2026 ICD-10-CM Diagnosis Code C48.8Malignant neoplasm of overlapping sites of retroperitoneum and peritoneum
ICD-10-CM Codes›C00–D49›C45-C49›C48
- Billable — Valid for Submission
- Chronic Condition
C48.8 is a billable ICD-10-CM diagnosis code for malignant neoplasm of overlapping sites of retroperitoneum and peritoneum. 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 of peritoneum. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Gastrointestinal cancers - all other types and Gastrointestinal cancers - peritoneum.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Carcinoma of peritoneum
- Malignant neoplasm of peritoneum and retroperitoneum
- Neoplasm of peritoneum and retroperitoneum
- Overlapping malignant neoplasm of retroperitoneum and peritoneum
- Primary adenocarcinoma of overlapping sites of retroperitoneum, peritoneum and omentum
- Primary adenocarcinoma of peritoneum
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. |
|---|---|---|---|---|---|---|
| peritoneum, peritoneal (cavity) › overlapping lesion | C48.8 | – | – | – | – | – |
Patient EducationClinical
Cancer
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Convert C48.8 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About C48.8Overview
Is C48.8 (Malignant neoplasm of retroperitoneum and peritoneum) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report malignant neoplasm of overlapping sites of retroperitoneum and peritoneum on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does C48.8 group to?
When malignant neoplasm of overlapping sites of retroperitoneum and peritoneum 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 C48.8?
Under the General Equivalence Mappings, malignant neoplasm of overlapping sites of retroperitoneum and peritoneum converts to ICD-9-CM 158.8 (mal neo peritoneum NEC). 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.
