ICD-10 Code L40.51 – Distal interphalangeal psoriatic arthropathy (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code L40.51 – Distal interphalangeal psoriatic arthropathy
What it is
This code identifies psoriatic arthritis that primarily affects the distal interphalangeal joints, the joints closest to the fingertips. Use it when documentation specifically states distal interphalangeal psoriatic arthropathy.
Clinical signs
Common findings include pain, swelling, and stiffness in the distal finger or toe joints, often with psoriasis-related nail changes. Clinical features vary; refer to documentation.
When to use this code
Use L40.51 when the provider documents psoriatic arthropathy with clear distal interphalangeal joint involvement. It is appropriate when the record distinguishes this pattern from other psoriatic arthritis sites. Check documentation if the joint location is not specified.
Do not use for
Do not use this code for psoriasis without arthritis, or for nonspecific joint pain alone. Avoid it when the note describes another psoriatic arthritis pattern or the joint site is not confirmed.
Coding tip
Assign this code only when the distal interphalangeal joint involvement is explicitly documented.