J84.9Interstitial pulmonary disease, unspecified

J84.9 is the ICD-10-CM diagnosis code for interstitial pulmonary disease, unspecified. It belongs to category J84 (other interstitial pulmonary diseases), block J80-J84 (other respiratory diseases principally affecting the interstitium) and chapter 10 (diseases of the respiratory system). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

Within J84, choose J84.9 (Interstitial pulmonary disease, unspecified) only when documentation doesn't support a more specific option: alveolar and parieto-alveolar conditions (J84.0), with fibrosis (J84.1), lymphoid interstitial pneumonia (J84.2) and other specified interstitial pulmonary diseases (J84.8).

As a secondary diagnosis it is a CC (complication or comorbidity), which can move an inpatient stay into the "with CC" MS-DRG of its family, unless the principal diagnosis excludes it.

In MS-DRG v44.0, it is part of the grouping logic for DRG 196 (Interstitial Lung Disease with MCC, relative weight 1.8336), DRG 197 (Interstitial Lung Disease with CC, relative weight 0.9492) and DRG 198 (Interstitial Lung Disease without CC/MCC, relative weight 0.7259), in MDC 04 (Diseases and Disorders of the Respiratory System), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Before ICD-10, this condition was coded in ICD-9-CM as 516.9 (unspecified alveolar and parietoalveolar pneumonopathy).