C79
Secondary malignant neoplasm of other and unspecified sites
Not billable — category only FY2026 2025-10-01 → 2026-09-30
Exclusions 2 never code together
Instructional notes 8
C00-D49chapter
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).C25.9
Index entries leading here filed at null
No alphabetic index entry points at this code.
Subordinate codes 10
C79.0 Secondary malignant neoplasm of kidney and renal pelvis C79.1 Sec malig neoplm of bladder and oth and unsp urinary organs C79.2 Secondary malignant neoplasm of skin C79.3 Secondary malignant neoplasm of brain and cerebral meninges C79.4 Secondary malig neoplasm of and unsp parts of nervous sys C79.5 Secondary malignant neoplasm of bone and bone marrow C79.6 Secondary malignant neoplasm of ovary C79.7 Secondary malignant neoplasm of adrenal gland C79.8 Secondary malignant neoplasm of other specified sites C79.9 Secondary malignant neoplasm of unspecified site
Additional references
AHA Coding Clinic® Licence required
Official coding advice for this code. Published by the American Hospital Association. Not included in this installation.