ICD-10 Code B35 – Dermatophytosis (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code B35 – Dermatophytosis
What it is
Dermatophytosis is a fungal infection caused by dermatophytes that affects the skin, hair, or nails. You use this code when the record identifies a dermatophyte infection but does not specify the site.
Clinical signs
Typical findings include scaly, itchy, ring-shaped skin lesions, nail thickening, or hair involvement. Clinical features vary; refer to documentation.
When to use this code
Use B35 when the provider documents dermatophytosis or ringworm without a more specific site code. It also fits cases where the note confirms a dermatophyte infection but does not distinguish between skin, scalp, nail, or foot involvement.
Do not use for
Do not use B35 when the documentation names a more specific dermatophytosis code, such as tinea of a particular site. Do not use it for non-dermatophyte fungal infections; check documentation.
Coding tip
Always look for the anatomic site and organism details before defaulting to B35.