ICD-10 Code L40.0 – Psoriasis vulgaris (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code L40.0 – Psoriasis vulgaris
What it is
L40.0 identifies psoriasis vulgaris, the common plaque form of psoriasis. It is a chronic inflammatory skin condition marked by recurrent, well-defined plaques.
Clinical signs
Typical findings include erythematous plaques with silvery scale, often on the elbows, knees, scalp, or lower back. Clinical features vary; refer to documentation.
When to use this code
Use this code when the provider documents plaque psoriasis, psoriasis vulgaris, or chronic psoriasis with classic plaque lesions. Choose it for confirmed skin involvement, not for nonspecific dermatitis or an unconfirmed rash. Check documentation if the subtype is unclear.
Do not use for
Do not use L40.0 for other psoriasis types, such as guttate, pustular, or inverse psoriasis, unless the record clearly states plaque psoriasis. Do not assign it when psoriasis is only suspected.
Coding tip
Match the documented psoriasis subtype exactly, and query the provider if the note says only “psoriasis.”