Question 1

What is ICD-10 code A04.8?

Accepted Answer

A04.8 is the ICD-10-CM diagnosis code for Other specified bacterial intestinal infections. This code describes bacterial infections of the intestines that don't fit into other specific categories, such as infections caused by less common bacteria. These infections typically cause digestive symptoms like diarrhea, abdominal pain, and nausea. A04.8 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. A04.8 is part of the FY2026 ICD-10-CM code set published by the CMS National Center for Health Statistics and used on Medicare, Medicaid, and commercial claims in the United States.

Question 2

Is A04.8 an HCC code?

Accepted Answer

No. A04.8 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 A04.8 billable?

Accepted Answer

Yes. A04.8 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. A04.8 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 A04.8?

Accepted Answer

A04.8 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 A04.8 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 A04.8?

Accepted Answer

Use this code only when the specific bacterial organism is identified but doesn't have its own dedicated ICD-10-CM code; always try to use more specific codes first (A04.0-A04.7) if the organism is Campylobacter, Shigella, Salmonella, or other common pathogens Document the specific causative organism in the medical record to support medical necessity and ensure accurate coding; this code requires that a bacterial cause is confirmed, not just suspected

A04.8

Is A04.8 an HCC code?

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Open A04.8 in the Interactive Encoder