B35.1 — Tinea unguium
B35.1 is a billable, specific ICD-10-CM code for tinea unguium. It is valid for submission on a claim.
Inclusion terms
Alternative wordings a physician may use in the chart for this same code.
- Dermatophytic onychia
- Dermatophytosis of nail
- Onychomycosis
- Ringworm of nails
Risk adjustment
B35.1 does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.
Medicare coverage
B35.1 is named in 16 Medicare coverage policies — 16 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.
- A52996Billing and Coding: Routine Foot Care
- A52998Billing and Coding: Surgical Treatment of Nails
- A56232Billing and Coding: Foot Care
- A56640Billing and Coding: Debridement of Mycotic Nails
How B35.1 is indexed
Coders do not find codes by browsing the tabular list — they look them up in the alphabetic index, under the word the physician wrote. These are the index entries that lead here, so you can see which chart wordings map to B35.1.
- Onychomycosis(finger) (toe)
- Dermatophytosis›nail
- Mycosis, mycotic›nails
- Onychia›dermatophytic
- Ringworm›nails
- Tinea›unguium
- Infection, infected, infective›fungus NOS›nail
- Infection, infected, infective›finger›nail›fungus
- Infection, infected, infective›fungus NOS›skin›toenails
- Infection, infected, infective›nail›finger›fungus
- Infection, infected, infective›nail›toe›fungus
- Infection, infected, infective›toe›cellulitis›fungus
Related codes at this level
Codes that share B35. If B35.1 is not quite right, the correct code is usually one of these.
Questions about B35.1
- Is B35.1 a billable ICD-10-CM code?
- Yes. B35.1 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
- Where does B35.1 sit in the tabular list?
- Certain infectious and parasitic diseases (A00-B99), in the block Mycoses (B35-B49).