity manifestation code used as a secondary diagnosis alongside the underlying condition. The progressive fibrotic phenotype indicates patients eligible for antifibrotic therapy regardless of their underlying ILD, reflecting very high resource utilization.
Documentation Requirements
- ✓Documentation of the underlying disease classified elsewhere (e.g., rheumatoid arthritis-ILD, hypersensitivity pneumonitis, sarcoidosis)
- ✓Evidence of progressive fibrotic phenotype: declining forced vital capacity, worsening fibrosis on serial imaging, or worsening symptoms despite treatment
- ✓Serial imaging (high-resolution computed tomography) showing progressive fibrotic changes over time
- ✓Pulmonary function test trends demonstrating decline
- ✓Code the underlying disease first, then J84.170 as a secondary/manifestation code
Code First
Commonly Confused Codes
J84.112 — Idiopathic pulmonary fibrosis is a primary diagnosis; J84.170 is used when progressive fibrosis occurs in OTHER classified diseasesJ84.178 — Other interstitial pulmonary diseases with fibrosis in diseases classified elsewhere covers fibrosis WITHOUT the progressive phenotypeJ84.10 — Pulmonary fibrosis unspecified does not capture the progressive nature or the secondary relationshipJ84.111 — Idiopathic interstitial pneumonia NOS does not specify the progressive fibrotic behavior
Code Hierarchy
└J84Other interstitial pulmonary diseases└J84.1Other interstitial pulmonary diseases with fibrosis└J84.17Other interstitial pulmonary diseases with fibrosis in diseases classified elsewhere└J84.170Interstitial lung disease with progressive fibrotic phenotype in diseases classified elsewhere
└J84.170Interstitial lung disease with progressive fibrotic phenotype in diseases classified elsewhere