2027 ICD-10-CM Diagnosis Code D37.4Neoplasm of uncertain behavior of colon
ICD-10-CM Codes›C00–D49›D37-D48›D37
- Billable — Valid for Submission
- Not Chronic
D37.4 is a billable ICD-10-CM diagnosis code for neoplasm of uncertain behavior of colon. 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. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Neoplasms of unspecified nature or uncertain behavior.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Neoplasm of hepatic flexure of colon
- Neoplasm of splenic flexure of colon
- Neoplasm of uncertain behavior of ascending colon
- Neoplasm of uncertain behavior of cecum
- Neoplasm of uncertain behavior of colon
- Neoplasm of uncertain behavior of descending colon
- Neoplasm of uncertain behavior of hepatic flexure of colon
- Neoplasm of uncertain behavior of large intestine
- Neoplasm of uncertain behavior of sigmoid colon
- Neoplasm of uncertain behavior of splenic flexure of colon
- Neoplasm of uncertain behavior of transverse colon
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to D37.4: its own notes plus those printed at D37, block D37-D48, and Chapter 2. A note printed at a category, block or chapter applies to every code under it.
Excludes1
Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.
- stromal tumors of uncertain behavior of digestive system (D48.1-)
- neoplasms of unspecified behavior (D49.-)
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 D37.4, its category, or a range that includes it.
Excludes2 1
These codes carry an Excludes2 note naming D37.4: its condition is not part of those codes, and both may be reported when the patient has both.
- D49 Neoplasms of unspecified behavior
Notes 1
These notes mention D37.4.
- Block D37-D48 Neoplasms of uncertain behavior, polycythemia vera and myelodysplastic syndromes
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
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. |
|---|---|---|---|---|---|---|
| caput coli | C18.0 | C78.5 | D01.0 | D12.0 | D37.4 | D49.0 |
| cecum | C18.0 | C78.5 | D01.0 | D12.0 | D37.4 | D49.0 |
| hepatic [See Also: Index to disease, by histology] › flexure (colon) | C18.3 | C78.5 | D01.0 | D12.3 | D37.4 | D49.0 |
| ileocecum, ileocecal (coil) (junction) (valve) | C18.0 | C78.5 | D01.0 | D12.0 | D37.4 | D49.0 |
| intestine, intestinal › large | C18.9 | C78.5 | D01.0 | D12.6 | D37.4 | D49.0 |
| intestine, intestinal › large › caput coli | C18.0 | C78.5 | D01.0 | D12.0 | D37.4 | D49.0 |
| intestine, intestinal › large › cecum | C18.0 | C78.5 | D01.0 | D12.0 | D37.4 | D49.0 |
| intestine, intestinal › large › colon | C18.9 | C78.5 | D01.0 | D12.6 | D37.4 | D49.0 |
| intestine, intestinal › large › colon › ascending | C18.2 | C78.5 | D01.0 | D12.2 | D37.4 | D49.0 |
| intestine, intestinal › large › colon › caput | C18.0 | C78.5 | D01.0 | D12.0 | D37.4 | D49.0 |
| intestine, intestinal › large › colon › descending | C18.6 | C78.5 | D01.0 | D12.4 | D37.4 | D49.0 |
| intestine, intestinal › large › colon › distal | C18.6 | C78.5 | D01.0 | D12.4 | D37.4 | D49.0 |
| intestine, intestinal › large › colon › left | C18.6 | C78.5 | D01.0 | D12.4 | D37.4 | D49.0 |
| intestine, intestinal › large › colon › pelvic | C18.7 | C78.5 | D01.0 | D12.5 | D37.4 | D49.0 |
| intestine, intestinal › large › colon › right | C18.2 | C78.5 | D01.0 | D12.2 | D37.4 | D49.0 |
| intestine, intestinal › large › colon › sigmoid (flexure) | C18.7 | C78.5 | D01.0 | D12.5 | D37.4 | D49.0 |
| intestine, intestinal › large › colon › transverse | C18.4 | C78.5 | D01.0 | D12.3 | D37.4 | D49.0 |
| intestine, intestinal › large › hepatic flexure | C18.3 | C78.5 | D01.0 | D12.3 | D37.4 | D49.0 |
| intestine, intestinal › large › ileocecum, ileocecal (coil) (valve) | C18.0 | C78.5 | D01.0 | D12.0 | D37.4 | D49.0 |
| intestine, intestinal › large › sigmoid flexure (lower) (upper) | C18.7 | C78.5 | D01.0 | D12.5 | D37.4 | D49.0 |
| intestine, intestinal › large › splenic flexure | C18.5 | C78.5 | D01.0 | D12.3 | D37.4 | D49.0 |
| junction › ileocecal | C18.0 | C78.5 | D01.0 | D12.0 | D37.4 | D49.0 |
| sigmoid flexure (lower) (upper) | C18.7 | C78.5 | D01.0 | D12.5 | D37.4 | D49.0 |
| spleen, splenic NEC › flexure (colon) | C18.5 | C78.5 | D01.0 | D12.3 | D37.4 | D49.0 |
Patient EducationClinical
Colonic Diseases
Your colon, also known as the large intestine, is part of your digestive system. It's a long, hollow tube at the end of your digestive tract where your body makes and stores stool. Many disorders affect the colon's ability to work properly. Some of these include:
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert D37.4 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About D37.4Overview
What is the ICD-10 code for neoplasm of uncertain behavior of colon?
The ICD-10-CM code for neoplasm of uncertain behavior of colon is D37.4 (sometimes written as D374). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is D37.4 a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report neoplasm of uncertain behavior of colon on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does D37.4 group to?
When neoplasm of uncertain behavior of colon 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 D37.4 be reported with a code from D48.1?
Not as a rule. The Excludes1 note at D37, which applies to D37.4, lists "stromal tumors of uncertain behavior of digestive system (D48.1-)". 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 D37.4?
Under the General Equivalence Mappings, neoplasm of uncertain behavior of colon converts to ICD-9-CM 235.2 (unc behav neo intestine). The mapping is approximate, so confirm the match fits the documentation.
