2027 ICD-10-CM Diagnosis Code D01.1Carcinoma in situ of rectosigmoid junction
ICD-10-CM Codes›C00–D49›D00-D09›D01
- Billable — Valid for Submission
- Chronic Condition
D01.1 is a billable ICD-10-CM diagnosis code for carcinoma in situ of rectosigmoid junction. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) 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
Code Classification
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
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to D01.1: its own notes plus those printed at D01, block D00-D09, and Chapter 2. A note printed at a category, block or chapter applies to every code under it.
Includes
Further defines, or gives examples of, the content of the category.
- Bowen's disease
- erythroplasia
- grade III intraepithelial neoplasia
- Queyrat's erythroplasia
Excludes1
Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.
Notes
General instructions on how these codes are used.
- 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).
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Referenced in Other NotesGuidance
Instructional notes printed at other codes that name D01.1, its category, or a range that includes it.
Applicable To 1
These notes mention D01.1.
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Rectosigmoid Carcinoma In Situ
an intraepithelial carcinoma arising from the rectosigmoid junction without evidence of invasion.
Table of NeoplasmsClinical
Anatomical sites in the Table of Neoplasms that reference this code family.
| Site | Malig. Primary | Malig. Secondary | Ca in situ | Benign | Uncertain | Unspec. |
|---|---|---|---|---|---|---|
| colon [See Also: Neoplasm, intestine, large] › with rectum | C19 | C78.5 | D01.1 | D12.7 | D37.5 | D49.0 |
| intestine, intestinal › large › colon › and rectum | C19 | C78.5 | D01.1 | D12.7 | D37.5 | D49.0 |
| junction › pelvirectal | C19 | C78.5 | D01.1 | D12.7 | D37.5 | D49.0 |
| junction › rectosigmoid | C19 | C78.5 | D01.1 | D12.7 | D37.5 | D49.0 |
| pelvirectal junction | C19 | C78.5 | D01.1 | D12.7 | D37.5 | D49.0 |
| rectosigmoid (junction) | C19 | C78.5 | D01.1 | D12.7 | D37.5 | D49.0 |
| rectum (ampulla) › and colon | C19 | C78.5 | D01.1 | D12.7 | D37.5 | D49.0 |
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 D01.1 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About D01.1Overview
What is the ICD-10 code for carcinoma in situ of rectosigmoid junction?
The ICD-10-CM code for carcinoma in situ of rectosigmoid junction is D01.1 (sometimes written as D011). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is D01.1 (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 rectosigmoid junction on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does D01.1 group to?
When carcinoma in situ of rectosigmoid junction is the principal diagnosis on an inpatient stay, it groups to MS-DRG 375, 374, 376, with relative weights from 0.8925 to 2.1101 depending on complications. Higher weights mean higher Medicare reimbursement.
Can D01.1 be reported with a code from D03?
Not as a rule. The Excludes1 note at D01, which applies to D01.1, lists "melanoma in situ (D03.-)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).
What is the ICD-9 equivalent of D01.1?
Under the General Equivalence Mappings, carcinoma in situ of rectosigmoid junction converts to ICD-9-CM 230.4 (ca in situ rectum). The mapping is approximate, so confirm the match fits the documentation.
