ICD-10 Code C34.8 – Malignant neoplasm of overlapping sites of bronchus and lung (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C34.8 – Malignant neoplasm of overlapping sites of bronchus and lung
What it is
C34.8 identifies a malignant tumor that involves overlapping sites of the bronchus and lung, meaning the exact primary location cannot be assigned to one specific lobe or bronchial site. Use it when documentation clearly states overlapping involvement.
Clinical signs
Clinical features vary; refer to documentation. Common findings in lung cancer may include cough, hemoptysis, chest pain, dyspnea, or imaging showing a mass with spread across adjacent bronchopulmonary sites.
When to use this code
Use C34.8 when the provider documents a primary malignant neoplasm involving overlapping sites of the bronchus and lung. It is appropriate when the record does not support a more specific anatomic lung or bronchial code. Check documentation if the tumor site is described only as lung cancer without overlap.
Do not use for
Do not use this code for metastatic disease to the lung, secondary malignant neoplasms, or benign pulmonary lesions. Avoid it when the primary site is known and a more specific C34 code applies.
Coding tip
Code the documented primary site exactly; if overlap is not stated, choose the most specific confirmed bronchus or lung code.