Alphabetic Index FY2027

D49

Neoplasms of unspecified behavior

FY2027Chapter 2: Neoplasms/D49 Neoplasms of unspecified behavior

Non-billable headerNot valid on its own. Use one of the more specific codes under it.

D49 is a non-billable ICD-10-CM code category for neoplasms of unspecified behavior. 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 D49.0 Neoplasm of unspecified behavior of digestive system; D49.1 Neoplasm of unspecified behavior of respiratory system; D49.2 Neoplasm of unspecified behavior of bone, soft tissue, and skin; D49.3 Neoplasm of unspecified behavior of breast and 6 more. Its coding notes include 1 Excludes2 entry.

Excludes2

Not included here. Both codes may be reported if the patient has both conditions.

This code
  • neoplasms of uncertain behavior (D37-D44, D48)

Includes

Further defines or gives examples of the content of the category.

This code
  • 'growth' NOS
  • neoplasm NOS
  • new growth NOS
  • tumor NOS

Notes

This code
  • Category D49 classifies by site neoplasms of unspecified morphology and behavior. The term 'mass', unless otherwise stated, is not to be regarded as a neoplastic growth.
Also from chapter/block level (8 notes)
Inherited from Chapter 2 Neoplasms
  • 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).

More specific codes under D49 10