2026 ICD-10-CM Diagnosis Code A66Yaws

ICD-10-CM Codes›A00–B99›A65-A69›A66

ICD-10-CM A66
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

A66 is a non-billable ICD-10-CM category code for yaws, so it cannot be submitted on claims. Use a more specific code from this category instead, such as A66.0, A66.1, A66.2, and A66.3.

Code Identity

ICD-10-CM Code
A66
Billable Status
No — Non-Billable Category
Code Describes
Yaws
Chapter
A65-A69
Other spirochetal diseases

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionA65-A69Other spirochetal diseases
CategoryA66Yaws
This CodeA66Yaws

Specific Coding for YawsOverview

Non-specific codes like A66 require more characters. Use one of these billable codes instead:

  • Use A66.0 for Initial lesions of yaws

  • Use A66.1 for Multiple papillomata and wet crab yaws

  • Use A66.2 for Other early skin lesions of yaws

  • Use A66.3 for Hyperkeratosis of yaws

  • Use A66.4 for Gummata and ulcers of yaws

  • Use A66.5 for Gangosa

  • Use A66.6 for Bone and joint lesions of yaws

  • Use A66.7 for Other manifestations of yaws

  • Use A66.8 for Latent yaws

  • Use A66.9 for Yaws, unspecified

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Includes

  • bouba
  • frambesia (tropica)
  • pian

Clinical InformationClinical

  • Yaws

    a systemic non-venereal infection of the tropics caused by treponema pallidum subspecies pertenue.

  • Treponema pallidum

    the causative agent of venereal and non-venereal syphilis as well as yaws.

  • Early Yaws

    early yaws includes primary and secondary stages of yaws, endemic tropical treponemal nonvenereal infection: development of initial lesion at inoculation site followed by widespread dissemination of treponemes and generalized secondary granulomatous lesions that may relapse repeatedly.

  • Late Yaws

    late yaws is the tertiary, non-contagious stage of yaws, endemic tropical treponemal nonvenereal infection. late yaws is characterized by destructive and deforming lesions of the skin, bones, and joints.

  • Yaws

    an endemic, infectious, nonvenereal disease in humans that presents mainly in children younger than 15 years. the disease occurs primarily in warm, humid, tropical areas of africa, asia, south america, and oceania, among poor rural populations where conditions of overcrowding and poor sanitation prevail. infection with treponema pertenue, a subspecies of treponema pallidum, causes the disease.

Patient EducationClinical

Bacterial Infections

Bacteria are tiny organisms (living things) that have only one cell. Under a microscope, they look like balls, rods, or spirals. They can be found almost everywhere on Earth. There are lots of bacteria in and on your body. In fact, your body has about 10 times more bacteria cells than human cells.

The full article covers:

  • What are bacteria?
  • How do bacterial infections spread?
  • What are the treatments for bacterial infections?
  • Can bacterial infections be prevented?

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About A66Overview

Is A66 (Yaws) a billable code?

No. This is a category header that groups the codes for yaws, and headers cannot be submitted on claims. Claims for yaws need a more specific code from this category, such as A66.0, A66.1, and A66.2.