ICD-10 Code L66.1 – Lichen planopilaris (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code L66.1 – Lichen planopilaris
What it is
Lichen planopilaris is a scarring inflammatory disorder of the scalp that destroys hair follicles. Use this code when documentation identifies this specific form of lichen planus affecting hair-bearing areas.
Clinical signs
Typical findings include patchy scalp hair loss, perifollicular redness, scale, and symptoms such as itching or burning. Clinical features vary; refer to documentation if the diagnosis is not clearly stated.
When to use this code
Assign L66.1 when the provider documents lichen planopilaris or confirms scarring alopecia due to this condition. It may also fit follow-up visits for known disease, if the chart still supports the diagnosis.
Do not use for
Do not use this code for nonscarring alopecia, general lichen planus without scalp involvement, or hair loss of unclear cause. Check documentation when the record does not specify lichen planopilaris.
Coding tip
Look for the words “scarring alopecia” and “lichen planopilaris” together, because the exact diagnosis drives correct code selection.