2026 ICD-10-CM Diagnosis Code J84.178Other interstitial pulmonary diseases with fibrosis in diseases classified elsewhere
ICD-10-CM Codes›J00–J99›J80-J84›J84
- Billable — Valid for Submission
- Not Chronic
J84.178 is a billable ICD-10-CM diagnosis code for other interstitial pulmonary diseases with fibrosis in diseases classified elsewhere. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 196 through 198. The code is a manifestation code that cannot be reported as the principal diagnosis. Coders also document this condition as diffuse pulmonary neurofibromatosis. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified and unspecified lower respiratory disease.
Code Identity
Code Classification
Code EditsBilling
Medicare Code Editor checks that affect claim validity for J84.178.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Diffuse pulmonary neurofibromatosis
- Rheumatoid fibrosing alveolitis
- Rheumatoid lung disease
Tabular List NotesGuidance
Coding notes and annotation back-references applicable to this code.
Inclusion Terms
- Interstitial pneumonia (nonspecific) (usual) due to collagen vascular disease
- Interstitial pneumonia (nonspecific) (usual) in diseases classified elsewhere
- Organizing pneumonia due to collagen vascular disease
- Organizing pneumonia in diseases classified elsewhere
Code First
- underlying disease, such as:
- progressive systemic sclerosis M34.0
- rheumatoid arthritis M05.00 M06.9
- systemic lupus erythematosis M32.0 M32.9
These terms are the conditions for which that code is to be used. The terms may be synonyms of the code title, or, in the case of "other specified" codes, the terms are a list of the various conditions assigned to that code. The inclusion terms are not necessarily exhaustive. Additional terms found only in the Alphabetic Index may also be assigned to a code.
Certain conditions have both an underlying etiology and multiple body system manifestations due to the underlying etiology. For such conditions, the ICD-10-CM has a coding convention that requires the underlying condition be sequenced first followed by the manifestation. Wherever such a combination exists, there is a "use additional code" note at the etiology code, and a "code first" note at the manifestation code. These instructional notes indicate the proper sequencing order of the codes, etiology followed by manifestation.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
- Pneumonia (acute) (double) (migratory) (purulent) (septic) (unresolved) - J18.9
- interstitial - J84.9
- due to
- collagen vascular disease - J84.178
- known underlying cause - J84.178
- in disease classified elsewhere - J84.178
- lymphocytic (due to collagen vascular disease) (in diseases classified elsewhere) - J84.178
- non-specific - J84.89
- due to
- collagen vascular disease - J84.178
- known underlying cause - J84.178
- in diseases classified elsewhere - J84.178
- due to collagen vascular disease - J84.178
- in diseases classified elsewhere - J84.178
- organizing - J84.89
- due to
- collagen vascular disease - J84.178
- known underlying cause - J84.178
- in diseases classified elsewhere - J84.178
External Cause of Injuries IndexGuidance
References for this code in the External Cause of Injuries Index.
- Pneumonia(acute) (double) (migratory) (purulent) (septic) (unresolved)
- interstitial
- due to
- collagen vascular disease
- Pneumonia(acute) (double) (migratory) (purulent) (septic) (unresolved)
- interstitial
- due to
- known underlying cause
- Pneumonia(acute) (double) (migratory) (purulent) (septic) (unresolved)
- interstitial
- in disease classified elsewhere
- Pneumonia(acute) (double) (migratory) (purulent) (septic) (unresolved)
- interstitial
- lymphocytic (due to collagen vascular disease) (in diseases classified elsewhere)
- Pneumonia(acute) (double) (migratory) (purulent) (septic) (unresolved)
- interstitial
- non-specific
- due to
- collagen vascular disease
- Pneumonia(acute) (double) (migratory) (purulent) (septic) (unresolved)
- interstitial
- non-specific
- due to
- known underlying cause
- Pneumonia(acute) (double) (migratory) (purulent) (septic) (unresolved)
- interstitial
- non-specific
- in diseases classified elsewhere
- Pneumonia(acute) (double) (migratory) (purulent) (septic) (unresolved)
- interstitial
- usual
- due to collagen vascular disease
- Pneumonia(acute) (double) (migratory) (purulent) (septic) (unresolved)
- interstitial
- usual
- in diseases classified elsewhere
- Pneumonia(acute) (double) (migratory) (purulent) (septic) (unresolved)
- organizing
- due to
- collagen vascular disease
- Pneumonia(acute) (double) (migratory) (purulent) (septic) (unresolved)
- organizing
- due to
- known underlying cause
- Pneumonia(acute) (double) (migratory) (purulent) (septic) (unresolved)
- organizing
- in diseases classified elsewhere
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Patient EducationClinical
Interstitial Lung Diseases
Interstitial lung disease is the name for a large group of diseases that inflame or scar the lungs. The inflammation and scarring make it hard to get enough oxygen. The scarring is called pulmonary fibrosis.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Code History & ChangesHistory
Replacement J84.178 replaces the following previously assigned code(s):
- J84.17 - Oth interstit pulmon dis w fibrosis in dis classd elswhr
Questions About J84.178Overview
Is J84.178 a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report other interstitial pulmonary diseases with fibrosis in diseases classified elsewhere on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does J84.178 group to?
On inpatient claims, other interstitial pulmonary diseases with fibrosis in diseases classified elsewhere maps to MS-DRG 196, 197, 198, with relative weights from 0.7162 to 1.8872 depending on complications. Higher weights mean higher Medicare reimbursement.
Can J84.178 be a principal diagnosis?
No. This is a manifestation code: other interstitial pulmonary diseases with fibrosis in diseases classified elsewhere describes the manifestation of an underlying disease rather than the disease itself, so the underlying condition is sequenced first.
Footnotes
[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.
