B351 - Fungal infection of the fingernails or toenails

International Classification of Diseases

Last updated: 10/3/2025

What is a ICD-10 Code?

ICD-10 (International Classification of Diseases, 10th Revision) codes are used to classify and code all diagnoses, symptoms, and procedures recorded in association with hospital care. These codes provide a standardized way to track health conditions and their treatment outcomes.

Detailed Description

Tinea unguium is a fungal infection that affects the nails, most commonly the toenails but can also affect fingernails. This condition is caused by the same types of fungi that cause athlete's foot and other skin infections. The infection typically makes nails thick, discolored (yellow, brown, or white), brittle, and sometimes causes them to separate from the nail bed. It's more common in adults and can be persistent, often requiring several months of treatment with antifungal medications. The condition is not dangerous but can be cosmetically concerning and may cause discomfort if nails become very thick.

Additional Information

Treatment typically involves oral or topical antifungal medications and can take 3-12 months. Good nail hygiene and keeping feet dry can help prevent recurrence. This office visit code suggests routine monitoring or initial evaluation of the nail infection.

Category

Infectious Disease/Dermatology

Medical Specialty

Dermatology, Family Medicine, Podiatry

Expected Costs

We expect this to normally be in the range of:

$150 - $400

This is an estimate based on typical billing patterns. Your actual cost may vary depending on your insurance coverage, provider location, and specific circumstances.

What's Required Before This

  • Clinical examination of affected nails
  • Possible nail sample testing to confirm fungal infection

What to Expect After

  • Regular monitoring during treatment
  • Follow-up visits to assess treatment response
  • Possible repeat testing to confirm cure

Why Understanding This Code Matters

On Your Medical Bill

This code appears on your medical bills to identify the specific service, procedure, drug, or medical diagnosis you received. Understanding what it means helps you verify you're being charged correctly and know what to expect.

For Your Health

Knowing what this code represents helps you understand your treatment plan, ask better questions during appointments, and track your healthcare journey more effectively.

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