Question 1

What is ICD-10 code A03.8?

Accepted Answer

A03.8 is the ICD-10-CM diagnosis code for other shigellosis. This code represents a bacterial infection caused by Shigella bacteria that doesn't fit into the more common types of shigellosis. Shigella causes severe diarrhea and intestinal inflammation, typically spread through contaminated food or water. A03.8 sits in the ICD-10-CM chapter for certain infectious and parasitic diseases (a00-b99), within the section covering intestinal infectious diseases (a00-a09).

A03.8 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.

Use this code only when the specific type of Shigella (A, B, C, or Sonnei) is not documented or identified; if the type is specified, use the more specific subcategory codes A03.0-A03.3.

Question 2

Is A03.8 an HCC code?

Accepted Answer

No. A03.8 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 A03.8 billable?

Accepted Answer

Yes. A03.8 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. A03.8 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 A03.8?

Accepted Answer

A03.8 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 A03.8 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 A03.8?

Accepted Answer

Use this code only when the specific type of Shigella (A, B, C, or Sonnei) is not documented or identified; if the type is specified, use the more specific subcategory codes A03.0-A03.3 Verify documentation includes confirmation of Shigella infection through stool culture or other diagnostic testing before coding, and ensure this is not a case of unspecified infectious diarrhea

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A03.8

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A03.8 ICD-10-CM Code: Other shigellosis

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A03.8

Is A03.8 an HCC code?

What This Code Means

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Child Codes

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Work A03.8 in HCC Buddy