ICD-10 Code L66.9 – Cicatricial alopecia, unspecified (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code L66.9 – Cicatricial alopecia, unspecified
What it is
L66.9 identifies scarring hair loss of the scalp or other hair-bearing skin when the exact cicatricial alopecia type is not documented. The term means hair follicles are destroyed and replaced by scar tissue.
Clinical signs
Typical findings include permanent hair loss with smooth, shiny, or atrophic skin and loss of follicular openings. Clinical features vary; refer to documentation.
When to use this code
Use L66.9 when the provider documents cicatricial alopecia but does not specify a subtype such as lichen planopilaris or central centrifugal cicatricial alopecia. It also fits when the chart confirms scarring alopecia and no more detailed diagnosis is available.
Do not use for
Do not use this code for nonscarring hair loss, such as alopecia areata or telogen effluvium. If a specific cicatricial alopecia type is documented, code that condition instead.
Coding tip
Check the note for the exact alopecia subtype before assigning L66.9.