ICD-10 A85
Non-Billable HeaderOther viral encephalitis, not elsewhere classified
About ICD-10-CM A85
ICD-10-CM code A85 represents Other viral encephalitis, not elsewhere classified. This is a non-billable header code in the Infectious and Parasitic Diseases chapter (block A85). The 2026 edition of ICD-10-CM A85 became effective on October 1, 2025. Non-billable codes cannot be used as a primary or secondary diagnosis on a claim, use a more specific child code instead.
Type 1 Excludes
Pure excludes, these codes can never be coded together with A85. The conditions are mutually exclusive (e.g., congenital vs acquired forms).
- 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
- specified viral encephalomyelitis NEC
- specified viral meningoencephalitis NEC
Medicare LCD Coverage for A85
Local Coverage Determinations (LCDs) from CMS MACs that list A85 as a covered diagnosis.
This doesn't mean the code isn't covered, it means no MAC has issued a Local Coverage Determination naming this specific code. Coverage may still apply under National Coverage Determinations or general medical-necessity rules.
Commercial Payer Coverage
Coverage policies from major commercial payers referencing A85.
Our payer policy database covers Aetna, Cigna, Anthem, BCBS, Humana, and Medicare Advantage plans, but A85 doesn't currently appear in any indexed policy. The code may still be covered under standard plan benefits.
CPT Codes Commonly Billed with A85
Procedures frequently paired with this diagnosis based on PayerReady's Dx↔Px linkage data.
We don't have CPT pairings indexed for this specific code yet. Use the CPT search above to find common procedures, or check your payer's published medical policy for code-specific guidance.
Codes Adjacent To A85
Other codes in section A80-A89 (Viral and prion infections of the central nervous system).
ICD-10 A85, Billing FAQ
Is ICD-10 code A85 billable? +
No, A85 is a non-billable header code. Use a more specific child code from block A85 when submitting claims.
What codes are Type 1 Excludes for A85? +
Type 1 Excludes (never code together with A85): encephalitis due to cytomegalovirus (B25.8); encephalitis due to herpesvirus NEC (B10.0-); encephalitis due to herpesvirus [herpes simplex] (B00.4)
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Reviewed by the PayerReady Medical Coding Team
Verified against the CMS 2026 code set on May 31, 2026.
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