ICD-10 A85.2
Billable / Specific MCCArthropod-borne viral encephalitis, unspecified
About ICD-10-CM A85.2
ICD-10-CM code A85.2 represents Arthropod-borne viral encephalitis, unspecified. This is a billable/specific code in the Infectious and Parasitic Diseases chapter (block A85). The 2026 edition of ICD-10-CM A85.2 became effective on October 1, 2025.
Coding Tips for A85.2
Specialist guidance from the PayerReady Medical Coding Team. Specificity warnings, HCC capture rules, sequencing notes.
A85.2 is designated MCC for MS-DRG grouping. On inpatient claims, this code can shift the DRG to the with-MCC variant when documented as a present-on-admission secondary diagnosis. Hospital CDI programs flag MCC opportunities during chart review. Failure to capture this code may leave 30 to 80 percent of the inpatient stay revenue unrealized.
Type 1 Excludes
Pure excludes, these codes can never be coded together with A85.2. The conditions are mutually exclusive (e.g., congenital vs acquired forms).
- West nile virus with encephalitis (A92.31)
Inpatient DRG Impact, MCC
codes Arthropod-borne viral encephalitis, unspecified. As a Major Complication/Comorbidity (MCC), this can shift the DRG assignment to a higher-weighted category, substantial reimbursement impact.
Medicare LCD Coverage for A85.2
Local Coverage Determinations (LCDs) from CMS MACs that list A85.2 as a covered diagnosis.
Showing top 10 of 599 total . Click a CPT for full coverage scope.
Commercial Payer Coverage
Coverage policies from major commercial payers referencing A85.2.
5 Medicare
CPT Codes Commonly Billed with A85.2
Procedures frequently paired with this diagnosis based on PayerReady's Dx↔Px linkage data.
- 95929 CMS LCD: Billing and Coding: Neurophysiology Evoked Potentials (NEPs) CMS LCD
- 92651 CMS LCD: Billing and Coding: Neurophysiology Evoked Potentials (NEPs) CMS LCD
- 92653 CMS LCD: Billing and Coding: Neurophysiology Evoked Potentials (NEPs) CMS LCD
- 95928 CMS LCD: Billing and Coding: Neurophysiology Evoked Potentials (NEPs) CMS LCD
- 95930 CMS LCD: Billing and Coding: Neurophysiology Evoked Potentials (NEPs) CMS LCD
- 92652 CMS LCD: Billing and Coding: Neurophysiology Evoked Potentials (NEPs) CMS LCD
- 95939 CMS LCD: Billing and Coding: Neurophysiology Evoked Potentials (NEPs) CMS LCD
- G2189 CMS LCD: Billing and Coding: CT of the Head CMS LCD
- G2194 CMS LCD: Billing and Coding: CT of the Head CMS LCD
- G2193 CMS LCD: Billing and Coding: CT of the Head CMS LCD
Convert A85.2 to ICD-9-CM
Per CMS General Equivalence Mappings (GEMs), useful for legacy data review and historical claim analysis.
| ICD-10 | ICD-9 | Mapping Flags |
|---|---|---|
| A85.2 | 064 | 00000 |
Flags format (5 digits): Approximate · No Map · Combination · Scenario · Choice List. Source: CMS 2017 GEMs (final version).
Codes Adjacent To A85.2
Other codes in section A80-A89 (Viral and prion infections of the central nervous system).
ICD-10 A85.2, Billing FAQ
Is ICD-10 code A85.2 billable? +
Yes, A85.2 is a billable ICD-10-CM code that can appear as a primary or secondary diagnosis on claims.
What codes are Type 1 Excludes for A85.2? +
Type 1 Excludes (never code together with A85.2): West nile virus with encephalitis (A92.31)
Is A85.2 a CC or MCC for inpatient DRG? +
Yes, this code is designated as MCC. Documenting as a secondary diagnosis on inpatient claims can shift the DRG to a higher-weighted category.
What CPT codes are commonly billed with A85.2? +
Procedures frequently paired with A85.2 include: 95929, 92651, 92653, 95928, 95930.
What ICD-9 codes does A85.2 map to? +
Per CMS GEMs, A85.2 maps to ICD-9 codes: 064. Useful for legacy data review and historical claim analysis.
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Reviewed by the PayerReady Medical Coding Team
Verified against the CMS 2026 code set on July 16, 2026.
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