Question 1

What is ICD-10 code A28.2?

Accepted Answer

A28.2 is the ICD-10-CM diagnosis code for extraintestinal yersiniosis. This is a bacterial infection caused by Yersinia bacteria that affects areas outside the intestines, such as the lymph nodes, joints, or bloodstream. It's a rare infectious disease that can cause fever, swollen lymph nodes, and joint pain. A28.2 sits in the ICD-10-CM chapter for certain infectious and parasitic diseases (a00-b99), within the section covering certain zoonotic bacterial diseases (a20-a28).

A28.2 is a billable ICD-10-CM code but does not map to a payment HCC under the CMS-HCC V28, V24, ESRD, or RxHCC risk adjustment models. It can be reported on Medicare Advantage encounter data submissions but it does not contribute to a beneficiary's RAF score and therefore does not affect risk-adjusted payments to the plan.

Verify the specific site of infection (lymph nodes, joints, blood, etc.) in the clinical documentation, as this may require additional specificity codes.

Question 2

Is A28.2 an HCC code?

Accepted Answer

No. A28.2 is a billable ICD-10-CM code but does not map to any payment HCC category under the CMS-HCC V28, V24, ESRD, or RxHCC risk adjustment models. It can still be reported on Medicare Advantage encounter data submissions, but it does not contribute to the beneficiary's Risk Adjustment Factor (RAF) score and therefore does not affect the risk-adjusted capitation payment to the plan. V28 reached 100% phase-in for payment year 2026.

Question 3

Is A28.2 billable?

Accepted Answer

Yes. A28.2 is a billable ICD-10-CM code that can be reported on professional and institutional claims as a primary or secondary diagnosis when the provider documentation supports the specific condition described. Billable codes in ICD-10-CM are coded to the highest level of specificity available for the documented diagnosis. A28.2 is current for fiscal year 2026 and remains in the active CMS ICD-10-CM code set published by the National Center for Health Statistics.

Question 4

What is the V28 vs V24 difference for A28.2?

Accepted Answer

A28.2 does not map to a payment HCC under either the CMS-HCC V28 risk adjustment model or the older V24 model. V28 reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition. Because neither model rewards A28.2 with a risk adjustment factor, it contributes zero to a Medicare Advantage beneficiary's RAF score in either version. Coders should check whether provider documentation supports a more specific child code that does map to a payment HCC.

Question 5

What should coders know when reporting A28.2?

Accepted Answer

Verify the specific site of infection (lymph nodes, joints, blood, etc.) in the clinical documentation, as this may require additional specificity codes Confirm the diagnosis is extraintestinal (outside the intestines) rather than gastrointestinal yersiniosis, which would use a different code

HCC Buddy Code Card

A28.2

Is A28.2 an HCC code?

What This Code Means

Coding Tips

Excludes 1, Do NOT code together

Child Codes

Code Hierarchy

Open A28.2 in the Interactive Encoder

A28.2 ICD-10-CM Code: Extraintestinal yersiniosis

HCC Buddy Code Card

A28.2

Is A28.2 an HCC code?

What This Code Means

Coding Tips

Excludes 1, Do NOT code together

Child Codes

Code Hierarchy

Open A28.2 in the Interactive Encoder