ICD-10 Code L59.9 – Disorder of the skin and subcutaneous tissue related to radiation, unspecified (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code L59.9 – Disorder of the skin and subcutaneous tissue related to radiation, unspecified
What it is
This code identifies a skin or subcutaneous tissue disorder caused by radiation exposure when the exact type is not specified. Use it for radiation-related tissue changes affecting the skin or underlying soft tissue.
Clinical signs
Clinical features vary; refer to documentation. Commonly described findings may include erythema, dryness, desquamation, ulceration, fibrosis, or other localized tissue changes after radiation.
When to use this code
Use L59.9 when the record states a radiation-related disorder of the skin or subcutaneous tissue but does not name a more specific condition. It also fits when the provider documents a radiation injury or effect without further detail. Check documentation if the site, severity, or exact diagnosis is unclear.
Do not use for
Do not use this code for burns, dermatitis, or other skin disorders not linked to radiation. If the documentation names a specific radiation-induced condition, code that more specific diagnosis instead.
Coding tip
Look for the provider’s exact wording and code the most specific radiation-related skin diagnosis supported by the note.