ICD-10 Code C34 – Malignant neoplasm of bronchus and lung (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C34 – Malignant neoplasm of bronchus and lung
What it is
C34 identifies a malignant tumor arising in the bronchus or lung. Use it when the record documents primary lung cancer, not metastatic disease.
Clinical signs
Clinical features vary; refer to documentation. Commonly recorded findings include cough, hemoptysis, chest pain, dyspnea, or imaging showing a suspicious pulmonary mass.
When to use this code
Use C34 when the provider diagnoses a primary malignant neoplasm of the bronchus or lung. Apply the most specific subcategory available if the note identifies lobe, main bronchus, or laterality. If the site is unclear, check documentation before assigning a code.
Do not use for
Do not use C34 for metastatic tumors to the lung or for benign pulmonary nodules. Do not assign it when the documentation only states “lung mass” without a confirmed malignant diagnosis.
Coding tip
Look for the exact anatomic site and whether the neoplasm is primary or secondary before coding.