2026 ICD-10-CM Diagnosis Code B97.35Human immunodeficiency virus, type 2 [HIV 2] as the cause of diseases classified elsewhere

ICD-10-CM Codes›A00–B99›B95-B97›B97

ICD-10-CM B97.35
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

B97.35 is a billable ICD-10-CM diagnosis code for human immunodeficiency virus, type 2 [HIV 2] as the cause of diseases classified elsewhere. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 865 through 866. The code is not accepted as a principal diagnosis by the Medicare Code Editor. Coders also document this condition as encephalitis caused by human immunodeficiency virus type 2. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under HIV infection.

Code Identity

ICD-10-CM Code
B97.35
Billable Status
Yes — Valid for Submission
Code Describes
Human immunodeficiency virus, type 2 [HIV 2] as the cause of diseases classified elsewhere
Short Description
HIV 2 as the cause of diseases classified elsewhere
Parent Code
B97.3
Retrovirus as the cause of diseases classified elsewhere

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionB95-B97Bacterial and viral infectious agents
CategoryB97Viral agents as the cause of diseases classified elsewhere
This CodeB97.35Human immunodeficiency virus, type 2 [HIV 2] as the cause of diseases classified elsewhere

Code EditsBilling

Medicare Code Editor checks that affect claim validity for B97.35.

Unacceptable principal diagnosis
There are selected codes that describe a circumstance which influences an individual's health status but not a current illness or injury, or codes that are not specific manifestations but may be due to an underlying cause. These codes are considered unacceptable as a principal diagnosis.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Encephalitis caused by human immunodeficiency virus type 2
  • Human immunodeficiency virus encephalitis
  • Human immunodeficiency virus II infection
  • Retroviridae encephalitis

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Human
      • immunodeficiency virus (HIV) disease (infection)
        • type-2 (HIV 2) as cause of disease classified elsewhere
    • Infection, infected, infective(opportunistic)
      • retrovirus
        • as cause of disease classified elsewhere
          • human
            • immunodeficiency, type 2 (HIV 2)
    • Infection, infected, infective(opportunistic)
      • virus, viral NOS
        • as cause of disease classified elsewhere
          • human
            • immunodeficiency, type 2 (HIV 2)
    • Infection, infected, infective(opportunistic)
      • virus, viral NOS
        • as cause of disease classified elsewhere
          • retrovirus
            • human
              • immunodeficiency, type 2 (HIV 2)
    • Retrovirus, as cause of disease classified elsewhere
      • human
        • immunodeficiency, type 2 (HIV 2)

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR INF006
HIV infection
Default principal diagnosis: inpatient No · outpatient No

Patient EducationClinical

HIV

HIV stands for human immunodeficiency virus. HIV harms your immune system by destroying a type of white blood cell that helps your body fight infection. This puts you at risk for other infections and diseases.

The full article covers:

  • What is HIV?
  • What is AIDS?
  • How does HIV spread?
  • Who is at risk for HIV infection?
  • What are the symptoms of HIV?
  • How do I know if I have HIV?
  • What are the treatments for HIV?
  • Can HIV infection be prevented?

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert B97.35 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
079.53 Hiv-2 infection oth dis
Exact Match The mapping is direct, with no qualifiers.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About B97.35Overview

Is B97.35 (Retrovirus as the cause of diseases classified elsewhere) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report human immunodeficiency virus, type 2 [HIV 2] as the cause of diseases classified elsewhere on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does B97.35 group to?

On inpatient claims, human immunodeficiency virus, type 2 [HIV 2] as the cause of diseases classified elsewhere maps to MS-DRG 865, 866, with relative weights from 0.8696 to 1.4983 depending on complications. Higher weights mean higher Medicare reimbursement.

Can B97.35 be a principal diagnosis?

No. The Medicare Code Editor rejects this code as a principal diagnosis because human immunodeficiency virus, type 2 [HIV 2] as the cause of diseases classified elsewhere describes a circumstance that influences health status rather than a current illness. Report it as a secondary diagnosis.

What is the ICD-9 equivalent of B97.35?

Under the General Equivalence Mappings, human immunodeficiency virus, type 2 [HIV 2] as the cause of diseases classified elsewhere converts to ICD-9-CM 079.53 (Hiv-2 infection oth dis). The mapping is a direct match.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.