ICD-10-CM 2027 diagnosis code

L66.1Lichen planopilaris

Not billable — use a more specific code

L66.1 is a header code, so it can't be reported by itself. Choose one of the 4 more specific codes beneath it.

Code last changed in FY2025 (effective October 1, 2024). Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About L66.1

L66.1 is the ICD-10-CM diagnosis code for lichen planopilaris. It belongs to category L66 (cicatricial alopecia [scarring hair loss]), 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 4 subcodes must be used instead.

Within L66 (cicatricial alopecia [scarring hair loss]), L66.1 is specifically for lichen planopilaris. Related codes cover Pseudopelade (L66.0), Folliculitis decalvans (L66.2), Perifolliculitis capitis abscedens (L66.3), Folliculitis ulerythematosa reticulata (L66.4), other cicatricial alopecia (L66.8) and cicatricial alopecia, unspecified (L66.9).

To report this condition, pick the subcode that matches the documentation: L66.10 (unspecified), L66.11 (planopilaris), L66.12 (alopecia) and L66.19 (planopilaris).

It has been part of ICD-10-CM since the code set took effect on October 1, 2015, and changed in FY2025 (expanded into subcodes).

Before ICD-10, this condition was coded in ICD-9-CM as 697.0 (lichen planus).

Specific codes under L66.1

Notes that apply from higher levels

Instructions written at a parent level also apply to L66.1.

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

Codes whose notes reference L66.1

L43Excludes1

ICD-9-CM equivalent

Converter →

697.0Lichen planusapproximate

From the CMS 2018 General Equivalence Mappings (GEMs), the final GEMs release.

Code history

2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027

FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
FY2025 (effective 10/1/2024): Expanded — no longer billable

Common questions about L66.1

Is L66.1 billable?: No. L66.1 is a header code. Report one of its more specific subcodes instead.
What is the ICD-9 code for L66.1?: The CMS General Equivalence Mappings map L66.1 to ICD-9-CM 697.0.