2026 ICD-10-CM Diagnosis Code B36.9Superficial mycosis, unspecified

ICD-10-CM Codes›A00–B99›B35-B49›B36

ICD-10-CM B36.9
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

B36.9 is a billable ICD-10-CM diagnosis code for superficial mycosis, unspecified. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 606 through 607. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Fungal infections.

Code Identity

ICD-10-CM Code
B36.9
Billable Status
Yes — Valid for Submission
Code Describes
Superficial mycosis, unspecified
Short Description
Superficial mycosis, unspecified
Same as the full description in the CMS dataset.
Parent Code
B36
Other superficial mycoses

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionB35-B49Mycoses
CategoryB36Other superficial mycoses
This CodeB36.9Superficial mycosis, unspecified

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Acute fungal otitis externa
  • Acute infective otitis externa
  • Bilateral chronic otitis externa of external auditory canals caused by fungus
  • Bilateral external auditory canal chronic otitis externa
  • Bilateral otitis externa of external auditory canals caused by fungus
  • Chronic infective otitis externa of bilateral external auditory canals
  • Chronic infective otitis externa of left external auditory canal
  • Chronic infective otitis externa of right external auditory canal
  • Chronic mycotic otitis externa
  • Chronic mycotic otitis externa of left external auditory canal
  • Chronic mycotic otitis externa of right external auditory canal
  • Chronic otitis externa of left external auditory canal
  • Chronic otitis externa of right external auditory canal
  • Dermal mycosis
  • Dermatomycosis with AIDS
  • Disorder of skin co-occurrent with human immunodeficiency virus infection
  • Disseminated cutaneous mycosis
  • Fungal dermatitis of eyelid
  • Infection of skin and subcutaneous tissue caused by fungus
  • Infective otitis externa of bilateral ears
  • Otitis externa of left external auditory canal caused by fungus
  • Otitis externa of right external auditory canal caused by fungus
  • Otomycosis
  • Skin disorder with AIDS
  • Subcutaneous mycosis
  • Superficial mycosis

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.

    • Dermatitis(eczematous)
      • fungus
    • Dermatomycosis
    • Ear
      • tropical NEC
    • Infection, infected, infective(opportunistic)
      • fungus NOS
        • skin
    • Infection, infected, infective(opportunistic)
      • mycotic NOS
        • skin NOS
    • Infection, infected, infective(opportunistic)
      • skin (local) (staphylococcal) (streptococcal)
        • due to fungus
    • Infection, infected, infective(opportunistic)
      • skin (local) (staphylococcal) (streptococcal)
        • mycotic
    • Mycosis, mycotic
      • cutaneous NEC
    • Mycosis, mycotic
      • ear
    • Mycosis, mycotic
      • skin NEC
    • Otitis(acute)
      • externa
        • in (due to)
          • mycosis NEC
    • Otitis(acute)
      • externa
        • mycotic NEC
    • Otitis(acute)
      • externa
        • tropical NEC
    • Otomycosis(diffuse) NEC

Clinical ClassificationClinical

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

CCSR INF004
Fungal infections
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Otomycosis

    fungus infection of the external ear, usually by aspergillus species

  • Aspergillus

    a genus of mitosporic fungi containing about 100 species and eleven different teleomorphs in the family trichocomaceae.

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 B36.9 to ICD-9-CMHistory

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

ICD-9-CM
111.9 Dermatomycosis NOS
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 B36.9Overview

Is B36.9 (Other superficial mycoses) a billable code?

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

What MS-DRG does B36.9 group to?

When superficial mycosis, unspecified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 606, 607, with relative weights from 0.9064 to 1.5132 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of B36.9?

Under the General Equivalence Mappings, superficial mycosis, unspecified converts to ICD-9-CM 111.9 (dermatomycosis NOS). 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.