ICD-10 Code J43.0 – Unilateral pulmonary emphysema [MacLeod’s syndrome] (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code J43.0 – Unilateral pulmonary emphysema [MacLeod’s syndrome]
What it is
J43.0 identifies unilateral pulmonary emphysema, also called MacLeod’s syndrome. It describes abnormal overexpansion and air trapping in one lung, usually from postinfectious or developmental changes.
Clinical signs
Findings may include reduced breath sounds on one side, hyperinflation, and decreased perfusion of the affected lung. Clinical features vary; refer to documentation.
When to use this code
Use J43.0 when the provider documents unilateral pulmonary emphysema or MacLeod’s syndrome. It is appropriate when imaging or specialist notes support one-sided emphysematous change rather than generalized COPD. Check documentation if the record only says emphysema without laterality.
Do not use for
Do not use J43.0 for nonspecific emphysema, bilateral emphysema, or other chronic obstructive lung disease without unilateral involvement. Do not assign it when MacLeod’s syndrome is not documented.
Coding tip
Code the condition only when the unilateral nature is clearly stated in the record.