2027 ICD-10-CM Diagnosis Code B39.9Histoplasmosis, unspecified
ICD-10-CM Codes›A00–B99›B35-B49›B39
- Billable — Valid for Submission
- Not Chronic
B39.9 is a billable ICD-10-CM diagnosis code for histoplasmosis, unspecified. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 867 through 869, 974 through 976. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Fungal infections.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Abscess of medulla of spinal cord caused by Histoplasma
- Abscess of spinal cord caused by fungus
- Bilateral neovascularization of choroid of eye
- Classical histoplasmosis mediastinal fibrosis
- Cutaneous histoplasmosis
- Fungal meningitis
- Gingivitis caused by Histoplasma
- Histo spot
- Histoplasma dacryoadenitis
- Histoplasma infection of central nervous system
- Histoplasmosis
- Histoplasmosis syndrome of bilateral eyes
- Histoplasmosis syndrome of left eye
- Histoplasmosis syndrome of right eye
- Histoplasmosis with AIDS
- Histoplasmosis with pericarditis
- Histoplasmosis with retinitis
- Infection of lacrimal gland caused by fungus
- Infection of spinal cord caused by Histoplasma
- Infection of stomach caused by Histoplasma
- Meningitis caused by Histoplasmosis
- Neovascularization of choroid of left eye
- Neovascularization of choroid of right eye
- Ocular histoplasmosis syndrome
- Primary cutaneous histoplasmosis
- Spinal cord abscess
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to B39.9: its own notes plus those printed at B39, block B35-B49, and Chapter 1. A note printed at a category, block or chapter applies to every code under it.
Includes
Further defines, or gives examples of, the content of the category.
- diseases generally recognized as communicable or transmissible
Excludes2
Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.
- carrier or suspected carrier of infectious disease (Z22.-)
- certain localized infections - see body system-related chapters
- infectious and parasitic diseases complicating pregnancy, childbirth and the puerperium (O98.-)
- infectious and parasitic diseases specific to the perinatal period (P35-P39)
- influenza and other acute respiratory infections (J00-J22)
Code First
The underlying condition named in the note is sequenced before this code.
Use Additional Code
Add a second code, after this one, to fully describe the condition.
- code to identify resistance to antimicrobial drugs (Z16.-)
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Referenced in Other NotesGuidance
Instructional notes printed at other codes that name B39.9, its category, or a range that includes it.
Code First 1
These codes say to code first a condition named in the note, and B39.9 is one of the conditions named.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Chorioretinitis See Also: Inflammation, chorioretinal;
histoplasmic B39.9
histoplasmosis B39.9
Histoplasmosis B39.9
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Histoplasmosis
infection resulting from exposure to the fungus histoplasma.
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 B39.9 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About B39.9Overview
What is the ICD-10 code for histoplasmosis, unspecified?
The ICD-10-CM code for histoplasmosis, unspecified is B39.9 (sometimes written as B399). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is B39.9 (Histoplasmosis) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report histoplasmosis, unspecified on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does B39.9 group to?
When histoplasmosis, unspecified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 974, 976, 975, 867, 869, 868, with relative weights from 0.6784 to 3.0488 depending on complications. Higher weights mean higher Medicare reimbursement.
Does B39.9 need an additional code?
When the condition applies, yes. The Use Additional Code note at B39, which applies to B39.9, reads: code for any associated manifestations, such as: endocarditis (I39); meningitis (G02); pericarditis (I32); retinitis (H32). The additional code is reported after B39.9.
What is the ICD-9 equivalent of B39.9?
Under the General Equivalence Mappings, histoplasmosis, unspecified converts to ICD-9-CM 115.90 (histoplasmosis NOS). The mapping is approximate, so confirm the match fits the documentation.
