ICD10BillableValid for clinical use
ICD-10 Code A66.3: Hyperkeratosis of yaws
Reviewed by HealthAssure Clinical TeamUpdated 26 May 2026
What is this code?
ICD-10 codes are diagnosis classification codes used in healthcare records, reporting, coding workflows, and billing support. This code sits within the broader ICD-10 area for Certain infectious and parasitic diseases (A00-B99).
When is it used?
- May be used when a clinician documents hyperkeratosis of yaws in a patient's medical record.
- May appear in hospital records, claims, referrals, and clinical documentation.
- This code can be used as a clinically usable diagnosis entry in standardized coding workflows.
What it does not mean
- A code alone does not explain severity, treatment plan, or outcome.
- A medical code should not be treated as a substitute for a doctor's diagnosis or advice.
Code hierarchy
chapter
1Certain infectious and parasitic diseases (A00-B99)
block
A65-A69Other spirochetal diseases
category
A66Yaws
currentA66
Official coding notes
Inclusion terms
- Ghoul hand
- Hyperkeratosis, palmar or plantar (early) (late) due to yaws
- Worm-eaten soles
Where you may see this code
You may see this code in hospital records, discharge summaries, insurance claims, encounter documentation, referrals, or other healthcare billing and coding records.
Related specialists
Infectious Disease SpecialistGeneral Physician
Related codes
Sibling codes
A66.0Initial lesions of yawsbillableA66.1Multiple papillomata and wet crab yawsbillableA66.2Other early skin lesions of yawsbillableA66.4Gummata and ulcers of yawsbillableA66.5GangosabillableA66.6Bone and joint lesions of yawsbillableA66.7Other manifestations of yawsbillableA66.8Latent yawsbillableA66.9Yaws, unspecifiedbillable
Mapped diagnoses and classifications
Coding guidelines
Compatibility
Legacy and official ICD code match exactly.
Legacy codes
A66.3
Common synonyms
Hyperkeratosis of yaws
Frequently asked questions
About this content
This page is prepared by HealthAssure's clinical team using official coding standards from ICD-10. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.