B35.1 – Tinea unguium
ICD-10-CM 2027 diagnosis code · Mycoses
ICD-10-CM code
B35.1
- Code
B35.1(claims format:B351)- Description
- Tinea unguium
- Billable
- Yes – valid for HIPAA-covered transactions
- Valid for
- Dates of service October 1, 2026 – September 30, 2027 (FY2027)
- Chapter
- 1. Certain infectious and parasitic diseases (A00-B99)
- Block
- B35-B49 Mycoses
- Parent codes
- B35
Notes for B35.1
Applicable to:
- Dermatophytic onychia
- Dermatophytosis of nail
- Onychomycosis
- Ringworm of nails
Notes inherited from parent codes
Instructional notes at a category or block level apply to every code below it.
B35 – Dermatophytosis
Includes:
- favus
- infections due to species of Epidermophyton, Micro-sporum and Trichophyton
- tinea, any type except those in B36.-
Block B35-B49
Index terms for B35.1
Entries in the ICD-10-CM alphabetic index that lead to this code:
- Onychomycosis
- Tinea, unguium
- Ringworm, nails
- Dermatophytosis, nail
- Onychia, dermatophytic
- Mycosis, mycotic, nails
- Infection, infected, infective, fungus NOS, nail
- Infection, infected, infective, nail, toe, fungus
- Infection, infected, infective, toe, nail, fungus
- Infection, infected, infective, finger, nail, fungus
- Infection, infected, infective, nail, finger, fungus
- Infection, infected, infective, toe, cellulitis, fungus
- Infection, infected, infective, fungus NOS, skin, toenails
Related codes in B35
- B35.0 – Tinea barbae and tinea capitisBillable
- B35.2 – Tinea manuumBillable
- B35.3 – Tinea pedisBillable
- B35.4 – Tinea corporisBillable
- B35.5 – Tinea imbricataBillable
- B35.6 – Tinea crurisBillable
- B35.8 – Other dermatophytosesBillable
- B35.9 – Dermatophytosis, unspecifiedBillable
Frequently asked questions
What is ICD-10 code B35.1?
B35.1 is the ICD-10-CM code for tinea unguium, in the block B35-B49 (Mycoses).
Is B35.1 a billable code?
Yes. B35.1 is a billable/specific code that can be used to indicate a diagnosis for reimbursement purposes.
What category does B35.1 belong to?
It belongs to category B35 – Dermatophytosis.
Source: CDC/NCHS ICD-10-CM FY2027 code files, tabular list and index. Reference only – code assignment must follow the official ICD-10-CM guidelines and documentation in the medical record.