2026 ICD-10-CM Diagnosis Code J99Respiratory disorders in diseases classified elsewhere

ICD-10-CM CodesJ00–J99J96-J99J99

ICD-10-CM J99
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

J99 is a billable ICD-10-CM diagnosis code for respiratory disorders 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. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified and unspecified lower respiratory disease.

Code Identity

ICD-10-CM Code
J99
Billable Status
Yes — Valid for Submission
Code Describes
Respiratory disorders in diseases classified elsewhere
Chapter
J96-J99
Other diseases of the respiratory system

Code Classification

ChapterJ00–J99Diseases of the respiratory system
SectionJ96-J99Other diseases of the respiratory system
CategoryJ99Respiratory disorders in diseases classified elsewhere
This CodeJ99Respiratory disorders in diseases classified elsewhere

Code EditsBilling

Medicare Code Editor checks that affect claim validity for J99.

Manifestation codes describe the manifestation of an underlying disease, not the disease itself, and therefore should not be used as a principal diagnosis.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Acute pulmonary African histoplasmosis
  • Acute pulmonary histoplasmosis
  • African histoplasmosis
  • Allergic disorder of respiratory system
  • Chronic pulmonary African histoplasmosis
  • Chronic pulmonary histoplasmosis
  • Disorder of respiratory system co-occurrent with human immunodeficiency virus infection
  • Disorder of respiratory system due to microscopic polyangiitis
  • Lung disease due to connective tissue disorder
  • Lung involvement associated with another disorder
  • Necrosis of artery
  • Pneumonia caused by Histoplasma
  • Pneumonia caused by Histoplasma capsulatum
  • Pulmonary African histoplasmosis
  • Pulmonary amyloidosis
  • Pulmonary histoplasmosis
  • Pulmonary schistosomiasis
  • Respiratory disorder with AIDS
  • Restrictive lung disease
  • Restrictive lung disease due to amyotrophic lateral sclerosis
  • Restrictive lung disease due to Parkinson disease
  • Restrictive lung mechanics due to neuromuscular disease
  • Vasculitis due to systemic disease

Tabular List NotesGuidance

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

Code First

  • underlying disease, such as:
  • amyloidosis E85
  • ankylosing spondylitis M45
  • congenital syphilis A50
  • cryoglobulinemia D89.1
  • early congenital syphilis A50.0
  • plasminogen deficiency E88.02
  • schistosomiasis B65.0 B65.9

Type 1 Excludes

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 No · outpatient No

Clinical InformationClinical

  • Restrictive Lung Disease

    decreased lung volume and inadequate ventilation due to parenchymal lung disorders (e.g., interstitial pulmonary fibrosis) or extrapulmonary disorders (e.g., scoliosis). patients present with shortness of breath and cough.

Patient EducationClinical

Lung Diseases

When you breathe, your lungs take in oxygen from the air and deliver it to the bloodstream. The cells in your body need oxygen to work and grow. During a normal day, you breathe nearly 25,000 times. People with lung disease have difficulty breathing. Millions of people in the U.S. have lung disease.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert J99 to ICD-9-CMHistory

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

ICD-9-CM
517.8 Lung involv in oth dis
Approximate The match is approximate rather than exact.

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 J99Overview

Is J99 (Respiratory disorders in diseases classified elsewhere) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report respiratory disorders in diseases classified elsewhere on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does J99 group to?

On inpatient claims, respiratory disorders 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 J99 be a principal diagnosis?

No. This is a manifestation code: respiratory disorders in diseases classified elsewhere describes the manifestation of an underlying disease rather than the disease itself, so the underlying condition is sequenced first.

What is the ICD-9 equivalent of J99?

Under the General Equivalence Mappings, respiratory disorders in diseases classified elsewhere converts to ICD-9-CM 517.8 (lung involv in oth dis). The mapping is approximate, so confirm the match fits the documentation.

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.