ICD-10 Code L98.423 – Non-pressure chronic ulcer of back with necrosis of muscle (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code L98.423 – Non-pressure chronic ulcer of back with necrosis of muscle
What it is
This code identifies a chronic, non-pressure ulcer on the back that extends into muscle tissue. Use it when documentation shows a full-thickness ulcer with necrosis of muscle, not a pressure injury.
Clinical signs
Findings may include an open wound on the back with tissue loss, chronic nonhealing drainage, and visible or documented muscle necrosis. Clinical features vary; refer to documentation.
When to use this code
Use L98.423 when the provider documents a chronic ulcer on the back and specifies necrosis of muscle. It fits non-pressure ulcers involving the back, including ulcers described as full-thickness or deep tissue loss. Check documentation if the site, chronicity, or depth is unclear.
Do not use for
Do not use this code for pressure ulcers, surgical wounds, or skin breakdown without muscle necrosis. If the record does not confirm a non-pressure chronic ulcer of the back, check documentation.
Coding tip
Confirm both the anatomic site and the depth of involvement before assigning L98.423.