2026 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 2026 (October 1, 2025 through September 30, 2026) 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
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
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, 2025 through September 30, 2026.
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 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 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.
Footnotes
[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.
