Coding and coverage · ICD-10-CM

C40

C40.3 Malignant neoplasm of short bones of lower limb

Not billable (header)Chapter 2

Report one of the more specific codes below.

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Codes under this one

  • C40.30 Malignant neoplasm of short bones of unspecified lower limb
  • C40.31 Malignant neoplasm of short bones of right lower limb
  • C40.32 Malignant neoplasm of short bones of left lower limb

Instructional notes

Chapter 2

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).

C40

Use additional codeAdd a second code for the full picture.
  • code to identify major osseous defect, if applicable (M89.7-)

Chapter 2: Neoplasms · C00-C96 Malignant neoplasms (C00-C96)

Source: ICD-10-CM FY 2027 code descriptions and tabular list (CMS and CDC National Center for Health Statistics), effective 2026-10-01 through 2027-09-30 · CMS ICD-10 files. HCC mapping: CMS-HCC V28, payment year 2027. As of 2026-11-04.

Coverage and payment depend on the claim details; confirm with the Medicare Administrative Contractor.