ICD-10 Code A66.4 – Gummata and ulcers of yaws (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code A66.4 – Gummata and ulcers of yaws
What it is
A66.4 identifies late-stage yaws with gummatous lesions or ulcers. Use it when documentation describes destructive skin or soft tissue lesions caused by yaws.
Clinical signs
Findings may include ulcerative lesions, gummas, and tissue destruction consistent with yaws. Clinical features vary; refer to documentation for the exact lesion type and site.
When to use this code
Use A66.4 when the provider documents gummata or ulcers due to yaws, especially in a confirmed or clearly stated late manifestation. It also fits when the record links a chronic ulcer or gumma directly to yaws. Check documentation if the diagnosis is uncertain or only a history of yaws is noted.
Do not use for
Do not use this code for nonspecific skin ulcers, other treponemal diseases, or yaws without gummatous or ulcerative involvement. Check documentation if the lesion cause is not clearly identified.
Coding tip
Assign A66.4 only when the record explicitly connects the ulcer or gumma to yaws.