A90
BillableDengue fever [classical dengue]
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is A90 an HCC code?
No. A90 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
A90 is the ICD-10-CM diagnosis code for dengue fever [classical dengue]. Dengue fever is a viral infection spread by mosquitoes that causes fever, headache, muscle and joint pain, and rash. It is also known as classical dengue and is typically a self-limiting illness that resolves within a week or two. A90 sits in the ICD-10-CM chapter for certain infectious and parasitic diseases (a00-b99), within the section covering arthropod-borne viral fevers and viral hemorrhagic fevers (a90-a99).
A90 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.
A90 is used for uncomplicated dengue fever; if the patient develops severe dengue (dengue hemorrhagic fever or dengue shock syndrome), use codes A91 instead.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for A90 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •A90 is used for uncomplicated dengue fever; if the patient develops severe dengue (dengue hemorrhagic fever or dengue shock syndrome), use codes A91 instead
- •This code does not require a fifth character; document the clinical presentation and any complications to ensure accurate coding and appropriate severity assessment
Excludes 1 — Do NOT code together
- dengue hemorrhagic fever (A91)