ICD-10 Code A31.0 – Pulmonary mycobacterial infection (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code A31.0 – Pulmonary mycobacterial infection
What it is
This code identifies a mycobacterial infection involving the lungs. It is used when documentation specifies pulmonary disease caused by mycobacteria, including non-tuberculous organisms.
Clinical signs
Clinical features vary; refer to documentation. Commonly reported findings include chronic cough, sputum production, weight loss, fatigue, and radiographic lung abnormalities consistent with mycobacterial infection.
When to use this code
Use A31.0 when the provider documents pulmonary mycobacterial infection, pulmonary mycobacteriosis, or similar wording tied to lung involvement. Code it when the diagnosis is confirmed or clearly assessed in the record. If the note only says “mycobacterial infection” without site, check documentation.
Do not use for
Do not use this code for tuberculosis or for mycobacterial infection limited to a nonpulmonary site. If the organism or anatomic site is unclear, check documentation before assigning the code.
Coding tip
Confirm that the record specifies pulmonary involvement; site matters for correct code selection.