Is A86 a billable ICD-10-CM code?

Yes. A86 is a billable, specific ICD-10-CM code and is valid for submission on a claim.

Where does A86 sit in the tabular list?

Certain infectious and parasitic diseases (A00-B99), in the block Viral and prion infections of the central nervous system (A80-A89).

A86

A86 — Unspecified viral encephalitis

Billable / specific codeICD-10-CM

A86 is a billable, specific ICD-10-CM code for unspecified viral encephalitis. It is valid for submission on a claim.

Inclusion terms

Alternative wordings a physician may use in the chart for this same code.

Viral encephalomyelitis NOS
Viral meningoencephalitis NOS

Other codes that can never be billed with A86

These codes carry an Excludes1 note pointing at A86. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading A86 alone.

A88Other viral infections of central nervous system, not elsewhere classified

Risk adjustment

A86 does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.

Medicare coverage

A86 is named in 9 Medicare coverage policies — 9 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.

A56612Billing and Coding: CT of the Head
A58710Billing and Coding: MolDX: Molecular Syndromic Panels for Infectious Disease Pathogen Identification Testing
A58710Billing and Coding: MolDX: Molecular Syndromic Panels for Infectious Disease Pathogen Identification Testing
A58720Billing and Coding: MolDX: Molecular Syndromic Panels for Infectious Disease Pathogen Identification Testing

How A86 is indexed

Coders do not find codes by browsing the tabular list — they look them up in the alphabetic index, under the word the physician wrote. These are the index entries that lead here, so you can see which chart wordings map to A86.

Encephalitis›acute
Encephalitis›endemic(viral)
Encephalitis›epidemic NEC(viral)
Encephalitis›infectious NEC(acute) (virus)
Encephalitis›postviral NEC
Encephalitis›viral, virus
Meningoencephalitis›acute NEC
Meningoencephalitis›infectious(acute) (viral)
Meningoencephalitis›virus NEC
Meningoencephalomyelitis›acute NEC(viral)

Questions about A86

Is A86 a billable ICD-10-CM code?: Yes. A86 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
Where does A86 sit in the tabular list?: Certain infectious and parasitic diseases (A00-B99), in the block Viral and prion infections of the central nervous system (A80-A89).