ICD-10 Code L03.312 – Cellulitis of back [any part except buttock] (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code L03.312 – Cellulitis of back [any part except buttock]
What it is
L03.312 identifies cellulitis involving the back, excluding the buttock. It describes a bacterial skin and soft-tissue infection affecting the posterior trunk.
Clinical signs
Typical findings include localized redness, warmth, swelling, tenderness, and expanding skin inflammation on the back. Clinical features vary; refer to documentation.
When to use this code
Use this code when the provider documents cellulitis on the back and does not specify the buttock. It applies when the infection is clearly limited to the back region. If the note only says “skin infection” or the site is unclear, check documentation before assigning L03.312.
Do not use for
Do not use this code for cellulitis of the buttock or for infections documented at another body site. If the record describes a different diagnosis, code the documented condition instead.
Coding tip
Confirm the anatomic site in the provider note; “back” and “buttock” are coded separately.