2026 ICD-10-CM Diagnosis Code C34.32Malignant neoplasm of lower lobe, left bronchus or lung

ICD-10-CM Codes›C00–D49›C30-C39›C34

ICD-10-CM C34.32
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

C34.32 is a billable ICD-10-CM diagnosis code for malignant neoplasm of lower 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

ICD-10-CM Code
C34.32
Billable Status
Yes — Valid for Submission
Code Describes
Malignant neoplasm of lower lobe, left bronchus or lung
Short Description
Malignant neoplasm of lower lobe, left bronchus or lung
Same as the full description in the CMS dataset.
Parent Code
C34.3
Malignant neoplasm of lower lobe, bronchus or lung

Code Classification

ChapterC00–D49Neoplasms
SectionC30-C39Malignant neoplasms of respiratory and intrathoracic organs
CategoryC34Malignant neoplasm of bronchus and lung
This CodeC34.32Malignant neoplasm of lower lobe, left bronchus or lung

Quality Payment Program MeasuresBilling

Medicare quality measures that can apply when C34.32 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.

View Measure

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.

View Measure

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Adenocarcinoma of left lung
  • Carcinoma of lower lobe of lung
  • Malignant neoplasm of lower lobe bronchus
  • Malignant neoplasm of lower lobe of left lung
  • Neoplasm of bronchus of left lower lobe
  • Primary adenocarcinoma of lower lobe of left lung
  • Primary large cell carcinoma of lower lobe of left lung
  • Primary large cell carcinoma of lung
  • Primary malignant neoplasm of bronchus of left lower lobe
  • Primary malignant neoplasm of lower lobe of left lung
  • Primary non-small cell carcinoma of left lung
  • Primary non-small cell carcinoma of lower lobe of left lung
  • Primary small cell carcinoma of left lung
  • Primary small cell carcinoma of lower lobe of left lung
  • Primary squamous cell carcinoma of bronchus
  • Primary squamous cell carcinoma of bronchus in left lower lobe
  • Primary squamous cell carcinoma of left lung
  • Primary squamous cell carcinoma of lower lobe of left lung
  • Squamous cell carcinoma of bronchus in left lower lobe

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR NEO022
Respiratory cancers
Default principal diagnosis: inpatient Yes · outpatient Yes

Table of NeoplasmsClinical

Anatomical sites in the Table of Neoplasms that reference this code family.

SiteMalig.
Primary		Malig.
Secondary		Ca
in situ		BenignUncertainUnspec.
bronchus › lower lobe of lungC34.3C78.0D02.2D14.3D38.1D49.1
lung › lower lobeC34.3C78.0D02.2D14.3D38.1D49.1

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 C34.32 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
162.5 Mal neo lower lobe lung
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About C34.32Overview

Is C34.32 (Malignant neoplasm of lower lobe, bronchus or lung) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report malignant neoplasm of lower lobe, left bronchus or lung on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does C34.32 group to?

When malignant neoplasm of lower 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 C34.32?

Under the General Equivalence Mappings, malignant neoplasm of lower lobe, left bronchus or lung converts to ICD-9-CM 162.5 (mal neo lower 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.