ICD-10 A92.31
Billable / Specific MCCWest Nile virus infection with encephalitis
About ICD-10-CM A92.31
ICD-10-CM code A92.31 represents West Nile virus infection with encephalitis. This is a billable/specific code in the Infectious and Parasitic Diseases chapter (block A92). The 2026 edition of ICD-10-CM A92.31 became effective on October 1, 2025.
Coding Tips for A92.31
Specialist guidance from the PayerReady Medical Coding Team. Specificity warnings, HCC capture rules, sequencing notes.
A92.31 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.
Inclusion Terms / Approximate Synonyms
Clinical terms and conditions classified under A92.31. Per CMS ICD-10-CM Tabular 2026.
- West Nile encephalitis
- West Nile encephalomyelitis
Inpatient DRG Impact, MCC
codes West Nile virus infection with encephalitis. As a Major Complication/Comorbidity (MCC), this can shift the DRG assignment to a higher-weighted category, substantial reimbursement impact.
Medicare LCD Coverage for A92.31
Local Coverage Determinations (LCDs) from CMS MACs that list A92.31 as a covered diagnosis.
Showing top 10 of 64 total . Click a CPT for full coverage scope.
Commercial Payer Coverage
Coverage policies from major commercial payers referencing A92.31.
1 Cigna
4 Medicare
CPT Codes Commonly Billed with A92.31
Procedures frequently paired with this diagnosis based on PayerReady's Dx↔Px linkage data.
- 95708 CMS LCD: Billing and Coding: Special Electroencephalography CMS LCD
- 95721 CMS LCD: Billing and Coding: Special Electroencephalography CMS LCD
- 95719 CMS LCD: Billing and Coding: Special Electroencephalography CMS LCD
- 95813 CMS LCD: Billing and Coding: Special Electroencephalography CMS LCD
- 95822 CMS LCD: Billing and Coding: Special Electroencephalography CMS LCD
- 95717 CMS LCD: Billing and Coding: Special Electroencephalography CMS LCD
- 95812 CMS LCD: Billing and Coding: Special Electroencephalography CMS LCD
- 95700 CMS LCD: Billing and Coding: Special Electroencephalography CMS LCD
- 95705 CMS LCD: Billing and Coding: Special Electroencephalography CMS LCD
Convert A92.31 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 |
|---|---|---|
| A92.31 | 06641 | 00000 |
Flags format (5 digits): Approximate · No Map · Combination · Scenario · Choice List. Source: CMS 2017 GEMs (final version).
Codes Adjacent To A92.31
Other codes in section A90-A99 (Arthropod-borne viral fevers and viral hemorrhagic fevers).
ICD-10 A92.31, Billing FAQ
Is ICD-10 code A92.31 billable? +
Yes, A92.31 is a billable ICD-10-CM code that can appear as a primary or secondary diagnosis on claims.
What other names or terms map to A92.31? +
ICD-10 A92.31 includes: West Nile encephalitis; West Nile encephalomyelitis.
Is A92.31 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 A92.31? +
Procedures frequently paired with A92.31 include: 95708, 95721, 95719, 95813, 95822.
What ICD-9 codes does A92.31 map to? +
Per CMS GEMs, A92.31 maps to ICD-9 codes: 06641. 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 June 1, 2026.
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