A83

Non-billable

Mosquito-borne viral encephalitis

A83 is the ICD-10-CM code for Mosquito-borne viral encephalitis. It is a non-billable category code — use a more specific child code such as A83.0 for billing.

Status
Header (non-billable)
Chapter
A00-B99
Subcodes
9
Edition
FY2026

A00-B99 Certain infectious and parasitic diseases

What this means — in plain language

MedlinePlus · NIH

What is encephalitis? Encephalitis is inflammation (swelling) of the brain. It can happen when an infection or medical condition that affects the brain activates your immune system. The inflammation can cause a wide range of symptoms. In extreme cases, it can lead to brain damage, stroke , or even death. What causes encephalitis? There are different types of encephalitis, based on what the cause is. The two main…

Read more about Encephalitis at MedlinePlus ↗

Source: U.S. National Library of Medicine (MedlinePlus). Informational only — not medical advice.

Includes

  • mosquito-borne viral meningoencephalitis

Excludes2 — not included here

  • Venezuelan equine encephalitis (A92.2)
  • West Nile fever (A92.3-)
  • West Nile virus (A92.3-)

Frequently asked questions

What is ICD-10 code A83?
A83 is the ICD-10-CM code for "Mosquito-borne viral encephalitis". It falls under A00-B99 Certain infectious and parasitic diseases.
Is A83 a billable code?
No — A83 is a non-billable header code. Use a more specific child code (such as A83.0) for billing.
What are the subcodes of A83?
A83 has 9 more specific child codes, including A83.0, A83.1, A83.2.

Source: CMS ICD-10-CM FY2026. For informational purposes only — not medical advice. See our medical disclaimer.

Look up another ICD-10 code or condition

Powered by Eleplan

Free ICD-10 lookup is just the start. Eleplan keeps the whole care plan in one place.

Diagnoses, medications, documents, appointments, and the whole care team — organized and always in sync, with Ellie, your AI care assistant, on top of it. Free to start.