2026 ICD-10-CM Diagnosis Code D01.2Carcinoma in situ of rectum

ICD-10-CM Codes›C00–D49›D00-D09›D01

ICD-10-CM D01.2
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

D01.2 is a billable ICD-10-CM diagnosis code for carcinoma in situ of rectum. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 374 through 376. Coders also document this condition as carcinoma in situ of colon. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Gastrointestinal cancers - colorectal.

Code Identity

ICD-10-CM Code
D01.2
Billable Status
Yes — Valid for Submission
Code Describes
Carcinoma in situ of rectum
Short Description
Carcinoma in situ of rectum
Same as the full description in the CMS dataset.
Parent Code
D01
Carcinoma in situ of other and unspecified digestive organs

Code Classification

ChapterC00–D49Neoplasms
SectionD00-D09In situ neoplasms
CategoryD01Carcinoma in situ of other and unspecified digestive organs
This CodeD01.2Carcinoma in situ of rectum

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Carcinoma in situ of colon
  • Carcinoma in situ of rectosigmoid junction
  • Carcinoma in situ of rectum
  • Carcinoma in situ of rectum and rectosigmoid junction
  • Carcinoma in situ of sigmoid colon
  • Dysplasia of large intestine
  • Dysplasia of rectum
  • Severe dysplasia of rectum

Clinical ClassificationClinical

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

CCSR NEO015
Gastrointestinal cancers - colorectal
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.
rectum (ampulla)C20C78.5D01.2D12.8D37.5D49.0

Patient EducationClinical

Colorectal Cancer

Colorectal cancer is cancer that develops in the tissues of the colon or rectum. Your colon and rectum are part of your digestive system:

The full article covers:

  • What is colorectal cancer?
  • What causes colorectal cancer?
  • Who is more likely to develop colorectal cancer?
  • What are the symptoms of colorectal cancer?
  • What is screening for colorectal cancer and who needs it?
  • How is colorectal cancer diagnosed?
  • What are the treatments for colorectal cancer?
  • Can colorectal cancer be prevented?

Read the full article at MedlinePlus

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

Convert D01.2 to ICD-9-CMHistory

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

ICD-9-CM
230.4 Ca in situ rectum
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 D01.2Overview

Is D01.2 (Carcinoma in situ of other and unspecified digestive organs) a billable code?

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

What MS-DRG does D01.2 group to?

When carcinoma in situ of rectum is the principal diagnosis on an inpatient stay, it groups to MS-DRG 374, 375, 376, with relative weights from 0.9243 to 2.1387 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of D01.2?

Under the General Equivalence Mappings, carcinoma in situ of rectum converts to ICD-9-CM 230.4 (ca in situ rectum). 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.