2027 ICD-10-CM Diagnosis Code A66.0Initial lesions of yaws

ICD-10-CM Codes›A00–B99›A65-A69›A66

ICD-10-CM A66.0
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

A66.0 is a billable ICD-10-CM diagnosis code for initial lesions of yaws. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 606 through 607. Coders also document this condition as initial frambesial ulcer. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Parasitic, other specified and unspecified infections.

Code Identity

ICD-10-CM Code
A66.0
Billable Status
Yes — Valid for Submission
Code Describes
Initial lesions of yaws
Short Description
Initial lesions of yaws
Same as the full description in the CMS dataset.
Parent Code
A66
Yaws

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionA65-A69Other spirochetal diseases
CategoryA66Yaws
This CodeA66.0Initial lesions of yaws

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Initial frambesial ulcer
  • Initial lesion of yaws

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to A66.0: its own notes plus those printed at A66, block A65-A69, and Chapter 1. A note printed at a category, block or chapter applies to every code under it.

Includes

Further defines, or gives examples of, the content of the category.

From A66 Yaws applies to 10 codes
  • bouba
  • frambesia (tropica)
  • pian
From Chapter 1 (A00-B99) Certain infectious and parasitic diseases applies to 1,068 codes
  • diseases generally recognized as communicable or transmissible

Applicable To

Conditions this code is used for: synonyms of the title or, for "other specified" codes, the conditions assigned to it. The list is not exhaustive.

  • Chancre of yaws
  • Frambesia, initial or primary
  • Initial frambesial ulcer
  • Mother yaw

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From Block A65-A69 Other spirochetal diseases applies to 28 codes
From Chapter 1 (A00-B99) Certain infectious and parasitic diseases applies to 1,068 codes
  • carrier or suspected carrier of infectious disease (Z22.-)
  • certain localized infections - see body system-related chapters
  • infectious and parasitic diseases complicating pregnancy, childbirth and the puerperium (O98.-)
  • infectious and parasitic diseases specific to the perinatal period (P35-P39)
  • influenza and other acute respiratory infections (J00-J22)

Use Additional Code

Add a second code, after this one, to fully describe the condition.

From Chapter 1 (A00-B99) Certain infectious and parasitic diseases applies to 1,068 codes
  • code to identify resistance to antimicrobial drugs (Z16.-)

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR INF009
Parasitic, other specified and unspecified infections
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Yaws

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

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.

Convert A66.0 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
102.0 Initial lesions yaws
Exact Match The mapping is direct, with no qualifiers.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About A66.0Overview

What is the ICD-10 code for initial lesions of yaws?

The ICD-10-CM code for initial lesions of yaws is A66.0 (sometimes written as A660). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is A66.0 (Yaws) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report initial lesions of yaws on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does A66.0 group to?

When initial lesions of yaws is the principal diagnosis on an inpatient stay, it groups to MS-DRG 607, 606, with relative weights from 0.8772 to 1.5721 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of A66.0?

Under the General Equivalence Mappings, initial lesions of yaws converts to ICD-9-CM 102.0 (initial lesions yaws). The mapping is a direct match.