A85.1 ICD-10-CA code: Adenoviral encephalitis
A85.1 is the ICD-10-CA code for “Adenoviral encephalitis” in CIHI’s FY 2026–2027 release, in effect from Apr 1, 2026.
Official description
A85.1Adenoviral encephalitis
ICD-10-CA · Canada · Also written A851
Notes for A85.1
As CIHI prints them, with any note A85.1 takes from the headings above it.
Includes
- Adenoviral meningoencephalitis
- Specified viral:• encephalomyelitis NEC• meningoencephalitis NECFrom A85 Other viral encephalitis, not elsewhere classified
- Diseases generally recognized as communicable or transmissibleFrom Chapter 1: Certain infectious and parasitic diseases (A00-B99)
Use additional code
Add a code for this detail when the note documents it.
- Use additional code (U82-U84) to identify resistance to antimicrobial drugsFrom Chapter 1: Certain infectious and parasitic diseases (A00-B99)
Excludes
Conditions classified elsewhere.
- Encephalitis due to:• herpesvirus [herpes simplex] (B00.4)• measles virus (B05.0)• mumps virus (B26.2)• poliomyelitis virus (A80.-)• zoster (B02.0)lymphocytic choriomeningitis (A87.2)myalgic encephalomyelitis (G93.3)From A85 Other viral encephalitis, not elsewhere classified
- Sequelae of:• poliomyelitis (B91)• viral encephalitis (B94.1)From A80-A89 Viral infections of the central nervous system
- Carrier or suspected carrier of infectious disease (Z22.-)certain localized infections - see body system-related chaptersinfectious and parasitic diseases:• complicating pregnancy, childbirth and the puerperium [except obstetrical tetanus] (O98.-)• specific to the perinatal period [except tetanus neonatorum, whooping cough, congenital syphilis, perinatal gonococcal infection and perinatal human immunodeficiency virus [HIV] disease] (P35-P39)influenza and other acute respiratory infections (J00-J22)From Chapter 1: Certain infectious and parasitic diseases (A00-B99)
Where A85.1 sits
- 1ChapterChapter 1: Certain infectious and parasitic diseases (A00-B99)
- 2Block A80-A89Viral infections of the central nervous system
- 3Category A85Other viral encephalitis, not elsewhere classified
- 4Valid code A85.1Adenoviral encephalitis
Source and release
- Data release
- ICD-10-CA · FY 2026–2027
- Effective date
- Apr 1, 2026
- Publisher
- CIHI
This page is built from the ICD-10-CA catalog that Vero Codes reads when it suggests codes: Canadian Institute for Health Information’s FY 2026–2027 release, imported from the publisher’s file and checked against it. The description, notes and structured data come from the same record.
Frequently asked questions
What does ICD-10-CA code A85.1 mean?
A85.1 is the ICD-10-CA code for “Adenoviral encephalitis” in CIHI’s ICD-10-CA FY 2026–2027 release.
Where is A85.1 in ICD-10-CA?
A85.1 sits under A85 Other viral encephalitis, not elsewhere classified, within A80-A89 Viral infections of the central nervous system, within Chapter 1: Certain infectious and parasitic diseases (A00-B99).
What coding notes apply to A85.1?
ICD-10-CA lists Includes, Excludes, Use additional code notes for A85.1, including those from the headings it sits under. They are listed on this page with where each one comes from.
Which ICD-10-CA release does this page use?
It uses CIHI’s FY 2026–2027 release, in effect from Apr 1, 2026 to Mar 31, 2027. It is a reference: confirm the code against the current list and the payer’s rules before you submit it.