2027 ICD-10-CM Diagnosis Code D48.4Neoplasm of uncertain behavior of peritoneum
ICD-10-CM Codes›C00–D49›D37-D48›D48
- Billable — Valid for Submission
- Not Chronic
D48.4 is a billable ICD-10-CM diagnosis code for neoplasm of uncertain behavior of peritoneum. 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.
- Leiomyomatosis peritonealis disseminata
- Mesothelioma of mesocolon
- Neoplasm of omentum
- Neoplasm of peritoneum and retroperitoneum
- Neoplasm of rectouterine pouch
- Neoplasm of the mesocolon
- Neoplasm of uncertain behavior of omentum
- Neoplasm of uncertain behavior of parietal peritoneum
- Neoplasm of uncertain behavior of pelvic peritoneum
- Neoplasm of uncertain behavior of peritoneum
- Neoplasm of uncertain behavior of rectouterine pouch
- Neoplasm of uncertain behavior of retroperitoneum
- Neoplasm of uncertain behavior of retroperitoneum and peritoneum
- Neoplasm of uncertain behavior of the mesentery
- Neoplasm of uncertain behavior of the mesocolon
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to D48.4: its own notes plus those printed at D48, 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.
- neurofibromatosis (nonmalignant) (Q85.0-)
- 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 D48.4, its category, or a range that includes it.
Excludes2 1
These codes carry an Excludes2 note naming D48.4: its condition is not part of those codes, and both may be reported when the patient has both.
Notes 1
These notes mention D48.4.
- Block D37-D48 Neoplasms of uncertain behavior, polycythemia vera and myelodysplastic syndromesCategories D37-D44, and D48 classify by site neoplasms of uncertain behavior, i.e., histologic confirmation whether the neoplasm is malignant or benign cannot be made. names D48, which includes this code
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
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. |
|---|---|---|---|---|---|---|
| cavity › peritoneal | C48.2 | C78.6 | – | D20.1 | D48.4 | D49.0 |
| cul-de-sac (Douglas') | C48.1 | C78.6 | – | D20.1 | D48.4 | D49.0 |
| Douglas' cul-de-sac or pouch | C48.1 | C78.6 | – | D20.1 | D48.4 | D49.0 |
| mesentery, mesenteric | C48.1 | C78.6 | – | D20.1 | D48.4 | D49.0 |
| mesoappendix | C48.1 | C78.6 | – | D20.1 | D48.4 | D49.0 |
| mesocolon | C48.1 | C78.6 | – | D20.1 | D48.4 | D49.0 |
| omentum | C48.1 | C78.6 | – | D20.1 | D48.4 | D49.0 |
| peritoneum, peritoneal (cavity) | C48.2 | C78.6 | – | D20.1 | D48.4 | D49.0 |
| peritoneum, peritoneal (cavity) › parietal | C48.1 | C78.6 | – | D20.1 | D48.4 | D49.0 |
| peritoneum, peritoneal (cavity) › pelvic | C48.1 | C78.6 | – | D20.1 | D48.4 | D49.0 |
| peritoneum, peritoneal (cavity) › specified part NEC | C48.1 | C78.6 | – | D20.1 | D48.4 | D49.0 |
| rectouterine pouch | C48.1 | C78.6 | – | D20.1 | D48.4 | D49.0 |
Patient EducationClinical
Peritoneal Disorders
Your peritoneum is the tissue that lines your abdominal wall and covers most of the organs in your abdomen. A liquid, peritoneal fluid, lubricates the surface of this tissue.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert D48.4 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About D48.4Overview
What is the ICD-10 code for neoplasm of uncertain behavior of peritoneum?
The ICD-10-CM code for neoplasm of uncertain behavior of peritoneum is D48.4 (sometimes written as D484). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is D48.4 a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report neoplasm of uncertain behavior of peritoneum on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does D48.4 group to?
When neoplasm of uncertain behavior of peritoneum 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 D48.4 be reported with a code from Q85.0?
Not as a rule. The Excludes1 note at D48, which applies to D48.4, lists "neurofibromatosis (nonmalignant) (Q85.0-)". 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 D48.4?
Under the General Equivalence Mappings, neoplasm of uncertain behavior of peritoneum converts to ICD-9-CM 235.4 (unc behav neo peritoneum). The mapping is approximate, so confirm the match fits the documentation.
