2026 ICD-10-CM Diagnosis Code C34.12Malignant neoplasm of upper lobe, left bronchus or lung
ICD-10-CM Codes›C00–D49›C30-C39›C34
- Billable — Valid for Submission
- Chronic Condition
C34.12 is a billable ICD-10-CM diagnosis code for malignant neoplasm of upper lobe, left bronchus or lung. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 180 through 182. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Respiratory cancers.
Code Identity
Code Classification
Quality Payment Program MeasuresBilling
Medicare quality measures that can apply when C34.12 is part of the patient record.
Lung Cancer Reporting (Biopsy/Cytology Specimens)
High Priority: YES
Measure Type: Process
Submission Methods: Claims, Registry
Description: Pathology reports based on lung biopsy and/or cytology specimens with a diagnosis of primary non-small cell lung cancer classified into specific histologic type following the International Association for the Study of Lung Cancer (IASLC) guidance or classified as non-small cell lung cancer not otherwise specified (NSCLC-NOS) with an explanation included in the pathology report.
Lung Cancer Reporting (Resection Specimens)
High Priority: YES
Measure Type: Process
Submission Methods: Claims, Registry
Description: Pathology reports based on lung resection specimens with a diagnosis of primary lung carcinoma that include the pT category, pN category and for non-small cell lung cancer (NSCLC), histologic type.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Adenocarcinoma of left lung
- Malignant neoplasm of upper lobe bronchus
- Malignant neoplasm of upper lobe of left lung
- Neoplasm of bronchus of left upper lobe
- Primary adenocarcinoma of upper lobe of left lung
- Primary large cell carcinoma of lung
- Primary large cell carcinoma of upper lobe of left lung
- Primary malignant neoplasm of bronchus of left upper lobe
- Primary malignant neoplasm of upper lobe of left lung
- Primary non-small cell carcinoma of left lung
- Primary non-small cell carcinoma of upper lobe of left lung
- Primary small cell carcinoma of left lung
- Primary small cell carcinoma of upper lobe of left lung
- Primary squamous cell carcinoma of bronchus
- Primary squamous cell carcinoma of bronchus in left upper lobe
- Primary squamous cell carcinoma of left lung
- Primary squamous cell carcinoma of upper lobe of left lung
- Squamous cell carcinoma of bronchus in left upper lobe
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Table of NeoplasmsClinical
Anatomical sites in the Table of Neoplasms that reference this code family.
| Site | Malig. Primary | Malig. Secondary | Ca in situ | Benign | Uncertain | Unspec. |
|---|---|---|---|---|---|---|
| bronchus › upper lobe of lung | C34.1 | C78.0 | D02.2 | D14.3 | D38.1 | D49.1 |
| lingula, lung | C34.1 | C78.0 | D02.2 | D14.3 | D38.1 | D49.1 |
| lung › azygos lobe | C34.1 | C78.0 | D02.2 | D14.3 | D38.1 | D49.1 |
| lung › lingula | C34.1 | C78.0 | D02.2 | D14.3 | D38.1 | D49.1 |
| lung › upper lobe | C34.1 | C78.0 | D02.2 | D14.3 | D38.1 | D49.1 |
Patient EducationClinical
Lung Cancer
Lung cancer is cancer that forms in tissues of the lung, usually in the cells that line the air passages. It is the leading cause of cancer death in both men and women.
The full article covers:
- What is lung cancer?
- Who is more likely to develop lung cancer?
- What are the symptoms of lung cancer?
- How is lung cancer diagnosed?
- What are the treatments for lung cancer?
- Can lung cancer be prevented?
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert C34.12 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About C34.12Overview
Is C34.12 (Malignant neoplasm of upper lobe, bronchus or lung) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report malignant neoplasm of upper lobe, left bronchus or lung on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does C34.12 group to?
When malignant neoplasm of upper lobe, left bronchus or lung is the principal diagnosis on an inpatient stay, it groups to MS-DRG 180, 181, 182, with relative weights from 0.7440 to 1.7660 depending on complications. Higher weights mean higher Medicare reimbursement.
What is the ICD-9 equivalent of C34.12?
Under the General Equivalence Mappings, malignant neoplasm of upper lobe, left bronchus or lung converts to ICD-9-CM 162.3 (mal neo upper lobe lung). The mapping is approximate, so confirm the match fits the documentation.
Footnotes
[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:
- The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
- The condition places limitations on self-care, independent living, and social interactions.
