2026 ICD-10-CM Diagnosis Code B43.9Chromomycosis, unspecified
ICD-10-CM Codes›A00–B99›B35-B49›B43
- Billable — Valid for Submission
- Not Chronic
B43.9 is a billable ICD-10-CM diagnosis code for chromomycosis, unspecified. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 867 through 869. Coders also document this condition as cladosporiosis. 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.
- Cladosporiosis
- Phaeohyphomycosis
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
- Chromomycosis - B43.9
External Cause of Injuries IndexGuidance
References for this code in the External Cause of Injuries Index.
- Chromomycosis
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Cerebral Phaeohyphomycosis
cns infections caused by neurotropic dematiaceous fungi that contain melanin in their cell walls. the infections often result in brain abscess; encephalitis; and meningitis in patients who are often immunocompetent. the common causative fungi include members cladophialophora bantiana, exophiala dermatitidis, rhinocladiella mackenziei, and ochroconis gallopavum. r. mackenziei infection is seen almost exclusively in patients from the middle east.Phaeohyphomycosis
opportunistic infections caused by the dematiaceous (darkly pigmented) mitosporic fungi of alternaria, bipolaris, cladosporium, curvularia, and exophiala. these fungi have pigmented hyphae due to melanin in the cell wall. the initial subcutaneous cyst from the infection can become systemic and spread rapidly to renal, pulmonary and cerebral systems (see cerebral phaeohyphomycosis) in an immunocompromised host.
Patient EducationClinical
Fungal Infections
If you have ever had athlete's foot or a yeast infection, you can blame a fungus. A fungus is a primitive organism. Mushrooms, mold and mildew are examples. Fungi live in air, in soil, on plants and in water. Some live in the human body. Only about half of all types of fungi are harmful.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert B43.9 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About B43.9Overview
Is B43.9 (Chromomycosis and pheomycotic abscess) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report chromomycosis, unspecified on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does B43.9 group to?
When chromomycosis, unspecified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 867, 868, 869, with relative weights from 0.7297 to 2.0932 depending on complications. Higher weights mean higher Medicare reimbursement.
What is the ICD-9 equivalent of B43.9?
Under the General Equivalence Mappings, chromomycosis, unspecified converts to ICD-9-CM 117.2 (chromoblastomycosis). 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.
