A66.6 Bone and joint lesions of yaws

The ICD-10-CM code for Bone and joint lesions of yaws is A66.6 (FY2026). It is a billable, claim-ready diagnosis code.

Classification

Chapter

1: Certain infectious and parasitic diseases (A00-B99)

Section

A65-A69: Other spirochetal diseases (A65-A69)

Category A66

11 codes (10 billable)

FY2026 Status

Stable since FY2024

Also Known As

ICD-10-CM Alphabetic Index entries that lead to A66.6:

• Henpue, henpuye
• Goundou
• Yaws › ganglion
• Periostitis (albuminosa) (circumscribed) (diffuse) (infective) (monomelic) › yaws (hypertrophic) (early) (late)
• Hydrarthrosis › of yaws (early) (late)
• Yaws › bone lesions
• Ganglion (compound) (diffuse) (joint) (tendon (sheath)) › of yaws (early) (late)
• Osteitis › due to yaws

Inclusion Terms

• Yaws ganglion
• Yaws goundou
• Yaws gumma, bone
• Yaws gummatous osteitis or periostitis
• Yaws hydrarthrosis
• Yaws osteitis
• Yaws periostitis (hypertrophic)

U.S. Hospital Utilization

A66.6 appeared in too few sampled U.S. inpatient stays in 2023 to report a national estimate (AHRQ suppresses counts of 10 or fewer) — a rare inpatient diagnosis.

Source: National Inpatient Sample (NIS), Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality, 2016–2023. National survey-weighted estimates.

Official Coding Guidelines

HIV Infections (TOC entry)

a. Human Immunodeficiency Virus (HIV) Infections .............................................................. 19

Infectious agents causing diseases in other chapters (TOC)

b. Infectious agents as the cause of diseases classified to other chapters ................................. 22

Source: CMS — ICD-10-CM Official Guidelines for Coding and Reporting, FY2026

References

• CMS — ICD-10-CM Official Code Set and Guidelines, FY2026
• CDC/NCHS — ICD-10-CM Files and Browser Tool
• AHRQ — HCUP National Inpatient Sample, Frequencies by Diagnosis Code (2016–2023)