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
MappedHCC 1
Varies by metal level
ESRD/PACE
MappedHCC 1
RAF 0.122
RXHCC
MappedHCC 1
RAF 8.523
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
Current with CMS: FY2026 ICD-10-CM Apr 1 update (effective Apr 1 – Sep 30, 2026) · CMS-HCC V28, 100% phased in for payment year 2026. FY2027 code set already staged for October 1, 2026. How HCC Buddy stays current →
Is B20 an HCC code?
Yes. B20 (Human immunodeficiency virus [HIV] disease) maps to HIV/AIDS under the CMS-HCC V28 risk adjustment model (and HIV/AIDS under V24), with a community non-dual aged RAF of 0.301. It is billable for payment year 2026.
Coder answer: B20 is billable and maps to V28 HCC 1, HIV/AIDS. Open it in the Code Book for the tabular path, RAF, and MEAT checklist.
- Code
- B20
- Description
- Human immunodeficiency virus [HIV] disease
- HCC (V28)
- HCC 1 — HIV/AIDS
- RAF
- 0.301
- Billable
- Yes
- Payment year
- 2026
HCC Category Mapping
Each model's RAF is its CMS base weight for that model's standard population, so weights are not directly comparable across models: CMS-HCC V28 and V24 use Community, Non-Dual, Aged; ESRD uses the dialysis continuing-enrollee model; RxHCC is the Part D continuing-enrollee, non-low-income, aged weight (a larger scale than CMS-HCC). ACA/HHS has no single weight — it varies by metal level. 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 B20 to 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.
Human immunodeficiency virus disease, HIV infection with any clinical manifestation or AIDS-defining condition. Per ICD-10-CM convention, B20 is used for confirmed HIV disease with any clinical evidence of immunodeficiency. 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
- •Human immunodeficiency virus disease, HIV infection with any clinical manifestation or AIDS-defining condition. Per ICD-10-CM convention, B20 is used for confirmed HIV disease with any clinical evidence of immunodeficiency.
- •Do not use B20 for asymptomatic HIV (use Z21). The distinction hinges on clinical manifestations, opportunistic infections, AIDS-defining illness, or provider-documented HIV disease all support B20.
- •V28 HCC 1 (HIV/AIDS) at RAF 0.301. HIV disease is durable HCC coding; once B20 is appropriate, the patient continues to qualify even during well-controlled therapy.
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