2026 ICD-10-CM Diagnosis Code J84.2Lymphoid interstitial pneumonia

ICD-10-CM Codes›J00–J99›J80-J84›J84

ICD-10-CM J84.2
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

J84.2 is a billable ICD-10-CM diagnosis code for lymphoid interstitial pneumonia. 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. Coders also document this condition as lymphoid interstitial pneumonitis. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified and unspecified lower respiratory disease.

Code Identity

ICD-10-CM Code
J84.2
Billable Status
Yes — Valid for Submission
Code Describes
Lymphoid interstitial pneumonia
Short Description
Lymphoid interstitial pneumonia
Same as the full description in the CMS dataset.
Parent Code
J84
Other interstitial pulmonary diseases

Code Classification

ChapterJ00–J99Diseases of the respiratory system
SectionJ80-J84Other respiratory diseases principally affecting the interstitium
CategoryJ84Other interstitial pulmonary diseases
This CodeJ84.2Lymphoid interstitial pneumonia

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Lymphoid interstitial pneumonitis

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Inclusion Terms

  • Lymphoid interstitial pneumonitis

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Pneumonia(acute) (double) (migratory) (purulent) (septic) (unresolved)
      • interstitial
        • lymphoid
    • Pneumonia(acute) (double) (migratory) (purulent) (septic) (unresolved)
      • lymphoid interstitial
    • Pneumonitis(acute) (primary)
      • interstitial (chronic)
        • lymphoid
    • Pneumonitis(acute) (primary)
      • lymphoid, interstitial

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR RSP016
Other specified and unspecified lower respiratory disease
Default principal diagnosis: inpatient Yes · outpatient Yes

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.

Convert J84.2 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
516.35 Idiopth lym interst pneu
Exact Match The mapping is direct, with no qualifiers.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About J84.2Overview

Is J84.2 (Other interstitial pulmonary diseases) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report lymphoid interstitial pneumonia on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does J84.2 group to?

When lymphoid interstitial pneumonia is the principal diagnosis on an inpatient stay, it groups to MS-DRG 196, 197, 198, with relative weights from 0.7162 to 1.8872 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of J84.2?

Under the General Equivalence Mappings, lymphoid interstitial pneumonia converts to ICD-9-CM 516.35 (idiopth lym interst pneu). The mapping is a direct match.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.