2026 ICD-10-CM Diagnosis Code C78Secondary malignant neoplasm of respiratory and digestive organs

ICD-10-CM Codes›C00–D49›C76-C80›C78

ICD-10-CM C78
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

C78 is a non-billable ICD-10-CM category code for secondary malignant neoplasm of respiratory and digestive organs, so it cannot be submitted on claims. Use a more specific code from this category instead, such as C78.00, C78.01, C78.02, and C78.1.

Code Identity

ICD-10-CM Code
C78
Billable Status
No — Non-Billable Category
Code Describes
Secondary malignant neoplasm of respiratory and digestive organs
Short Description
Secondary malignant neoplasm of resp and digestive organs
Chapter
C76-C80
Malignant neoplasms of ill-defined, other secondary and unspecified sites

Code Classification

ChapterC00–D49Neoplasms
SectionC76-C80Malignant neoplasms of ill-defined, other secondary and unspecified sites
CategoryC78Secondary malignant neoplasm of respiratory and digestive organs
This CodeC78Secondary malignant neoplasm of respiratory and digestive organs

Specific Coding for Secondary malignant neoplasm of resp and digestive organsOverview

Non-specific codes like C78 require more characters. Use one of these billable codes instead:

  • C78.0 for Secondary malignant neoplasm of lung

  • Use C78.00 for Secondary malignant neoplasm of unspecified lung

  • Use C78.01 for Secondary malignant neoplasm of right lung

  • Use C78.02 for Secondary malignant neoplasm of left lung

  • Use C78.1 for Secondary malignant neoplasm of mediastinum

  • Use C78.2 for Secondary malignant neoplasm of pleura

  • C78.3 for Secondary malignant neoplasm of other and unspecified respiratory organs

  • Use C78.30 for Secondary malignant neoplasm of unspecified respiratory organ

  • Use C78.39 for Secondary malignant neoplasm of other respiratory organs

  • Use C78.4 for Secondary malignant neoplasm of small intestine

  • Use C78.5 for Secondary malignant neoplasm of large intestine and rectum

  • Use C78.6 for Secondary malignant neoplasm of retroperitoneum and peritoneum

  • Use C78.7 for Secondary malignant neoplasm of liver and intrahepatic bile duct

  • C78.8 for Secondary malignant neoplasm of other and unspecified digestive organs

  • Use C78.80 for Secondary malignant neoplasm of unspecified digestive organ

  • Use C78.89 for Secondary malignant neoplasm of other digestive organs

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Type 1 Excludes

  • secondary carcinoid tumors of liver C7B.02
  • secondary carcinoid tumors of peritoneum C7B.04

Type 2 Excludes

  • lymph node metastases C77.0

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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 C78Overview

Is C78 a billable code?

No. This is a category header that groups the codes for secondary malignant neoplasm of respiratory and digestive organs, and headers cannot be submitted on claims. Claims for secondary malignant neoplasm of respiratory and digestive organs need a more specific code from this category, such as C78.00, C78.01, and C78.02.