2025 ICD-10-CM Diagnosis Code B35.1
Tinea unguium
- ICD-10-CM Code:
- B35.1
- ICD-10 Code for:
- Tinea unguium
- Is Billable?
- Yes - Valid for Submission
- Chronic Condition Indicator: [1]
- Not chronic
- Code Navigator:
B35.1 is a billable diagnosis code used to specify a medical diagnosis of tinea unguium. The code is valid during the current fiscal year for the submission of HIPAA-covered transactions from October 01, 2024 through September 30, 2025.
Approximate Synonyms
The following list of clinical terms are approximate synonyms, alternative descriptions, or common phrases that might be used by patients, healthcare providers, or medical coders to describe the same condition. These synonyms and related diagnosis terms are often used when searching for an ICD-10 code, especially when the exact medical terminology is unclear. Whether you're looking for lay terms, similar diagnosis names, or common language alternatives, this list can help guide you to the correct ICD-10 classification.
- Distal and lateral subungual onychomycosis
- Endonyx onychomycosis
- Fusarium infection
- Infection caused by Scytalidium
- Infection of skin caused by Neoscytalidium dimidiatum
- Infection of toenail
- Nail bed infection
- Nail bed infection
- Neoscytalidium dermatomycosis
- Onycholysis
- Onycholysis due to fungal infection of nail
- Onychomycosis
- Onychomycosis caused by Acremonium
- Onychomycosis caused by Botryodiplodia theobromae
- Onychomycosis caused by Curvularia lunata
- Onychomycosis caused by Epidermophyton floccosum
- Onychomycosis caused by Fusarium
- Onychomycosis caused by mold
- Onychomycosis caused by Neocucurbitaria unguis-hominis
- Onychomycosis caused by Neoscytalidium dimidiatum
- Onychomycosis caused by Onychocola canadensis
- Onychomycosis caused by Pseudeurotium ovale
- Onychomycosis caused by Scopulariopsis brevicaulis
- Onychomycosis caused by Scytalidium hyalinum
- Onychomycosis caused by Trichophyton mentagrophytes
- Onychomycosis caused by Trichophyton mentagrophytes variant interdigitale
- Onychomycosis caused by Trichophyton rubrum
- Onychomycosis caused by Trichophyton schoenleinii
- Onychomycosis caused by Trichophyton soudanense
- Onychomycosis caused by Trichophyton tonsurans variant tonsurans
- Onychomycosis caused by Trichophyton violaceum
- Onychomycosis due to dermatophyte
- Onychomycosis due to opportunistic infection
- Onychomycosis of nail of digit
- Onychomycosis of toenails
- Proximal subungual onychomycosis
- Scytalidium hyalinum infection of skin
- Superficial white onychomycosis
- Tinea caused by Epidermophyton floccosum
- Tinea caused by Trichophyton mentagrophytes variant interdigitale
- Tinea caused by Trichophyton rubrum
- Tinea caused by Trichophyton soudanense
- Tinea caused by Trichophyton tonsurans
- Tinea caused by Trichophyton violaceum
- Total dystrophic onychomycosis
Clinical Classification
Clinical Classifications group individual ICD-10-CM diagnosis codes into broader, clinically meaningful categories. These categories help simplify complex data by organizing related conditions under common clinical themes.
They are especially useful for data analysis, reporting, and clinical decision-making. Even when diagnosis codes differ, similar conditions can be grouped together based on their clinical relevance. Each category is assigned a unique CCSR code that represents a specific clinical concept, often tied to a body system or medical specialty.
Fungal infections
CCSR Code: INF004
Inpatient Default: Y - Yes, default inpatient assignment for principal diagnosis or first-listed diagnosis.
Outpatient Default: Y - Yes, default outpatient assignment for principal diagnosis or first-listed diagnosis.
Clinical Information
Onycholysis
separation of nail plate from the underlying nail bed. it can be a sign of skin disease, infection (such as onychomycosis) or tissue injury.Onychomycosis
a fungal infection of the nail, usually caused by dermatophytes; yeasts; or nondermatophyte molds.Onycholysis
a nail condition characterized by spontaneous separation of a fingernail or toenail from its nail bed.Nail Loss, PRO-CTCAE|Nail loss|Onycholysis, PRO-CTCAE|PRO-CTCAE, Nail Loss
onycholysis as recorded on the pro-ctcae questionnaire.
Tabular List of Diseases and Injuries
The following annotation back-references are applicable to this diagnosis code. The Tabular List of Diseases and Injuries is a list of ICD-10-CM codes, organized "head to toe" into chapters and sections with coding notes and guidance for inclusions, exclusions, descriptions and more.
Inclusion Terms
Inclusion TermsThese 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 References
The following annotation back-references for this diagnosis code are found in the injuries and diseases index. The Index to Diseases and Injuries is an alphabetical listing of medical terms, with each term mapped to one or more ICD-10-CM code(s).
- - Dermatophytosis (epidermophyton) (infection) (Microsporum) (tinea) (Trichophyton) - B35.9
- - nail - B35.1
- - Infection, infected, infective (opportunistic) - B99.9
- - finger (skin) - L08.9
- - fungus NOS - B49
- - nail (chronic)
- - toe (skin) - L08.9
- - Mycosis, mycotic - B49
- - nails - B35.1
- - Onychia - See Also: Cellulitis, digit;
- - dermatophytic - B35.1
- - Onychomycosis (finger) (toe) - B35.1
- - Tinea (intersecta) (tarsi) - B35.9
- - unguium - B35.1
Convert B35.1 to ICD-9-CM
Below are the ICD-9 codes that most closely match this ICD-10 code, based on the General Equivalence Mappings (GEMs). This ICD-10 to ICD-9 crosswalk tool is helpful for coders who need to reference legacy diagnosis codes for audits, historical claims, or approximate code comparisons.
Dermatophytosis of nail
ICD-9-CM: 110.1
This is a direct match with no additional mapping qualifiers. The absence of a flag generally means the mapping is considered exact or precise. In other words, the ICD-10 code maps cleanly to the ICD-9 code without qualification, approximation, or needing multiple codes.
Patient Education
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.
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.
[Learn More in MedlinePlus]
Code History
- FY 2024 - No Change, effective from 10/1/2023 through 9/30/2024
- FY 2023 - No Change, effective from 10/1/2022 through 9/30/2023
- FY 2022 - No Change, effective from 10/1/2021 through 9/30/2022
- FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021
- FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
- FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
- FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
- FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
- FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016. This was the first year ICD-10-CM was implemented into the HIPAA code set.
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.