ICD-10 Code L02.434 – Carbuncle of left upper limb (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code L02.434 – Carbuncle of left upper limb
What it is
This code identifies a carbuncle, which is a deeper skin infection made up of connected boils, located on the left upper limb. It is used when the documentation specifies the left arm or forearm site.
Clinical signs
Typical findings include a painful, swollen, red, and draining lesion with multiple openings or pus. Clinical features vary; refer to documentation for the exact site, depth, and whether the infection is a carbuncle rather than a simple abscess.
When to use this code
Use this code when the provider documents a carbuncle on the left upper limb, such as the upper arm, forearm, or related left-sided upper extremity site. Code it when the record clearly identifies the lesion as a carbuncle and not another skin infection. Check documentation if laterality or anatomic location is unclear.
Do not use for
Do not use this code for a carbuncle on the right upper limb, trunk, head, or lower limb. Do not use it for a simple furuncle, cellulitis, or nonspecific skin infection unless the documentation supports carbuncle.
Coding tip
Verify both laterality and the exact upper-limb location in the note before assigning L02.434.