ICD-10-CM 2027
ICD-10 code for ulcers yaws
From the official ICD-10-CM alphabetic index entry “Yaws › ulcers”. Page updated September 29, 2026.
About coding ulcers yaws
The ICD-10-CM code for ulcers yaws is A66.4 (Gummata and ulcers of yaws).
Within A66 (yaws), A66.4 is specifically for Gummata and ulcers of yaws. Related codes cover initial lesions of yaws (A66.0), multiple papillomata and wet crab yaws (A66.1), other early skin lesions of yaws (A66.2), Hyperkeratosis of yaws (A66.3), Gangosa (A66.5), bone and joint lesions of yaws (A66.6), other manifestations of yaws (A66.7), latent yaws (A66.8) and 1 more.
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
In MS-DRG v44.0, it is part of the grouping logic for DRG 606 (Minor Skin Disorders with MCC, relative weight 1.5728) and DRG 607 (Minor Skin Disorders without MCC, relative weight 0.8772), in MDC 09 (Diseases and Disorders of the Skin, Subcutaneous Tissue and Breast), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
Common questions about ulcers yaws ICD-10 codes
What is the ICD-10 code for ulcers yaws?
- A66.4 — Gummata and ulcers of yaws.
Is A66.4 billable?
- Yes. A66.4 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can A66.4 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict A66.4 as a principal diagnosis.
Is A66.4 a CC or MCC?
- No. A66.4 is neither a CC nor an MCC under MS-DRG v44.0.