B20 ICD-10-CM Code: Human immunodeficiency virus [HIV] disease
HCC Buddy Code Card
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FY 2026 Apr update / Certain infectious and parasitic diseases (A00-B99) / Human immunodeficiency virus [HIV] disease (B20)
B20
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceHuman immunodeficiency virus [HIV] disease
This code represents a diagnosis of HIV (human immunodeficiency virus) disease, which is a viral infection that attacks the immune system and can progress to AIDS if untreated. It is used to document that a patient has been diagnosed with HIV infection.
Buddy Insight
Human immunodeficiency virus disease is one of the most significant codes in risk adjustment, carrying its own dedicated HCC category (HCC 1) across all models.
CMS-HCC V28
MappedHCC 1
RAF 0.301
CMS-HCC V24
MappedHCC 1
RAF 0.335
ACA/HHS
00
RAF 0
ESRD/PACE
MappedHCC 1
RAF 0.0
RXHCC
MappedHCC 1
RAF 0.0
Code Trumping
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Code Book Path
Inclusion Terms
OfficialICD-10-CM does not list inclusion terms for B20 in this effective period.
Excludes 2
OfficialICD-10-CM does not list Excludes 2 notes for B20 in this effective period.
Related Child Codes
ICD-10-CM does not list child codes under B20 for this display context.
Includes
Official- acquired immune deficiency syndrome [AIDS]
- AIDS-related complex [ARC]
- HIV infection, symptomatic
Excludes 1
Official- asymptomatic human immunodeficiency virus [HIV] infection status (Z21)
- exposure to HIV virus (Z20.6)
- inconclusive serologic evidence of HIV (R75)
Code First
Official- Human immunodeficiency virus [HIV] disease complicating pregnancy, childbirth and the puerperium, if applicable (O98.7-)
Use Additional
Official- code(s) to identify all manifestations of HIV infection
Code Also
OfficialICD-10-CM does not list Code Also instructions for B20 in this effective period.
Buddy Documentation Tip
MEAT Support
Audit Caution
Common Mistakes
Last updated: FY2026 ICD-10-CM Apr update, Apr 1, 2026 through Sep 30, 2026. CMS-HCC V28 is 100% phased in for payment year 2026.
Is B20 an HCC code?
Yes. B20 maps to HIV/AIDS under the CMS-HCC V28 risk adjustment model (and HIV/AIDS under V24).
HCC Category Mapping
RAF weights shown are the community, non-dual, aged base weights from the CMS risk adjustment model file. Actual per-patient RAF contribution depends on member segment, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains in use during the transition and for historical data.
Work B20 in the Code Book — tabular path, V28 RAF, and MEAT checklist →
MEAT Criteria for B20
For B20to count as a valid HCC diagnosis in a given encounter, the provider's documentation must show MEAT: Monitor, Evaluate, Assess, or Treat. A diagnosis from a prior year does not carry forward automatically, it has to be re-documented and supported each calendar year.
- MMonitor: signs, symptoms, disease progression, or lab trending documented in the note
- EEvaluate: test results, medication response, or physical findings reviewed by the provider
- AAssess: explicit mention in the assessment or plan with acknowledgment of status
- TTreat: medication, referral, procedure, therapy, or counseling tied to the diagnosis
Only one of M/E/A/T is required to support the code, but the documentation must be specific enough to show that the provider actually addressed B20 during that encounter, not just copy-forwarded from a problem list.
Coder workflow notes
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What This Code Means
B20 is the ICD-10-CM diagnosis code for human immunodeficiency virus [hiv] disease. This code represents a diagnosis of HIV (human immunodeficiency virus) disease, which is a viral infection that attacks the immune system and can progress to AIDS if untreated. It is used to document that a patient has been diagnosed with HIV infection. B20 sits in the ICD-10-CM chapter for certain infectious and parasitic diseases (a00-b99), within the section covering human immunodeficiency virus [hiv] disease (b20).
Under the CMS-HCC V28 risk adjustment model, B20 maps to HIV/AIDS (HCC 1) with a community, non-dual, aged base RAF weight of 0.301. Under the older V24 model, B20 mapped to the same category but with a base RAF weight of 0.335, V28 recalibrated weights across the entire model. V28 is the CMS-HCC risk adjustment model that reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition.
B20 is the parent code for HIV disease; always use a more specific code from the B20 subcategories that indicates the stage of disease or associated conditions (such as B20.0 for HIV with mycobacterial infection, B20.1 for HIV with other bacterial infections, etc.). Because B20 maps to a payment HCC, the provider's documentation must satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's Medicare Advantage risk adjustment score. When documentation is ambiguous, coders should issue a provider query rather than assume the highest-specificity variant.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for B20 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •B20 is the parent code for HIV disease; always use a more specific code from the B20 subcategories that indicates the stage of disease or associated conditions (such as B20.0 for HIV with mycobacterial infection, B20.1 for HIV with other bacterial infections, etc.)
- •Do not use B20 alone in current coding practice; verify that a fifth character or additional specificity is documented regarding opportunistic infections, CD4 count status, or other HIV-related conditions to ensure accurate and complete coding
Clinical Significance
Human immunodeficiency virus disease is one of the most significant codes in risk adjustment, carrying its own dedicated HCC category (HCC 1) across all models. HIV disease requires lifelong antiretroviral therapy and monitoring, with substantial healthcare resource utilization. Accurate annual capture is essential as it must be reported each calendar year.
Documentation Requirements
- ✓Confirmed HIV diagnosis (positive HIV-1/2 antibody/antigen combination test with confirmatory testing)
- ✓CD4 count and viral load (HIV RNA quantitative) from current year
- ✓Current antiretroviral therapy regimen documented
- ✓Associated conditions: opportunistic infections, AIDS-defining illnesses
- ✓Provider assessment and plan addressing HIV management in current encounter
Includes
- acquired immune deficiency syndrome [AIDS]
- AIDS-related complex [ARC]
- HIV infection, symptomatic
Excludes 1, Do NOT code together
Use Additional Code
- code(s) to identify all manifestations of HIV infection
Code First
- Human immunodeficiency virus [HIV] disease complicating pregnancy, childbirth and the puerperium, if applicable (O98.7-)
Commonly Confused Codes
- •Z21 (Asymptomatic human immunodeficiency virus infection status): Used for patients with positive HIV test but NO symptoms or manifestations; B20 indicates active HIV disease
- •R75 (Inconclusive laboratory evidence of HIV): Inconclusive testing; do not code B20 without confirmed positive result
- •Z20.6 (Contact with and suspected exposure to HIV): Exposure risk only, no confirmed infection