ICD-10-CM Code B35.1

Tinea unguium

Version 2021 Billable Code

Valid for Submission

B35.1 is a billable code used to specify a medical diagnosis of tinea unguium. The code is valid for the fiscal year 2021 for the submission of HIPAA-covered transactions. The ICD-10-CM code B35.1 might also be used to specify conditions or terms like distal and lateral subungual onychomycosis, endonyx onychomycosis, fusarium infection, infection caused by scytalidium, infection of toenail, nail bed infection, etc

Short Description:Tinea unguium
Long Description:Tinea unguium

Tabular List of Diseases and Injuries

The Tabular List of Diseases and Injuries is a list of ICD-10 codes, organized "head to toe" into chapters and sections with guidance for inclusions, exclusions, descriptions and more. The following references are applicable to the code B35.1:

Inclusion Terms

Inclusion Terms
These terms are the conditions for which that code is to be used. The terms may be synonyms of the code title, or, in the case of "other specified" codes, the terms are a list of the various conditions assigned to that code. The inclusion terms are not necessarily exhaustive. Additional terms found only in the Alphabetic Index may also be assigned to a code.
  • Dermatophytic onychia
  • Dermatophytosis of nail
  • Onychomycosis
  • Ringworm of nails

Index to Diseases and Injuries

The Index to Diseases and Injuries is an alphabetical listing of medical terms, with each term mapped to one or more ICD-10 code(s). The following references for the code B35.1 are found in the index:


The following clinical terms are approximate synonyms or lay terms that might be used to identify the correct diagnosis code:

  • Distal and lateral subungual onychomycosis
  • Endonyx onychomycosis
  • Fusarium infection
  • Infection caused by Scytalidium
  • Infection of toenail
  • Nail bed infection
  • Nail bed infection
  • Onycholysis
  • Onycholysis due to fungal infection of nail
  • Onychomycosis
  • Onychomycosis caused by Acremonium
  • Onychomycosis caused by Neoscytalidium dimidiatum
  • Onychomycosis due to Botryodiplodia theobromae
  • Onychomycosis due to Curvularia lunata
  • Onychomycosis due to dermatophyte
  • Onychomycosis due to Epidermophyton floccosum
  • Onychomycosis due to Fusarium
  • Onychomycosis due to mold infection
  • Onychomycosis due to Onychocola canadensis
  • Onychomycosis due to opportunistic infection
  • Onychomycosis due to Pseudeurotium ovale
  • Onychomycosis due to Pyrenochaeta unguis hominis
  • Onychomycosis due to Scopulariopsis brevicaulis
  • Onychomycosis due to Scytalidium hyalinum
  • Onychomycosis due to Trichophyton interdigitale
  • Onychomycosis due to Trichophyton mentagrophytes
  • Onychomycosis due to Trichophyton rubrum
  • Onychomycosis due to Trichophyton schoenleinii
  • Onychomycosis due to Trichophyton soudanense
  • Onychomycosis due to Trichophyton tonsurans
  • Onychomycosis due to Trichophyton violaceum
  • Onychomycosis of nail of digit
  • Onychomycosis of toenails
  • Proximal subungual onychomycosis
  • Superficial white onychomycosis
  • Tinea due to Epidermophyton floccosum
  • Tinea due to Trichophyton mentagrophytes variant interdigitale
  • Tinea due to Trichophyton rubrum
  • Tinea due to Trichophyton soudanense
  • Tinea due to Trichophyton tonsurans
  • Tinea due to Trichophyton violaceum
  • Total dystrophic onychomycosis

Clinical Information

  • ONYCHOMYCOSIS-. a fungal infection of the nail usually caused by dermatophytes; yeasts; or nondermatophyte molds.

Diagnostic Related Groups

The ICD-10 code B35.1 is grouped in the following groups for version MS-DRG V38.0 What are Diagnostic Related Groups?
The Diagnostic Related Groups (DRGs) are a patient classification scheme which provides a means of relating the type of patients a hospital treats. The DRGs divides all possible principal diagnoses into mutually exclusive principal diagnosis areas referred to as Major Diagnostic Categories (MDC).
applicable from 10/01/2020 through 09/30/2021.


Convert B35.1 to ICD-9

  • 110.1 - Dermatophytosis of nail

Code Classification

  • Certain infectious and parasitic diseases (A00–B99)

Code History

  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016
    (First year ICD-10-CM implemented into the HIPAA code set)
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
  • FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021

Information for Patients

Tinea Infections

Also called: Ringworm

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.

Symptoms depend on the affected area of the body:

  • Ringworm is a red skin rash that forms a ring around normal-looking skin. A worm doesn't cause it.
  • Scalp ringworm causes itchy, red patches on your head. It can leave bald spots. It usually affects children.
  • Athlete's foot causes itching, burning and cracked skin between your toes.
  • Jock itch causes an itchy, burning rash in your groin area.

Over-the-counter creams and powders will get rid of many tinea infections, particularly athlete's foot and jock itch. Other cases require prescription medicine.

  • Jock itch (Medical Encyclopedia)
  • Ringworm (Medical Encyclopedia)
  • Skin lesion KOH exam (Medical Encyclopedia)
  • Tinea capitis (Medical Encyclopedia)
  • Tinea corporis (Medical Encyclopedia)

[Learn More]