ICD10

ICD-10 Code C39: Malignant neoplasm of other and ill-defined sites in the respiratory system and intrathoracic organs

C39 is an ICD-10 diagnosis entry used to group records related to Malignant neoplasm of other and ill-defined sites in the respiratory system and intrathoracic organs. You may see this entry in coding references, medical records, or claims workflows when a broader diagnosis category is being reviewed before a more specific code is chosen. ICD-10 entries help standardize how diagnoses are organized for coding, reporting, analytics, and documentation. This code sits within the broader ICD-10 area for Neoplasms (C00-D49).

Reviewed by HealthAssure Clinical TeamUpdated 21 May 2026

What is this code?

ICD-10 entries help standardize how diagnoses are organized for coding, reporting, analytics, and documentation. This code sits within the broader ICD-10 area for Neoplasms (C00-D49).

When is it used?

  • May be used when a clinician documents malignant neoplasm of other and ill-defined sites in the respiratory system and intrathoracic organs in a patient's medical record.
  • May appear in hospital records, claims, referrals, and clinical documentation.
  • This code may act more like a grouping or parent code, so a more specific child code may be used in final documentation when available.

What it does not mean

  • A code alone does not explain severity, treatment plan, or outcome.
  • A medical code should not be treated as a substitute for a doctor's diagnosis or advice.
  • This entry may represent a broader category rather than the most specific billable code.

Code hierarchy

chapter
2Neoplasms (C00-D49)
block
C00-C96Malignant neoplasms
block
C00-C75Malignant neoplasms, stated or presumed to be primary (of specified sites), and certain specified histologies, except neuroendocrine, and of lymphoid, hematopoietic and related tissue
block
C30-C39Malignant neoplasms of respiratory and intrathoracic organs
currentC30-C39

Official coding notes

Applicable to
  • 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)
Excludes1 (do not code together)
  • intrathoracic malignant neoplasm NOS (C76.1)
  • thoracic malignant neoplasm NOS (C76.1)
Use 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)

Where you may see this code

You may see this entry in coding references, medical records, or claims workflows when a broader diagnosis category is being reviewed before a more specific code is chosen.

Related specialists

OncologistGeneral PhysicianPulmonologist

Coding guidelines

Compatibility

Legacy code aligns to an official FY 2026 category. Frontend should resolve to the official category page and surface the billable child codes.
Legacy codes
C39
Replacement codes
C39.0 — Malignant neoplasm of upper respiratory tract, part unspecifiedC39.9 — Malignant neoplasm of lower respiratory tract, part unspecified

Common synonyms

Malignant neoplasm of other and ill-defined sites in the respiratory system and intrathoracic organs

Frequently asked questions

Code details

CodeC39
SystemICD10
Display nameMalignant neoplasm of other and ill-defined sites in the respiratory system and intrathoracic organs
ChapterNeoplasms (C00-D49)
BlockMalignant neoplasms of respiratory and intrathoracic organs

Flags

BillableNo
Valid clinical useNo

Source

SourceICD-10
Version2026-annual
Releaseannual
Year2026

About this content

This page is prepared by HealthAssure's clinical team using official coding standards from ICD-10. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.