D80.3
BillableSelective deficiency of immunoglobulin G [IgG] subclasses
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is D80.3 an HCC code?
Yes. D80.3 maps to Specified Immunodeficiencies and White Blood Cell Disorders under the CMS-HCC V28 risk adjustment model (and Disorders of Immunity 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.
MEAT Criteria for D80.3
For D80.3to 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 D80.3 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
D80.3 is the ICD-10-CM diagnosis code for selective deficiency of immunoglobulin g [igg] subclasses. A condition where the body has abnormally low levels of specific subtypes of IgG antibodies. D80.3 sits in the ICD-10-CM chapter for diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism (d50-d89), within the section covering certain disorders involving the immune mechanism (d80-d89).
Under the CMS-HCC V28 risk adjustment model, D80.3 maps to Specified Immunodeficiencies and White Blood Cell Disorders (HCC 115) with a community, non-dual, aged base RAF weight of 0.565. Under the older CMS-HCC V24 model, D80.3 maps to Disorders of Immunity (HCC 47) with a community, non-dual, aged base RAF weight of 0.665. 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.
Specify which IgG subclass is deficient if documented (IgG1, IgG2, IgG3, or IgG4). Because D80.3 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 D80.3 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Specify which IgG subclass is deficient if documented (IgG1, IgG2, IgG3, or IgG4)
- •Document clinical manifestations such as recurrent infections or autoimmune features
Clinical Significance
Selective immunoglobulin G subclass deficiency involves low levels of one or more of the four Immunoglobulin G subclasses (Immunoglobulin G1 through Immunoglobulin G4) while total Immunoglobulin G may remain normal. Immunoglobulin G2 subclass deficiency is most clinically significant as it impairs defense against polysaccharide-encapsulated bacteria, leading to recurrent sinopulmonary infections, while Immunoglobulin G4 deficiency is often clinically insignificant.
Documentation Requirements
- ✓Documentation should specify which Immunoglobulin G subclass is deficient (Immunoglobulin G1, G2, G3, or G4), include quantitative subclass levels compared to age-appropriate reference ranges, total Immunoglobulin G level, clinical manifestations (recurrent infections, their type and frequency), and response to vaccination challenge testing.
- ✓Document treatment with immunoglobulin replacement if applicable.
Commonly Confused Codes
- •D80.2 (selective Immunoglobulin A deficiency which affects a different immunoglobulin class), D80.0 (hereditary hypogammaglobulinemia with pan-hypogammaglobulinemia), D80.1 (nonfamilial hypogammaglobulinemia where all immunoglobulins are low), D83.0 (common variable immunodeficiency with B-cell abnormalities, a distinct entity).