2026 ICD-10-CM Diagnosis Code J15.9Unspecified bacterial pneumonia

ICD-10-CM Codes›J00–J99›J09-J18›J15

ICD-10-CM J15.9
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

J15.9 is a billable ICD-10-CM diagnosis code for unspecified bacterial pneumonia. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 193 through 195, 974 through 976. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Bacterial infections and Pneumonia (except that caused by tuberculosis).

Code Identity

ICD-10-CM Code
J15.9
Billable Status
Yes — Valid for Submission
Code Describes
Unspecified bacterial pneumonia
Short Description
Unspecified bacterial pneumonia
Same as the full description in the CMS dataset.
Parent Code
J15
Bacterial pneumonia, not elsewhere classified

Code Classification

ChapterJ00–J99Diseases of the respiratory system
SectionJ09-J18Influenza and pneumonia
CategoryJ15Bacterial pneumonia, not elsewhere classified
This CodeJ15.9Unspecified bacterial pneumonia

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Bacterial pneumonia
  • Bacterial pneumonia co-occurrent with human immunodeficiency virus infection
  • Bacterial pneumonia with AIDS
  • Bronchopneumonia caused by bacteria
  • Disorder of respiratory system co-occurrent with human immunodeficiency virus infection
  • Healthcare associated bacterial pneumonia
  • Hospital acquired pneumonia
  • Pneumonia caused by aerobic bacteria
  • Pneumonia with AIDS
  • Recurrent bacterial infection
  • Recurrent bacterial pneumonia
  • Recurrent bacterial pneumonia co-occurrent with human immunodeficiency virus infection
  • Recurrent lower respiratory tract infection
  • Recurrent pneumonia
  • Respiratory disorder with AIDS
  • Secondary bacterial pneumonia

Tabular List NotesGuidance

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

Inclusion Terms

  • Pneumonia due to gram-positive bacteria

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)
      • aspiration
        • due to
          • aspiration of microorganisms
            • bacterial
    • Pneumonia(acute) (double) (migratory) (purulent) (septic) (unresolved)
      • bacillus
    • Pneumonia(acute) (double) (migratory) (purulent) (septic) (unresolved)
      • bacterial
    • Pneumonia(acute) (double) (migratory) (purulent) (septic) (unresolved)
      • broncho-, bronchial (confluent) (croupous) (diffuse) (disseminated) (hemorrhagic) (involving lobes) (lobar) (terminal)
        • bacterial
    • Pneumonia(acute) (double) (migratory) (purulent) (septic) (unresolved)
      • lobar (disseminated) (double) (interstitial)
        • bacterial

Clinical ClassificationClinical

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

CCSR INF003
Bacterial infections
Default principal diagnosis: inpatient No · outpatient No
CCSR RSP002
Pneumonia (except that caused by tuberculosis)
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Bacterial Pneumonia

    acute infection of the lung parenchyma caused by bacteria (e.g., streptococcus pneumoniae, haemophilus influenzae, chlamydia pneumoniae, mycoplasma pneumoniae, and legionella pneumophila). signs and symptoms include productive cough, fever, chills, shortness of breath, and chest pain.

Patient EducationClinical

Pneumonia

Pneumonia is an infection in one or both of your lungs. It causes the air sacs of your lungs to fill up with fluid or pus. Pneumonia can range from mild to severe, depending on what caused it, your age, and your overall health.

The full article covers:

  • What is pneumonia?
  • What causes pneumonia?
  • Who is more likely to develop pneumonia?
  • What are the symptoms of pneumonia?
  • What other problems can pneumonia cause?
  • How is pneumonia diagnosed?
  • What are the treatments for pneumonia?
  • Can pneumonia be prevented?

Read the full article at MedlinePlus

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

Convert J15.9 to ICD-9-CMHistory

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

ICD-9-CM
482.9 Bacterial pneumonia NOS
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 J15.9Overview

Is J15.9 (Bacterial pneumonia, not elsewhere classified) a billable code?

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

What MS-DRG does J15.9 group to?

When unspecified bacterial pneumonia is the principal diagnosis on an inpatient stay, it groups to MS-DRG 193, 194, 195, 974, 975, 976, with relative weights from 0.6285 to 2.8860 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of J15.9?

Under the General Equivalence Mappings, unspecified bacterial pneumonia converts to ICD-9-CM 482.9 (bacterial pneumonia NOS). The mapping is a direct match.

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.