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A92.30 ICD-10-CM Code: West Nile virus infection, unspecified

Billing Status: YES. This is a valid, specific, and billable ICD-10-CM reference.

Coding at a Glance

Tabular directives
3 inclusion terms · 1 Excludes1

Inpatient Payment Groups (MS-DRG)

Potential MS-DRG participation — not a DRG assignment.

MS-DRGs this diagnosis helps define, as principal or secondary, per the CMS ICD-10-CM/PCS MS-DRG Definitions Manual v44, Appendix B.

A diagnosis appearing in a group's logic does not by itself determine the DRG assigned to a stay; the grouper uses the full claim.

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for A92.30 in the official ICD-10-CM tabular list, quoted as published.

Source: CMS/CDC — ICD-10-CM Tabular ListRelease: FY2027Effective: October 1, 2026

Trace:FY2027 changesChange historyRelease, file and checksum

Notes without a marker are published on A92.30 itself; “inherited from” names the category or block whose note applies here.

Inclusion Terms

Alternative terms the tabular list files under this code.

  • West Nile fever NOS
  • West Nile fever without complications
  • West Nile virus NOS

Excludes1 — Not Coded Here

Conditions generally not reported together with this code (Excludes1) -- an error unless the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).

Source: inherited from A92

Coder workflow for A92.30

MedCoder structured workflow — derived from this code’s own official record

Before you code A92.30

  1. Unspecified does not mean incorrect. When the record gives no greater specificity, A92.30 may be the appropriate code. Check the record for detail that supports a more specific sibling — in this subcategory the siblings differ by the presence or absence of the associated condition. An unspecified code is for records that do not provide the detail a more specific code needs; a query, not an assumption, is the route to specificity (Guidelines I.A.9.b, I.B.18).

    ReviewA92.31, A92.32, A92.39

    See the relationships section · Guide: Other vs unspecified (NEC vs NOS) →

  2. Check the Excludes1 note: if the documentation supports a condition named there, do not simply proceed with A92.30. Excludes1 conditions are not reported together with this code unless the record shows they are unrelated (Guidelines I.A.12.a).

    See the official tabular notes

Choose the right path

  1. Does the record document the detail a more specific sibling code needs?
    Yes → Review the specific siblings in this subcategory.
    No → Continue — A92.30 is appropriate when the documentation goes no further.

    ReviewA92.31, A92.32, A92.39

  2. Does the documentation support a condition named in A92.30’s Excludes1 note?
    Yes → Do not simply proceed: review the excluded code. Both are reported only when the record shows the two conditions are unrelated.
    No → Continue.

    ReviewB33.1

Consider A92.30. Then confirm the code is valid for the date of service in the Verify section.

Documentation check

The provider’s diagnostic statement
Codes are assigned from the provider’s documented diagnosis, not from clinical criteria, test values or a medication list (Guidelines I.A.19).
The associated condition or complication
Whether the associated condition the title names is documented; the “with” convention presumes some links, and a provider statement that the conditions are unrelated defeats it (Guidelines I.A.15).
Any detail beyond this code’s title
What the record states that a more specific sibling code would capture — or its absence, which itself supports the unspecified code.

Official instructions as workflow

  • Excludes1 — check before selecting A92.30(1 note)

    Coding workflow: If the documentation supports a condition named in this note, do not simply proceed with A92.30: the two are not reported together. The one exception is when the record shows the two conditions are unrelated to each other.

    CompareB33.1

    See the official tabular notes · Guidelines I.A.12.a

Coding decision scenarios

Pattern scenarios for this code’s structure — decision rules, not clinical cases

Documentation: The provider documents the condition in the terms of this code’s title and records no further detail.

Coding question: Is a more specific sibling code supportable?

Path: Review the specific siblings in this subcategory and what each requires the record to state.

Reason: A more specific code needs documentation of the distinguishing element; without it the unspecified code is appropriate, and a provider query is the route to specificity (Guidelines I.A.9.b, I.B.18).

ReviewA92.31, A92.32, A92.39

Documentation: Both the condition A92.30 describes and a condition named in its Excludes1 note are documented for the same encounter.

Coding question: Can both codes be reported?

Path: Review the Excludes1 note and the excluded code, and look for a provider statement on whether the two conditions are related.

Reason: Excludes1 means the two are not coded together; the exception is when the record shows the conditions are unrelated to each other (Guidelines I.A.12.a).

ReviewB33.1

Every row is derived from this code’s own record — its title, tabular notes, 7th-character family and same-category siblings — with fixed MedCoder wording; nothing is inferred about a patient. The official notes and guideline text are in the sections each row links to, and they control.

Don’t confuse A92.30 with…

MedCoder analysis — pairs from this code’s official notes, distinctions written by MedCoder

The codes most likely to be picked instead of A92.30 — named in its own official notes, or sharing its laterality or encounter family — with what separates them and which documentation moves the case. Each links to the full comparison.

  • B33.1— Excludes1 conflict (Excludes1 — generally not reported together)

    Not coded here — the tabular list excludes this pair for the same encounter.

    Not reported together with this code, except where the two conditions are documented as unrelated.

    What moves you there: Documentation of Ross River disease moves the case to B33.1; the two are not reported together unless documented as unrelated.

    Full comparison: A92.30 vs B33.1 →

Relationships are read from this code's own official notes, its laterality siblings and its encounter family; the wording of each distinction is MedCoder editorial, and the documentation named in each “what moves you there” line is the official note phrase or sibling title itself. Source: CMS ICD-10-CM tabular instructional notes; ICD-10-CM Official Guidelines, Section I.A.12.a.

Code Overview

West Nile virus infection, unspecified is a billable ICD-10-CM diagnosis code (A92.30).

MedCoder summary Summary composed by MedCoder from this code's official ICD-10-CM record. The tabular instructional notes themselves appear verbatim below.

Indexed Clinical Terms (2)

Official source data — entries quoted as published, in the Index’s own lookup phrasing

Clinical term phrases from the official ICD-10-CM Index to Diseases and Injuries that map to this code. These are alphabetic-index entries shown as the Index writes them — lookup phrasing, not necessarily the wording of a final diagnosis.

Verify Before Coding

  • MCC as a secondary diagnosis (FY2027). Can raise the stay's MS-DRG severity tier.

From the code registry, the Medicare Code Editor, and the MS-DRG Definitions Manual. Check it against a full claim in Claim Check.

Relationships & Classification

MedCoder structured relationships — computed from published CMS and AHRQ datasets

Other codes that name A92.30 or its code family, from the CMS ICD-10-CM tabular instructional notes. Tabular-note edges are stored at the code family level that carries each note.

Referenced by 1 Excludes2 note: A83 — Mosquito-borne viral encephalitis (via A92.3.-).

These codes’ tabular lists name this diagnosis as distinct — both may be reported when both are documented.

MS-DRG Grouper Relationships (FY2027)

Potential MS-DRG participation — not a DRG assignment.

FY2027 MS-DRG: MCC — Major Complication or Comorbidity. Reported as a secondary diagnosis, this code raises the stay's MS-DRG severity tier — except when the principal diagnosis is one of 131 clinically related codes on its CMS exclusion list.

Named in the grouper logic of 2 MS-DRGs: DRG 865 (MDC 18), DRG 866 (MDC 18).

From the CMS MS-DRG Definitions Manual (Appendices B and C). Actual DRG assignment depends on the complete claim.

Clinical classification (AHRQ CCSR):INF008 — Viral infection (default).

Clinical Classifications Software Refined (CCSR) for ICD-10-CM Diagnoses. Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality.

Related Codes

Same clinical process (MS-DRG)

Acts as MCC — raises the severity of other admissions. CMS groups these diagnoses into one MS-DRG principal-diagnosis exclusion process — a CC/MCC on this list never raises severity when the principal diagnosis is also on it.

A85.1 — Adenoviral encephalitis, A85.2 — Arthropod-borne viral encephalitis, unspecified, A85.8 — Other specified viral encephalitis, A87.2 — Lymphocytic choriomeningitis, A88.0 — Enteroviral exanthematous fever [Boston exanthem], A88.8 — Other specified viral infections of central nervous system, A91 — Dengue hemorrhagic fever, A92.0 — Chikungunya virus disease, A92.1 — O'nyong-nyong fever, A92.2 — Venezuelan equine fever, A92.4 — Rift Valley fever, A92.5 — Zika virus disease, A92.8 — Other specified mosquito-borne viral fevers, A92.9 — Mosquito-borne viral fever, unspecified, A93.0 — Oropouche virus disease, A93.1 — Sandfly fever, A93.2 — Colorado tick fever, A93.8 — Other specified arthropod-borne viral fevers, A94 — Unspecified arthropod-borne viral fever, A98.0 — Crimean-Congo hemorrhagic fever, +110 more

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical category (Viral infection).

+309 more

Same Index main term, other category

The ICD-10-CM Index to Diseases and Injuries files this code under the main term “Fever”; these codes share that main term but sit in a different category of the Tabular List.

A77.49 — Other ehrlichiosis (spotted, Ehrlichiosis, due to, specified organism NEC), A77.8 — Other spotted fevers (African tick bite), A77.9 — Spotted fever, unspecified (spotted), A78 — Q fever (Q), A79.0 — Trench fever (Meuse), A79.1 — Rickettsialpox due to Rickettsia akari (Kew Garden), A80.4 — Acute nonparalytic poliomyelitis (polioviral), A88.0 — Enteroviral exanthematous fever [Boston exanthem] (enteroviral exanthematous), A90 — Dengue fever [classical dengue] (sun), A91 — Dengue hemorrhagic fever (Bangkok hemorrhagic), A93.0 — Oropouche virus disease (Oropouche), A93.1 — Sandfly fever (Chitral), A93.2 — Colorado tick fever (Colorado tick), A93.8 — Other specified arthropod-borne viral fevers (Piry), A94 — Unspecified arthropod-borne viral fever (hemorrhagic NOS), A95.0 — Sylvatic yellow fever (yellow, jungle), A95.1 — Urban yellow fever (yellow, urban), A95.9 — Yellow fever, unspecified (yellow), A96.0 — Junin hemorrhagic fever (Juninhemorrhagic), A96.1 — Machupo hemorrhagic fever (Machupohemorrhagic), +108 more

Contextual Map

Every relationship of A92.30 in one view: hierarchy, official tabular instructions in both directions, clinical classification, risk adjustment, MS-DRG participation, index terms and change history — each edge carrying the CMS source it derives from.

Run A92.30 with this related code in Claim Check

Hierarchy

Referenced by Excludes2 notes

Clinical classification (CCSR)

MS-DRG Grouper

  • MCC — Major Complication or Comorbidity [MS-DRG severity]: “As a secondary diagnosis this code can raise the stay's MS-DRG severity tier (MCC).”— CMS MS-DRG Definitions Manual (Appendix C) · FY2027
  • DRG 865 — VIRAL ILLNESS WITH MCC[MS-DRG]: “VIRAL ILLNESS WITH MCC (MDC 18)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2027
  • DRG 866 — VIRAL ILLNESS WITHOUT MCC[MS-DRG]: “VIRAL ILLNESS WITHOUT MCC (MDC 18)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2027

MDC crossing

  • MDC 18 — Infectious and Parasitic Diseases, Systemic or Unspecified Sites[MDC crossing]: “Infectious and Parasitic Diseases, Systemic or Unspecified Sites — the grouper's crossing between diagnoses and procedures: a principal diagnosis sets the MDC, and same-MDC procedures move the stay to its surgical DRGs. 1 same-MDC procedures group here; browse them on the MDC page.”— CMS MS-DRG Definitions Manual · FY2027

Index entries

  • Fever (inanition) (of unknown origin) (persistent) (with chills) (with rigor), West, Nile (viral)[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027
  • Virus, viral, West Nile (fever)[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027

Nearest codes (12)

Change history

  • FY2016 — In the code set at ICD-10-CM adoption [Change history]— CMS release files (code change ledger) · icd10cm-fy2016

Sources for this page

Codes, titles, notes, index terms and mappings on this page are transcribed from the datasets below. Relationships MedCoder computed and text MedCoder wrote are labelled where they appear.

Code, title, tabular notes and index terms Official source data
CMS/CDC ICD-10-CM FY2027 tabular list, index and tables, effective October 1, 2026 Release, file and checksum · Publisher’s page
Claim edits Official source data
CMS Definitions of Medicare Code Edits — v44.0 (October 2026) Release, file and checksum · Publisher’s page
Inpatient payment groups Official source data
CMS MS-DRG Definitions Manual (incl. Appendix B diagnosis index, Appendix C CC/MCC list, Appendix E procedure index) and IPPS Final Rule tables — v44 Release, file and checksum · Publisher’s page
Change history and date-of-service validity Official source data
CMS ICD-10-CM release addenda, ingested release by release into the change ledger Release, file and checksum · Publisher’s page
Comparisons, relationships and the contextual map MedCoder structured relationship
Computed by MedCoder from the tabular notes and tables above; every derived relationship is marked as derived where it appears
Summary and FAQ answers MedCoder explanation
Written by MedCoder to explain the sources above: drafted with AI assistance, checked by a person against the release files, and labelled as MedCoder text where it appears. Not official text.

Labels on this page: Official source data · MedCoder structured relationship · MedCoder explanation. How to read the labels · All data sources and release dates

Cite this page

Reference this page in a research guide, syllabus or article. The release is included because code content changes each year.

MedCoder.ai. "A92.30 — West Nile virus infection, unspecified." ICD-10-CM FY2027. https://medcoder.ai/icd10/code/a92.30-west-nile-virus-infection-unspecified

Change history

  • FY2016 — October 1, 2015
    In the code set at ICD-10-CM adoption
    West Nile virus infection, unspecified

No changes since FY2016 — additions, deletions, description changes and billable-status changes are tracked through FY2027, and none are recorded for this code. Note changes are tracked from FY2027 only.

Nearest Codes in This Family

Official ICD-10-CM classifications closest to A92.30 in its code family, with their registry titles.

View all codes in the A92 family