2027 ICD-10-CM Diagnosis Code C64.2Malignant neoplasm of left kidney, except renal pelvis
ICD-10-CM Codes›C00–D49›C64-C68›C64
- Billable — Valid for Submission
- CC — Complication or Comorbidity
- Risk Adjusts — HCC 22
- Chronic Condition
C64.2 is a billable ICD-10-CM diagnosis code for malignant neoplasm of left kidney, except renal pelvis. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 656 through 658, 686 through 688. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 27 closely related codes. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Urinary system cancers - kidney.
For Medicare Advantage risk adjustment, C64.2 maps to CMS-HCC Category 22 (Bladder, Colorectal, and Other Cancers) under the V28 model, adding a risk factor of about 0.363 for a community, non-dual, aged beneficiary in payment year 2027.
Code Identity
Code Classification
Medicare Risk Adjustment (HCC)Billing
C64.2 maps to a payment category in the CMS-HCC model used to risk-adjust Medicare Advantage payments. Weights are the published community factors for payment year 2027.
Source: CMS Payment Year 2027 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Bilateral primary malignant neoplasm of kidneys
- Clear cell carcinoma of left kidney
- Nephroblastoma
- Nephroblastoma of left kidney
- Primary leiomyosarcoma of abdomen
- Primary leiomyosarcoma of left kidney
- Primary leiomyosarcoma of retroperitoneum
- Primary malignant neoplasm of left kidney
- Primary malignant neoplasm of right kidney
- Primary nephroblastoma
- Primary nephroblastoma of left kidney
- Primary renal cell carcinoma of left kidney
- Primary sarcoma of left kidney
- Primary sarcoma of retroperitoneum
- Primary transitional cell carcinoma of kidney
- Primary transitional cell carcinoma of left kidney
- Renal cell carcinoma of bilateral kidneys
- Sarcoma of kidney
- Transitional cell carcinoma of left kidney
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to C64.2: its own notes plus those printed at C64 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.
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 C64.2, its category, or a range that includes it.
Applicable To 3
These notes mention C64.2.
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Wilms Tumor
a malignant kidney tumor, caused by the uncontrolled multiplication of renal stem (blastemal), stromal (stromal cells), and epithelial (epithelial cells) elements. however, not all three are present in every case. several genes or chromosomal areas have been associated with wilms tumor which is usually found in childhood as a firm lump in a child's side or abdomen.
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 C64.2 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About C64.2Overview
What is the ICD-10 code for malignant neoplasm of left kidney, except renal pelvis?
The ICD-10-CM code for malignant neoplasm of left kidney, except renal pelvis is C64.2 (sometimes written as C642). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is C64.2 (Malignant neoplasm of kidney, except renal pelvis) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report malignant neoplasm of left kidney, except renal pelvis on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does C64.2 group to?
When malignant neoplasm of left kidney, except renal pelvis is the principal diagnosis on an inpatient stay, it groups to MS-DRG 656, 687, 658, 657, 686, 688, with relative weights from 0.7332 to 3.2782 depending on complications. Higher weights mean higher Medicare reimbursement.
Is C64.2 a CC or MCC?
CMS lists C64.2 as a CC (complication or comorbidity) for FY 2027. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 27 closely related codes in its exclusion list.
Can C64.2 be reported with C7A.093?
Not as a rule. The Excludes1 note at C64, which applies to C64.2, lists "malignant carcinoid tumor of the kidney (C7A.093)". 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 HCC is C64.2?
C64.2 (malignant neoplasm of left kidney, except renal pelvis) maps to CMS-HCC Category 22 (Bladder, Colorectal, and Other Cancers), commonly written as HCC 22, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2027. It mapped to HCC 11 under the retired V24 model. It also maps in the PACE (CMS-HCC V22), ESRD (V21), and ESRD (V24) models. In the Part D prescription drug model it maps to RxHCC 20.
Does C64.2 risk-adjust for Medicare Advantage payment?
Yes. When documented and reported on a Medicare Advantage encounter, C64.2 adds a risk adjustment factor of about 0.363 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.314 to 0.410 depending on the payment segment). A more severe related category (HCC 17, HCC 18, HCC 19, HCC 20, and HCC 21) supersedes it when both are reported. See the full factor table on the HCC 22 category page.
