Personal history of latent tuberculosis infection

This code signifies that a patient has a past history of being infected with Mycobacterium tuberculosis, but the infection is currently inactive and not causing symptoms or disease. The bacteria remain dormant in the body, and the individual is not contagious.

Apply this code when a patient has a documented history of a positive tuberculosis skin test (TST) or interferon-gamma release assay (IGRA), but no evidence of active tuberculosis disease. This is often used for ongoing monitoring or when considering prophylactic treatment for reactivation.

• Do not use this code for active tuberculosis disease; refer to codes in the A15-A19 range.
• This code indicates a history of infection, not current active disease or exposure.
• Ensure documentation clearly states "latent" or "inactive" tuberculosis infection.