A04.2
BillableEnteroinvasive Escherichia coli infection
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is A04.2 an HCC code?
No. A04.2 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
A04.2 is the ICD-10-CM diagnosis code for enteroinvasive escherichia coli infection. This is a bacterial infection caused by a specific type of E. coli bacteria that invades the intestinal lining, causing inflammation and diarrhea. It's typically acquired through contaminated food or water. A04.2 sits in the ICD-10-CM chapter for certain infectious and parasitic diseases (a00-b99), within the section covering intestinal infectious diseases (a00-a09).
A04.2 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 documentation specifies enteroinvasive E. coli (EIEC) rather than other pathogenic E. coli strains, as different subtypes have different codes (e.g., A04.0 for ETEC, A04.1 for EAEC).
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for A04.2 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Verify documentation specifies enteroinvasive E. coli (EIEC) rather than other pathogenic E. coli strains, as different subtypes have different codes (e.g., A04.0 for ETEC, A04.1 for EAEC)
- •Look for associated symptoms like bloody diarrhea, abdominal cramping, or fever in the clinical notes to support the diagnosis and determine if additional codes are needed