ICD-10 Code L03.31 – Cellulitis of trunk (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code L03.31 – Cellulitis of trunk
What it is
L03.31 identifies cellulitis involving the trunk, meaning an acute bacterial infection of the skin and subcutaneous tissue on the chest, abdomen, back, or flank. Use it when documentation clearly states cellulitis of the trunk.
Clinical signs
Typical findings include localized redness, warmth, swelling, tenderness, and spreading skin inflammation on the trunk. Clinical features vary; refer to documentation for the exact site and whether the infection is superficial or deeper.
When to use this code
Use this code when the provider documents cellulitis specifically affecting the trunk, rather than an extremity or another body region. It also fits cases described as abdominal wall or chest wall cellulitis if the record supports trunk involvement. If the site is unclear, check documentation.
Do not use for
Do not use L03.31 for abscess, furuncle, or generalized skin infection unless cellulitis of the trunk is also documented. Do not assign it when the infection is coded to a more specific site.
Coding tip
Confirm the anatomic location in the note; “trunk” should be documented or clearly implied before you code L03.31.