2019 ICD-10-CM Diagnosis Code C79.9

Secondary malignant neoplasm of unspecified site

    2016 2017 2018 2019 Billable/Specific Code
  • C79.9 is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes.
  • The 2019 edition of ICD-10-CM C79.9 became effective on October 1, 2018.
  • This is the American ICD-10-CM version of C79.9 - other international versions of ICD-10 C79.9 may differ.
Applicable To
  • Metastatic cancer NOS
  • Metastatic disease NOS
Type 1 Excludes
Type 1 Excludes Help
A type 1 excludes note is a pure excludes. It means "not coded here". A type 1 excludes note indicates that the code excluded should never be used at the same time as C79.9. A type 1 excludes note is for used for when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
  • carcinomatosis NOS (
    ICD-10-CM Diagnosis Code C80.0

    Disseminated malignant neoplasm, unspecified

      2016 2017 2018 2019 Billable/Specific Code
    Applicable To
    • Carcinomatosis NOS
    • Generalized cancer, unspecified site (primary) (secondary)
    • Generalized malignancy, unspecified site (primary) (secondary)
    C80.0
    )
  • generalized cancer NOS (
    ICD-10-CM Diagnosis Code C80.0

    Disseminated malignant neoplasm, unspecified

      2016 2017 2018 2019 Billable/Specific Code
    Applicable To
    • Carcinomatosis NOS
    • Generalized cancer, unspecified site (primary) (secondary)
    • Generalized malignancy, unspecified site (primary) (secondary)
    C80.0
    )
  • malignant (primary) neoplasm of unspecified site (
    ICD-10-CM Diagnosis Code C80.1

    Malignant (primary) neoplasm, unspecified

      2016 2017 2018 2019 Billable/Specific Code
    Applicable To
    • Cancer NOS
    • Cancer unspecified site (primary)
    • Carcinoma unspecified site (primary)
    • Malignancy unspecified site (primary)
    Type 1 Excludes
    • secondary malignant neoplasm of unspecified site (C79.9)
    C80.1
    )
The following code(s) above C79.9 contain annotation back-references
Annotation Back-References
In this context, annotation back-references refer to codes that contain:
  • Applicable To annotations, or
  • Code Also annotations, or
  • Code First annotations, or
  • Excludes1 annotations, or
  • Excludes2 annotations, or
  • Includes annotations, or
  • Note annotations, or
  • Use Additional annotations
that may be applicable to C79.9:
  • C00-D49
    2019 ICD-10-CM Range C00-D49

    Neoplasms

    Note
    • Functional activity
    • All neoplasms are classified in this chapter, whether they are functionally active or not. An additional code from Chapter 4 may be used, to identify functional activity associated with any neoplasm.
    • Morphology [Histology]
    • Chapter 2 classifies neoplasms primarily by site (topography), with broad groupings for behavior, malignant, in situ, benign, etc. The Table of Neoplasms should be used to identify the correct topography code. In a few cases, such as for malignant melanoma and certain neuroendocrine tumors, the morphology (histologic type) is included in the category and codes.
    • Primary malignant neoplasms overlapping site boundaries
    • A primary malignant neoplasm that overlaps two or more contiguous (next to each other) sites should be classified to the subcategory/code .8 ('overlapping lesion'), unless the combination is specifically indexed elsewhere. For multiple neoplasms of the same site that are not contiguous, such as tumors in different quadrants of the same breast, codes for each site should be assigned.
    • Malignant neoplasm of ectopic tissue
    • Malignant neoplasms of ectopic tissue are to be coded to the site mentioned, e.g., ectopic pancreatic malignant neoplasms are coded to pancreas, unspecified (C25.9).
    Neoplasms
  • C79
    ICD-10-CM Diagnosis Code C79

    Secondary malignant neoplasm of other and unspecified sites

      2016 2017 2018 2019 Non-Billable/Non-Specific Code
    Type 1 Excludes
    • secondary carcinoid tumors (C7B.-)
    • secondary neuroendocrine tumors (C7B.-)
    Secondary malignant neoplasm of other and unspecified sites
Approximate Synonyms
  • Adenocarcinoma metastatic to unspecified site
  • Cancer metastatic to unspecified site
  • Cancer of the prostate with metastasis
  • Colon cancer metastatic to unspecified site
  • Esophageal cancer metastatic to unspecified site
  • Female breast cancer metastatic to unspecified site
  • Lung cancer metastatic to unspecified site
  • Male breast cancer metastatic to unspecified site
  • Melanoma, metastatic
  • Metastasis from malignant tumor of colon
  • Metastasis from malignant tumor of esophagus
  • Metastasis from malignant tumor of lung
  • Metastasis from malignant tumor of prostate
  • Metastatic malignant melanoma
  • Metastatic squamous cell carcinoma
  • Metastatic undifferentiated large cell carcinoma
  • Secondary adenocarcinoma
  • Secondary malignant neoplasm of unknown site
  • Secondary small cell carcinoma of unspecified site
  • Small cell carcinoma metastatic to unspecified site
  • Squamous cell carcinoma metastatic to unspecified site
  • Squamous cell carcinoma of skin metastatic to unspecif
  • Squamous cell carcinoma of skin metastatic to unspecified site
  • Thyroid cancer metastatic to unspecified site
  • Undifferentiated large cell cancer metastatic to unspe
Clinical Information
  • A tumor that has spread from its original (primary) site of growth to another site, close to or distant from the primary site. Metastasis is characteristic of advanced malignancies, but in rare instances can be seen in neoplasms lacking malignant morphology.
ICD-10-CM C79.9 is grouped within Diagnostic Related Group(s) (MS-DRG v36.0):
  • 826 Myeloproliferative disorders or poorly differentiated neoplasms with major o.r. Procedure with mcc
  • 827 Myeloproliferative disorders or poorly differentiated neoplasms with major o.r. Procedure with cc
  • 828 Myeloproliferative disorders or poorly differentiated neoplasms with major o.r. Procedure without cc/mcc
  • 829 Myeloproliferative disorders or poorly differentiated neoplasms with other procedure with cc/mcc
  • 830 Myeloproliferative disorders or poorly differentiated neoplasms with other procedure without cc/mcc
  • 843 Other myeloproliferative disorders or poorly differentiated neoplastic diagnoses with mcc
  • 844 Other myeloproliferative disorders or poorly differentiated neoplastic diagnoses with cc
  • 845 Other myeloproliferative disorders or poorly differentiated neoplastic diagnoses without cc/mcc

Convert C79.9 to ICD-9-CM

Code History
  • 2016 (effective 10/1/2015): New code (first year of non-draft ICD-10-CM)
  • 2017 (effective 10/1/2016): No change
  • 2018 (effective 10/1/2017): No change
  • 2019 (effective 10/1/2018): No change
Code annotations containing back-references to C79.9:
  • Type 1 Excludes: C80.1
    ICD-10-CM Diagnosis Code C80.1

    Malignant (primary) neoplasm, unspecified

      2016 2017 2018 2019 Billable/Specific Code
    Applicable To
    • Cancer NOS
    • Cancer unspecified site (primary)
    • Carcinoma unspecified site (primary)
    • Malignancy unspecified site (primary)
    Type 1 Excludes
    • secondary malignant neoplasm of unspecified site (C79.9)

Diagnosis Index entries containing back-references to C79.9:

ICD-10-CM Codes Adjacent To C79.9
C79.61 Secondary malignant neoplasm of right ovary
C79.62 Secondary malignant neoplasm of left ovary
C79.7 Secondary malignant neoplasm of adrenal gland
C79.70 Secondary malignant neoplasm of unspecified adrenal gland
C79.71 Secondary malignant neoplasm of right adrenal gland
C79.72 Secondary malignant neoplasm of left adrenal gland
C79.8 Secondary malignant neoplasm of other specified sites
C79.81 Secondary malignant neoplasm of breast
C79.82 Secondary malignant neoplasm of genital organs
C79.89 Secondary malignant neoplasm of other specified sites
C79.9 Secondary malignant neoplasm of unspecified site
C80 Malignant neoplasm without specification of site
C80.0 Disseminated malignant neoplasm, unspecified
C80.1 Malignant (primary) neoplasm, unspecified
C80.2 Malignant neoplasm associated with transplanted organ
C81 Hodgkin lymphoma
C81.0 Nodular lymphocyte predominant Hodgkin lymphoma
C81.00 …… unspecified site
C81.01 …… lymph nodes of head, face, and neck
C81.02 …… intrathoracic lymph nodes
C81.03 …… intra-abdominal lymph nodes

Reimbursement claims with a date of service on or after October 1, 2015 require the use of ICD-10-CM codes.