Is A85 a billable ICD-10-CM code?

No. A85 is a non-billable header code. Code to a higher level of specificity using one of its child codes.

Where does A85 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).

What cannot be coded together with A85?

A85 carries an Excludes1 note, which means the conditions it lists can never be coded together with it on the same encounter.

A85

A85 — Other viral encephalitis, not elsewhere classified

Non-billable headerICD-10-CM

A85 is a non-billable header ICD-10-CM code for other viral encephalitis, not elsewhere classified. It cannot be billed on its own: choose one of the more specific child codes below.

Excludes1 — never code together

These conditions cannot occur together. Billing both on the same encounter is a denial.

encephalitis due to cytomegalovirus (B25.8)
encephalitis due to herpesvirus NEC (B10.0-)
encephalitis due to herpesvirus [herpes simplex] (B00.4)
encephalitis due to measles virus (B05.0)
encephalitis due to mumps virus (B26.2)
encephalitis due to poliomyelitis virus (A80.-)
encephalitis due to zoster (B02.0)
lymphocytic choriomeningitis (A87.2)
myalgic encephalomyelitis (G93.32)

Includes

Conditions this code covers.

specified viral encephalomyelitis NEC
specified viral meningoencephalitis NEC

Other codes that can never be billed with A85

These codes carry an Excludes1 note pointing at A85. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading A85 alone.

G05Encephalitis, myelitis and encephalomyelitis in diseases classified elsewhere

Risk adjustment

A85 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.

Code to one of these instead A85

4 child codes. Green means billable.

Questions about A85

Is A85 a billable ICD-10-CM code?: No. A85 is a non-billable header code. Code to a higher level of specificity using one of its child codes.
Where does A85 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).
What cannot be coded together with A85?: A85 carries an Excludes1 note, which means the conditions it lists can never be coded together with it on the same encounter.