C43.9
Malignant melanoma of skin, unspecified
Billable FY2026 2025-10-01 → 2026-09-30
This is the unspecified option. 9 more
specific codes sit alongside it. Worth
checking whether the documentation supports one of them.
Exclusions 4 never code together
C43code
Excludes1 — never code together. The excluded condition and this one are mutually exclusive.
Excludes2 — not included here, but the patient may have both. Code both when documented.
Instructional notes 10
C43.9code
Inclusion terms
- Malignant melanoma of unspecified site of skin
- Melanoma (malignant) NOS
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
Alongside this code 9 same parent — C43
C43.0 Malignant melanoma of lip C43.1 Malignant melanoma of eyelid, including canthus category C43.2 Malignant melanoma of ear and external auricular canal category C43.3 Malignant melanoma of other and unspecified parts of face category C43.4 Malignant melanoma of scalp and neck C43.5 Malignant melanoma of trunk category C43.6 Malignant melanoma of upper limb, including shoulder category C43.7 Malignant melanoma of lower limb, including hip category C43.8 Malignant melanoma of overlapping sites of skin
Medications 1
MED-RT files conditions by MeSH, which carves the world differently from ICD-10. These are name matches on this code's description, offered as candidates — not as an assertion that they are this code.
Additional references
AHA Coding Clinic® Licence required
Official coding advice for this code. Published by the American Hospital Association. Not included in this installation.