2026 ICD-10-CM Diagnosis Code B39.1Chronic pulmonary histoplasmosis capsulati

ICD-10-CM Codes›A00–B99›B35-B49›B39

ICD-10-CM B39.1
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

B39.1 is a billable ICD-10-CM diagnosis code for chronic pulmonary histoplasmosis capsulati. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 177 through 179, 974 through 976. Coders also document this condition as chronic pulmonary histoplasmosis. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Fungal infections and Pneumonia (except that caused by tuberculosis).

Code Identity

ICD-10-CM Code
B39.1
Billable Status
Yes — Valid for Submission
Code Describes
Chronic pulmonary histoplasmosis capsulati
Short Description
Chronic pulmonary histoplasmosis capsulati
Same as the full description in the CMS dataset.
Parent Code
B39
Histoplasmosis

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionB35-B49Mycoses
CategoryB39Histoplasmosis
This CodeB39.1Chronic pulmonary histoplasmosis capsulati

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Chronic pulmonary histoplasmosis
  • Pulmonary histoplasmosis

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.

    • Histoplasmosis
      • capsulati
        • pulmonary
          • chronic
    • Pneumonia(acute) (double) (migratory) (purulent) (septic) (unresolved)
      • in (due to)
        • histoplasmosis
          • chronic

Clinical ClassificationClinical

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

CCSR INF004
Fungal 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

  • Histoplasmosis

    infection resulting from exposure to the fungus histoplasma.

  • Histoplasma

    a mitosporic onygenales fungal genus causing histoplasmosis in humans and animals. its single species is histoplasma capsulatum which has two varieties: h. capsulatum var. capsulatum and h. capsulatum var. duboisii. its teleomorph is ajellomyces capsulatus.

  • Histoplasmosis

    a disease caused by the fungus histoplasma capsulatum. it primarily affects the lungs but can also occur as a disseminated disease that affects additional organs. the acute respiratory disease has symptoms similar to those of a cold or flu and it usually resolves without treatment in healthy individuals. the disseminated form is generally fatal if untreated.

Patient EducationClinical

Histoplasmosis

Histoplasmosis is an infection caused by a fungus called Histoplasma. This fungus is common in the central and eastern United States, especially around the Ohio and Mississippi River valleys. It can also be found in parts of Central and South America, Africa, Asia, and Australia.

The full article covers:

  • What is histoplasmosis?
  • How do you get histoplasmosis?
  • What are the symptoms of histoplasmosis?
  • How is histoplasmosis diagnosed?
  • What are the treatments for histoplasmosis?

Read the full article at MedlinePlus

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

Convert B39.1 to ICD-9-CMHistory

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

ICD-9-CM
115.05 Histoplasm caps pneumon
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 B39.1Overview

Is B39.1 (Histoplasmosis) a billable code?

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

What MS-DRG does B39.1 group to?

When chronic pulmonary histoplasmosis capsulati is the principal diagnosis on an inpatient stay, it groups to MS-DRG 177, 178, 179, 974, 975, 976, with relative weights from 0.7550 to 2.8860 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of B39.1?

Under the General Equivalence Mappings, chronic pulmonary histoplasmosis capsulati converts to ICD-9-CM 115.05 (histoplasm caps pneumon). The mapping is approximate, so confirm the match fits the documentation.

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.