ICD-10-CM 2027 diagnosis code

L66Cicatricial alopecia [scarring hair loss]

Not billable — use a more specific code

L66 is a header code, so it can't be reported by itself. Choose one of the 7 more specific codes beneath it.

Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About L66

L66 is the ICD-10-CM diagnosis code for cicatricial alopecia [scarring hair loss]. It belongs to block L60-L75 (disorders of skin appendages) and chapter 12 (diseases of the skin and subcutaneous tissue). It is a header code, so it can't be reported by itself; one of its 7 subcodes must be used instead.

To report this condition, pick the subcode that matches the documentation: L66.0 (Pseudopelade), L66.1 (planopilaris), L66.2 (decalvans), L66.3 (abscedens), L66.4 (reticulata), L66.8 (alopecia) and L66.9 (unspecified).

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Specific codes under L66

Notes that apply from higher levels

Instructions written at a parent level also apply to L66.

Broader instructions also apply from L60-L75 Disorders of skin appendages and Chapter 12: Diseases of the skin and subcutaneous tissue.

Code history

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2027

FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
No changes since FY2016.

Common questions about L66

Is L66 billable?: No. L66 is a header code. Report one of its more specific subcodes instead.