Neoplasms (C00–D49) ICD-10-CM
Chapter 2 of the ICD-10-CM classification spans codes C00–D49 and contains 2,148 diagnosis codes for neoplasms, of which 1,706 are billable. The chapter is organized into 21 sections listed below, each linking to its code ranges and individual codes.
Chapter Coding Notes
Note: 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).
Sections in This Chapter 21 ranges · 2,148 codes
The info icon previews the code ranges inside each row and its instructional notations from the official Tabular List.
About Chapter 2
Tumors in this chapter include cancers and tumors labeled in situ, benign, uncertain behavior, or unspecified behavior.
The cancer groups mostly separate tumors by body site, including the mouth and throat, digestive organs, lungs and other chest organs, skin, breast, urinary tract, and brain. Other groups distinguish malignant, secondary, and benign neuroendocrine tumors. The remaining groups separate in situ tumors, benign tumors, tumors of uncertain behavior, and tumors of unspecified behavior.
FY 2027 changes: The FY 2027 ICD-10-CM update, effective October 1, 2026, added 3 codes in this chapter.
Questions About This Page
How many codes are in the C00-D49 range?
The C00-D49 range contains 2,148 ICD-10-CM diagnosis codes in FY 2027. 1,706 of them are billable, and the rest are category headers that organize the chapter.
What conditions does C00-D49 cover?
The range covers neoplasms. The sections listed above break it into groups of related conditions, and each one links to its own page with the full code list.
Related References
Source: CMS FY 2027 ICD-10-CM Tabular List and order file, effective October 1, 2026 through September 30, 2027.
