ICD-10 Code L40 – Psoriasis (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code L40 – Psoriasis
What it is
L40 identifies psoriasis, a chronic inflammatory skin disease that causes accelerated skin cell growth. It is used when the record documents psoriasis without a more specific subtype.
Clinical signs
Typical findings include well-demarcated erythematous plaques with silvery scale, often on the scalp, elbows, knees, or trunk. Clinical features vary; refer to documentation.
When to use this code
Use L40 when the clinician diagnoses psoriasis but does not specify a subtype or site-specific variant. It may also apply when documentation simply states “psoriasis” in the assessment or problem list. If the note identifies a more specific form, code that diagnosis instead.
Do not use for
Do not use L40 for dermatitis, eczema, or nonspecific rash without documented psoriasis. Check documentation if the record names a specific psoriatic condition that requires a different code.
Coding tip
Review the assessment and pathology or dermatology notes for a more specific psoriasis subtype before assigning the unspecified code.