ICD-10 Code L03.9 – Cellulitis and acute lymphangitis, unspecified (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code L03.9 – Cellulitis and acute lymphangitis, unspecified
What it is
This code identifies an unspecified bacterial infection of the skin and nearby lymphatic vessels. Use it when the record states cellulitis or acute lymphangitis but does not specify the site or type.
Clinical signs
Typical findings include localized redness, warmth, swelling, tenderness, and sometimes streaking along lymphatic channels. Clinical features vary; refer to documentation.
When to use this code
Use L03.9 when the clinician documents cellulitis or acute lymphangitis without naming an anatomic site, such as arm, leg, face, or trunk. It also fits cases where the note confirms a skin/soft tissue infection but the location remains unclear. Check documentation if the provider later specifies the site.
Do not use for
Do not use this code when the documentation names a specific body site that has its own more precise cellulitis code. Do not assign it for abscess, dermatitis, or noninfectious redness unless cellulitis is clearly documented.
Coding tip
Query for the affected site whenever the note says “cellulitis” without location, because a more specific code may be available.