ICD-10 Code L43.9 – Lichen planus, unspecified (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code L43.9 – Lichen planus, unspecified
What it is
Lichen planus is an inflammatory skin and mucosal disorder. Use this unspecified code when the record states lichen planus but does not identify a specific site or subtype.
Clinical signs
Typical findings include flat-topped, often purple, itchy papules or plaques. Clinical features vary; refer to documentation when the note does not clearly describe the pattern or location.
When to use this code
Use L43.9 when the provider documents lichen planus without further detail. This may apply when the diagnosis is confirmed, but the chart does not specify oral, genital, nail, or other site involvement. If the documentation names a more specific form, code that instead.
Do not use for
Do not use this code when the record identifies a specific lichen planus subtype or an entirely different lichenoid eruption. Check documentation if the lesion description is incomplete or the diagnosis is uncertain.
Coding tip
Code the most specific lichen planus diagnosis documented; use L43.9 only when no further detail is available.