2026 ICD-10-CM Diagnosis Code C65.9Malignant neoplasm of unspecified renal pelvis

ICD-10-CM Codes›C00–D49›C64-C68›C65

ICD-10-CM C65.9
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

C65.9 is a billable ICD-10-CM diagnosis code for malignant neoplasm of unspecified renal pelvis. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 656 through 658, 686 through 688. Coders also document this condition as carcinoma of renal pelvis. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Urinary system cancers - ureter and renal pelvis.

Code Identity

ICD-10-CM Code
C65.9
Billable Status
Yes — Valid for Submission
Code Describes
Malignant neoplasm of unspecified renal pelvis
Short Description
Malignant neoplasm of unspecified renal pelvis
Same as the full description in the CMS dataset.
Parent Code
C65
Malignant neoplasm of renal pelvis

Code Classification

ChapterC00–D49Neoplasms
SectionC64-C68Malignant neoplasms of urinary tract
CategoryC65Malignant neoplasm of renal pelvis
This CodeC65.9Malignant neoplasm of unspecified renal pelvis

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Carcinoma of renal pelvis
  • Clear cell adenocarcinoma of Mullerian origin of renal pelvis
  • Malignant neoplasm of renal calyx
  • Malignant neoplasm of renal pelvis
  • Malignant neoplasm of ureteropelvic junction
  • Neoplasm of renal calyx
  • Neoplasm of ureteropelvic junction
  • Primary malignant neoplasm of renal pelvis

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR NEO044
Urinary system cancers - ureter and renal pelvis
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Kidney Cancer

You have two kidneys. They are fist-sized organs on either side of your backbone above your waist. The tubes inside filter and clean your blood, taking out waste products and making urine. Kidney cancer forms in the lining of tiny tubes inside your kidneys.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert C65.9 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
189.1 Malig neo renal pelvis
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About C65.9Overview

Is C65.9 (Malignant neoplasm of renal pelvis) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report malignant neoplasm of unspecified renal pelvis on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does C65.9 group to?

When malignant neoplasm of unspecified renal pelvis is the principal diagnosis on an inpatient stay, it groups to MS-DRG 656, 657, 658, 686, 687, 688, with relative weights from 0.7903 to 3.1838 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of C65.9?

Under the General Equivalence Mappings, malignant neoplasm of unspecified renal pelvis converts to ICD-9-CM 189.1 (malig neo renal pelvis). 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.