Malignant neoplasm of other and ill-defined sites in the respiratory system and intrathoracic organs (C39) ICD-10-CM
The C39 code range covers malignant neoplasm of other and ill-defined sites in the respiratory system and intrathoracic organs with 3 ICD-10-CM diagnosis codes. 2 of them are billable and valid for claim submission in fiscal year 2026, and the category headers group them but cannot themselves be billed.
Use Additional Code
The “use additional code” indicates that a secondary code could be used to further specify the patient’s condition. This note is not mandatory and is only used if enough information is available to assign an additional code.
- code to identify:
- exposure to environmental tobacco smoke Z77.22
- exposure to tobacco smoke in the perinatal period P96.81
- history of tobacco dependence Z87.891
- occupational exposure to environmental tobacco smoke Z57.31
- tobacco dependence F17
- tobacco use Z72.0
Type 1 Excludes
A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
Codes in the C39 Range 3 codes · 2 billable
About the C39 Code Range
The ICD-10 code C39 covers malignant tumors located in various unspecified or less clearly defined parts of the respiratory system and organs inside the chest. It is used when the cancer's exact site in the respiratory or thoracic area cannot be precisely classified.
More specifically, codes like C39.0 and C39.9 represent cancers in the upper and lower regions of the respiratory tract, respectively. The ICD-10 code for malignant neoplasm of upper respiratory tract (C39.0) helps identify cancers in less specific parts of the upper airways, which may go by names such as "Primary malignant neoplasm of upper respiratory tract." Similarly, C39.9 is assigned to malignant tumors in the lower respiratory tract and includes a range of types like primary synovial sarcoma, rhabdomyosarcoma, or squamous cell carcinoma of the respiratory system. These classifications assist medical coders and health professionals in capturing complex cancer cases involving unclear or generalized thoracic locations, ensuring accurate documentation and reporting for treatment and research purposes.
Questions About This Page
How many billable codes are in the C39 range?
Of the 3 codes in this range, 2 are billable and valid for claim submission from October 1, 2025 through September 30, 2026. Category header codes group them but cannot be reported on claims.
What does the C39 range classify?
The range classifies malignant neoplasm of other and ill-defined sites in the respiratory system and intrathoracic organs. Each code links to its own reference page with billing status, MS-DRG grouping, coding notes, and clinical information.
Related References
Source: CMS FY 2026 ICD-10-CM Tabular List and order file, effective October 1, 2025 through September 30, 2026.
