Question 1

What is ICD-10 code A66?

Accepted Answer

A66 is the ICD-10-CM diagnosis code for yaws. A66 sits in the ICD-10-CM chapter for certain infectious and parasitic diseases (a00-b99), within the section covering other spirochetal diseases (a65-a69).

Header codes like A66 cannot be reported on claims directly; they organize child codes that share clinical context. Coders should select the billable child code that matches the documented presentation and then verify its current source-backed HCC mapping. Do not infer a child code or risk adjustment value from the header alone.

Question 2

Is A66 an HCC code?

Accepted Answer

A66 is a non-billable header code. Choose the billable child code supported by the documentation, then check that child's current V28 mapping.

Question 3

Is A66 billable?

Accepted Answer

No. A66 is a header (non-billable) ICD-10-CM code. Header codes sit at a higher level of the diagnosis hierarchy and exist to organize a family of more specific child codes. Per ICD-10-CM coding guidelines, a header code cannot be reported on a claim as the diagnosis, coders must select a billable child code from the A66 hierarchy that matches the highest level of specificity supported by the provider's documentation. Payers reject header codes submitted as the primary diagnosis.

Question 4

Which HCC does A66 map to under V28?

Accepted Answer

A66 is not billable. Choose a billable child code before checking its V28 mapping.

Question 5

What RAF reference is published for A66?

Accepted Answer

A66 is not billable. Choose a billable child code before checking a V28 reference coefficient.

Question 6

What is the V28 vs V24 difference for A66?

Accepted Answer

A66 is not billable. Choose a billable child code before comparing V28 with a historical V24 reference.

Question 7

What documentation supports A66?

Accepted Answer

A66 is not billable. Choose the supported billable child code before checking mapping or documentation requirements.

HCC Buddy Code Card

A66

Get the V28 mapping + MEAT cheat sheet

What This Code Means

Includes

Child Codes

Code Hierarchy

Work A66 in HCC Buddy

A66 ICD-10-CM Code: Yaws