ICD-10 Code L02.42 – Furuncle of Limb (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code L02.42 – Furuncle of limb
What it is
L02.42 identifies a furuncle, or boil, located on an arm or leg. It is a localized infection of a hair follicle that forms a painful, pus-filled nodule.
Clinical signs
Typical findings include a tender, red, swollen lump with central pus or drainage. Surrounding warmth or induration may be present; clinical features vary, so refer to documentation.
When to use this code
Use this code when the record clearly documents a furuncle on an upper or lower limb. You may apply it whether the lesion is described as a boil or localized skin abscess on the limb, if the provider specifies furuncle. Check documentation when the site is unclear.
Do not use for
Do not use L02.42 for furuncles on the face, trunk, groin, or other non-limb sites. Do not use it when the documentation describes cellulitis, carbuncle, or an unspecified skin abscess instead.
Coding tip
Verify the exact anatomic site in the note, because limb location drives code selection.