L66 – Cicatricial alopecia [scarring hair loss]
ICD-10-CM 2027 diagnosis code · Disorders of skin appendages
ICD-10-CM code
L66
- Code
L66(claims format:L66)- Description
- Cicatricial alopecia [scarring hair loss]
- Billable
- No – use a more specific code below
- Valid for
- Dates of service October 1, 2026 – September 30, 2027 (FY2027)
- Chapter
- 12. Diseases of the skin and subcutaneous tissue (L00-L99)
- Block
- L60-L75 Disorders of skin appendages
Billable codes under L66
L66 is a header code and cannot be used on claims. Choose the most specific code:
- L66.0 – PseudopeladeBillable
- L66.1 – Lichen planopilarisHeader (more codes below)
- L66.2 – Folliculitis decalvansBillable
- L66.3 – Perifolliculitis capitis abscedensBillable
- L66.4 – Folliculitis ulerythematosa reticulataBillable
- L66.8 – Other cicatricial alopeciaHeader (more codes below)
- L66.9 – Cicatricial alopecia, unspecifiedBillable
Notes inherited from parent codes
Instructional notes at a category or block level apply to every code below it.
Block L60-L75
Excludes1 (not coded here):
- congenital malformations of integument (Q84.-)
Frequently asked questions
What is ICD-10 code L66?
L66 is the ICD-10-CM code for cicatricial alopecia [scarring hair loss], in the block L60-L75 (Disorders of skin appendages).
Is L66 a billable code?
No. L66 is a header code with more specific child codes; report one of the billable codes listed above.
Source: CDC/NCHS ICD-10-CM FY2027 code files, tabular list and index. Reference only – code assignment must follow the official ICD-10-CM guidelines and documentation in the medical record.