2026 ICD-10-CM Diagnosis Code D00.02Carcinoma in situ of buccal mucosa

ICD-10-CM CodesC00–D49D00-D09D00

ICD-10-CM D00.02
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

D00.02 is a billable ICD-10-CM diagnosis code for carcinoma in situ of buccal mucosa. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 146 through 148. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Head and neck cancers - lip and oral cavity.

Code Identity

ICD-10-CM Code
D00.02
Billable Status
Yes — Valid for Submission
Code Describes
Carcinoma in situ of buccal mucosa
Short Description
Carcinoma in situ of buccal mucosa
Same as the full description in the CMS dataset.
Parent Code
Carcinoma in situ of lip, oral cavity and pharynx

Code Classification

ChapterC00–D49Neoplasms
SectionD00-D09In situ neoplasms
CategoryD00Carcinoma in situ of oral cavity, esophagus and stomach
This CodeD00.02Carcinoma in situ of buccal mucosa

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Carcinoma in situ of buccal mucosa
  • Carcinoma in situ of lower buccal sulcus
  • Carcinoma in situ of lower labial sulcus
  • Carcinoma in situ of oral cavity
  • Carcinoma in situ of upper buccal sulcus
  • Carcinoma in situ of vestibule of mouth
  • Carcinoma in situ upper labial sulcus
  • Carcinoma-in-situ of oral mucosa
  • Neoplasm of buccal mucosa
  • Neoplasm of mandibular buccal sulcus
  • Neoplasm of mandibular labial sulcus
  • Neoplasm of maxillary buccal sulcus
  • Neoplasm of maxillary labial sulcus

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR NEO002
Head and neck cancers - lip and oral cavity
Default principal diagnosis: inpatient Yes · outpatient Yes

Table of NeoplasmsClinical

Anatomical sites in the Table of Neoplasms that reference this code family.

SiteMalig.
Primary
Malig.
Secondary
Ca
in situ
BenignUncertainUnspec.
alveolar sulcusC06.1C79.89D00.02D10.39D37.09D49.0
buccal (cavity) commissureC06.0C79.89D00.02D10.39D37.09D49.0
buccal (cavity) groove (lower) (upper)C06.1C79.89D00.02D10.39D37.09D49.0
buccal (cavity) mucosaC06.0C79.89D00.02D10.39D37.09D49.0
buccal (cavity) sulcus (lower) (upper)C06.1C79.89D00.02D10.39D37.09D49.0
cheek inner aspectC06.0C79.89D00.02D10.39D37.09D49.0
cheek internalC06.0C79.89D00.02D10.39D37.09D49.0
cheek mucosaC06.0C79.89D00.02D10.39D37.09D49.0
labial [See Also: Neoplasm, lip] sulcus (lower) (upper)C06.1C79.89D00.02D10.39D37.09D49.0
mucosa buccalC06.0C79.89D00.02D10.39D37.09D49.0
mucosa cheekC06.0C79.89D00.02D10.39D37.09D49.0
mucosa oralC06.0C79.89D00.02D10.39D37.09D49.0
oral (cavity) mucosaC06.0C79.89D00.02D10.39D37.09D49.0

Patient EducationClinical

Oral Cancer

Oral cancer is cancer of the mouth. It is a type of head and neck cancer. Most oral cancers are squamous cell cancers. They begin in the flat cells that cover the surfaces of your mouth, tongue, and lips. The cancer cells may spread into deeper tissue as the cancer grows.

The full article covers:

  • What is oral cancer?
  • Who is more likely to develop oral cancer?
  • What are the symptoms of oral cancer?
  • How is oral cancer diagnosed?
  • What are the treatments for oral cancer?
  • Can oral cancer be prevented?

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert D00.02 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
230.0 Ca in situ oral cav/phar
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About D00.02Overview

Is D00.02 (Carcinoma in situ of lip, oral cavity and pharynx) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report carcinoma in situ of buccal mucosa on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does D00.02 group to?

When carcinoma in situ of buccal mucosa is the principal diagnosis on an inpatient stay, it groups to MS-DRG 146, 147, 148, with relative weights from 0.7971 to 2.1174 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of D00.02?

Under the General Equivalence Mappings, carcinoma in situ of buccal mucosa converts to ICD-9-CM 230.0 (ca in situ oral cav/phar). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.