ICD-10 Code D80.3 – Selective deficiency of immunoglobulin G [IgG] subclasses (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code D80.3 – Selective deficiency of immunoglobulin G [IgG] subclasses
What it is
D80.3 identifies a selective deficiency of one or more IgG subclasses. Use it when documentation shows an immunoglobulin subclass deficiency rather than a broad antibody disorder.
Clinical signs
Clinical features vary; refer to documentation. Commonly noted findings include recurrent sinopulmonary infections and evidence of reduced IgG subclass levels with otherwise preserved total immunoglobulin results.
When to use this code
Use D80.3 when the provider documents selective IgG subclass deficiency, IgG subclass deficiency, or a similar confirmed diagnosis. It may apply after immunology workup supports the subtype and the record does not describe a different primary immunodeficiency.
If the note only mentions recurrent infections or abnormal immune testing without a clear diagnosis, check documentation before coding. Code the confirmed condition, not the suspicion or the test result alone.
Do not use for
Do not use this code for unspecified hypogammaglobulinemia, common variable immunodeficiency, or isolated low total IgG. Check documentation when the chart uses broader immune deficiency language.
Coding tip
Code D80.3 only when the subclass deficiency is explicitly documented; if the record is vague, query for the specific immune diagnosis.