C80
Malignant neoplasm without specification of site
C80 is a non-billable ICD-10-CM code category for malignant neoplasm without specification of site. Report a more specific code from it instead. It is part of the FY2027 code set, effective October 1, 2026. The more specific codes under it are C80.0 Disseminated malignant neoplasm, unspecified; C80.1 Malignant (primary) neoplasm, unspecified and C80.2 Malignant neoplasm associated with transplanted organ. Its coding notes include 2 Excludes1 entries.
Guidelines tip
From the FY2027 Official Guidelines. ICD10Ref adds no rules of its own.
C80.0 is not a substitute for coding the primary site and every known secondary site. C80.1 is used only when the primary site cannot be determined.
Excludes1
Not coded here. The listed conditions generally should not be reported together.
- malignant carcinoid tumor of unspecified site (C7A.00)
- malignant neoplasm of specified multiple sites- code to each site
Notes
Also from chapter/block level (8 notes)
- 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).