A08.4
BillableViral intestinal infection, unspecified
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is A08.4 an HCC code?
No. A08.4 is a billable ICD-10-CM code but does not map to any HCC category in V28, V24, ESRD, or RxHCC.
This code does not map to an HCC category in any model (V28, V24, ESRD, RxHCC).
What This Code Means
A08.4 is the ICD-10-CM diagnosis code for viral intestinal infection, unspecified. A viral infection of the intestines that causes inflammation and digestive symptoms, but the specific virus responsible has not been identified or documented. This is a general diagnosis used when a patient has clear signs of viral gastroenteritis without confirmation of which virus is causing it. A08.4 sits in the ICD-10-CM chapter for certain infectious and parasitic diseases (a00-b99), within the section covering intestinal infectious diseases (a00-a09).
A08.4 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 viral agent cannot be determined; if the causative virus is identified (such as rotavirus, norovirus, or enterovirus), use the more specific code instead.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for A08.4 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Use this code only when the specific viral agent cannot be determined; if the causative virus is identified (such as rotavirus, norovirus, or enterovirus), use the more specific code instead
- •This code is appropriate for cases where viral etiology is suspected or confirmed but the particular virus remains unspecified, and should be accompanied by documentation of gastrointestinal symptoms when applicable