2026 ICD-10-CM Diagnosis Code C39.9Malignant neoplasm of lower respiratory tract, part unspecified
ICD-10-CM Codes›C00–D49›C30-C39›C39
- Billable — Valid for Submission
- Chronic Condition
C39.9 is a billable ICD-10-CM diagnosis code for malignant neoplasm of lower respiratory tract, part unspecified. 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. Coders also document this condition as malignant neoplasm of lower respiratory tract. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Respiratory cancers.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Malignant neoplasm of lower respiratory tract
- Malignant neoplasm of respiratory system
- Primary malignant neoplasm of respiratory tract
- Primary rhabdomyosarcoma of respiratory organ
- Primary squamous cell carcinoma of respiratory system
- Primary synovial sarcoma
- Primary synovial sarcoma of respiratory organ
- Synovial sarcoma
Tabular List NotesGuidance
Coding notes and annotation back-references applicable to this code.
Inclusion Terms
- Malignant neoplasm of respiratory tract NOS
These terms are the conditions for which that code is to be used. The terms may be synonyms of the code title, or, in the case of "other specified" codes, the terms are a list of the various conditions assigned to that code. The inclusion terms are not necessarily exhaustive. Additional terms found only in the Alphabetic Index may also be assigned to a code.
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.
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 C39.9 to ICD-9-CMHistory
Code HistoryHistory
Questions About C39.9Overview
Is C39.9 a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report malignant neoplasm of lower respiratory tract, part unspecified on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does C39.9 group to?
When malignant neoplasm of lower respiratory tract, part unspecified 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 C39.9?
Under the General Equivalence Mappings, malignant neoplasm of lower respiratory tract, part unspecified converts to ICD-9-CM 165.8 (mal neo thorax/resp NEC) and 165.9 (mal neo resp system NOS). 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.
