2026 ICD-10-CM Diagnosis Code B36.1Tinea nigra

ICD-10-CM Codes›A00–B99›B35-B49›B36

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

B36.1 is a billable ICD-10-CM diagnosis code for tinea nigra. 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. Coders also document this condition as infection by Cladosporium werneckii. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Fungal infections.

Code Identity

ICD-10-CM Code
B36.1
Billable Status
Yes — Valid for Submission
Code Describes
Tinea nigra
Short Description
Tinea nigra
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 CodeB36.1Tinea nigra

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Infection by Cladosporium werneckii
  • Microsporosis nigra
  • Tinea nigra
  • Tinea nigra caused by Phaeoannellomyces werneckii
  • Tinea nigra caused by Stenella araguata

Tabular List NotesGuidance

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

Inclusion Terms

  • Keratomycosis nigricans palmaris
  • Microsporosis nigra
  • Pityriasis nigra

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.

    • Infection, infected, infective(opportunistic)
      • Cladosporium
        • castellanii
    • Infection, infected, infective(opportunistic)
      • Cladosporium
        • werneckii
    • Keratomycosis
      • nigrans, nigricans (palmaris)
    • Microsporosis
      • nigra
    • Pityriasis(capitis)
      • nigra
    • Tinea(intersecta) (tarsi)
      • nigra

Clinical ClassificationClinical

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

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

Patient EducationClinical

Tinea Infections

Tinea is the name of a group of diseases caused by a fungus. Types of tinea include ringworm, athlete's foot and jock itch. These infections are usually not serious, but they can be uncomfortable. You can get them by touching an infected person, from damp surfaces such as shower floors, or even from a pet.

Read the full article at MedlinePlus

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

Convert B36.1 to ICD-9-CMHistory

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

ICD-9-CM
111.1 Tinea nigra
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 B36.1Overview

Is B36.1 (Other superficial mycoses) a billable code?

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

What MS-DRG does B36.1 group to?

When tinea nigra 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 B36.1?

Under the General Equivalence Mappings, tinea nigra converts to ICD-9-CM 111.1 (tinea nigra). 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.