L66Header code — not billable

Cicatricial alopecia [scarring hair loss]

Chapter
12. Diseases of the skin and subcutaneous tissue
Category
L66
Effective date
October 1, 2026

Related codes in category L66

Frequently asked questions

What is ICD-10 code L66?

L66 is an ICD-10-CM diagnosis code for Cicatricial alopecia [scarring hair loss].

Is L66 a billable code?

No. L66 is a category/header code, not billable on its own — use one of its more specific child codes instead.

What ICD-10-CM chapter is L66 in?

L66 falls under Chapter 12: Diseases of the skin and subcutaneous tissue.

When did L66 become effective?

L66 has been effective since October 1, 2026, per the CMS/CDC ICD-10-CM annual release.

What other codes are related to L66?

L66 belongs to category L66, which includes 12 other codes — see the related codes list on this page.

ICD-10-CM data maintained by CDC/CMS (public domain). Always verify codes with authoritative sources before making coding or billing decisions.