ICD-10-CM 2027 diagnosis code

C00Malignant neoplasm of lip

Not billable — use a more specific code

C00 is a header code, so it can't be reported by itself. Choose one of the 9 more specific codes beneath it.

Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About C00

C00 is the ICD-10-CM diagnosis code for malignant neoplasm of lip. It belongs to block C00-C14 (malignant neoplasms of lip, oral cavity and pharynx) and chapter 2 (neoplasms). It is a header code, so it can't be reported by itself; one of its 9 subcodes must be used instead.

To report this condition, pick the subcode that matches the documentation: C00.0 (lip), C00.1 (lip), C00.2 (unspecified), C00.3 (aspect), C00.4 (aspect), C00.5 (unspecified, inner aspect), C00.6 (unspecified), C00.8 (lip) and 1 more.

Don't report C00 together with the conditions in its Excludes1 note: malignant melanoma of lip (C43.0), Merkel cell carcinoma of lip (C4A.0) and other and unspecified malignant neoplasm of skin of lip (C44.0-).

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

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Specific codes under C00

Coding notes

Excludes1Not coded here — never report together with this code

malignant melanoma of lip (C43.0)
Merkel cell carcinoma of lip (C4A.0)
other and unspecified malignant neoplasm of skin of lip (C44.0-)

Use additional codeAdd a secondary code to fully describe the condition

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

Notes that apply from higher levels

Instructions written at a parent level also apply to C00.

Broader instructions also apply from Chapter 2: Neoplasms.

Codes whose notes reference C00

C44.0Excludes1
D59.39Code also
D63.0Code first
D84.81Code first
E08Code first
G13.0Code first
G13.1Code first
G32.8Code first
G32.81Code first
G53Code first
G55Code first
G63Code first
G73.1Code first
G73.3Code first
G91.4Code first
G99.2Code first
I31.31Code first
J91.0Code first
M36.0Code first
Z15.0Code first

Code history

2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027

FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
No changes since FY2016.

Common questions about C00

Is C00 billable?: No. C00 is a header code. Report one of its more specific subcodes instead.