Combined immunity deficiency

This code represents a primary immunodeficiency disorder characterized by defects in both humoral (B-cell) and cellular (T-cell) immunity. Patients with combined immunity deficiency are highly susceptible to severe, recurrent, and opportunistic infections due to the compromised function of both arms of the adaptive immune system.

Use this code for patients diagnosed with conditions such as severe combined immunodeficiency (SCID) or other primary immunodeficiencies affecting both T-cell and B-cell function. Documentation should clearly state a diagnosis of combined immunodeficiency, often supported by laboratory findings showing deficiencies in both lymphocyte populations.

• Distinguish from isolated B-cell or T-cell deficiencies; this code requires impairment in both.
• Always review physician documentation for specific type of combined immunodeficiency, if specified, for potential more granular coding.
• Sequence as a primary diagnosis when it is the reason for the encounter or treatment.