ICDcodes.org
FY2027

A83Mosquito-borne viral encephalitis

Not billable

Is A83 billable?

No — A83 is a non-billable header code. A83 groups more specific codes and cannot be submitted on a claim. A valid ICD-10-CM code must be reported at the highest level of specificity available in its branch. Select one of the 9 billable codes beneath A83.

A83 at a glance

CodeA83
DescriptionMosquito-borne viral encephalitis
BillableNo — header code
Code setICD-10-CM FY2027
Valid for encountersOctober 1, 2026 – September 30, 2027

Excludes2 — not included here

The conditions below are not part of A83, but a patient may have both at the same time. When documentation supports it, A83 and the excluded code may both be reported.

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

Includes

Conditions classified to A83.

  • mosquito-borne viral meningoencephalitis

Excludes1 — never code together — inherited from A80-A89

The conditions below can never be reported together with A83 on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.

  • postpolio syndrome (G14)
  • sequelae of poliomyelitis (B91)
  • sequelae of viral encephalitis (B94.1)

Use additional code — inherited from Chapter 1

Report an additional code alongside A83 to fully describe the condition. A83 is sequenced first.

  • code to identify resistance to antimicrobial drugs (Z16.-)

Excludes2 — not included here — inherited from Chapter 1

The conditions below are not part of A83, but a patient may have both at the same time. When documentation supports it, A83 and the excluded code may both be reported.

  • carrier or suspected carrier of infectious disease (Z22.-)
  • certain localized infections - see body system-related chapters
  • infectious and parasitic diseases complicating pregnancy, childbirth and the puerperium (O98.-)
  • infectious and parasitic diseases specific to the perinatal period (P35-P39)
  • influenza and other acute respiratory infections (J00-J22)

What codes fall under A83? (9)

How long has A83 existed?

A83 has been in ICD-10-CM since at least FY2016, the earliest fiscal year on record here.

Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.