C02.9

Malignant neoplasm of tongue, unspecified

FY2027Chapter 2: Neoplasms/C00–C14 Malignant neoplasms of lip, oral cavity and pharynx

BillableComplete code, valid to report

Use additional code

Care settingsHome Health Primary · MMTA - Infectious Disease, Neoplasms, and Blood-Forming Diseases

C02.9 (also written C029) is a billable ICD-10-CM diagnosis code for malignant neoplasm of tongue, unspecified. It is part of the FY2027 code set, effective October 1, 2026. It is one of the 7 codes in category C02 (Malignant neoplasm of other and unspecified parts of tongue). Its coding notes include a Use additional code instruction.

Guidelines tip

From the FY2027 Official Guidelines. ICD10Ref adds no rules of its own.

A primary malignancy code stays in use until treatment directed at that site is completed. After that, with no evidence of disease at the site, Z85 gives the former site.

Guidelines I.C.2.mCurrent malignancy versus personal history of malignancyRead the official text

Use additional code

Add the listed code as a secondary code, if known.

Inherited from C02 Malignant neoplasm of other and unspecified parts of tongue

code to identify:
- alcohol abuse and dependence (F10.-)
- history of tobacco dependence (Z87.891)
- tobacco dependence (F17.-)
- tobacco use (Z72.0)

Care settings

How CMS programs treat this code. These are CMS claim edits and list entries, not coverage or eligibility rules.

Home Health Primary

Accepted as the primary (principal) diagnosis on a home health claim. The Home Health Grouper assigns it to the MMTA - Infectious Disease, Neoplasms, and Blood-Forming Diseases clinical group.

Source: CMS Home Health Grouper Software v07.2.26, effective October 1, 2026

Notes

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).