ICD-10 Code L43 – Lichen planus (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code L43 – Lichen planus
What it is
L43 identifies lichen planus, an inflammatory skin and mucous membrane disorder. It is used when documentation names lichen planus without a more specific subtype.
Clinical signs
Typical findings include flat-topped, polygonal, violaceous papules, often with pruritus. Oral or other mucosal involvement may also be documented; clinical features vary, so refer to documentation.
When to use this code
Use L43 when the provider diagnoses lichen planus and does not specify a different coded subtype. It fits cases involving skin, oral, or other mucosal disease if the record supports lichen planus. If the note is unclear, check documentation before coding.
Do not use for
Do not use L43 for nonspecific rash, dermatitis, or another confirmed inflammatory skin disorder. If the record names a different condition or subtype, code that diagnosis instead.
Coding tip
Code to the highest documented specificity, and confirm whether the site or subtype is identified in the note.