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C65.1 ICD-10-CM Code: Malignant neoplasm of right renal pelvis

C65.1 maps to CMS-HCC V28 22. A source-labeled RAF reference is available. Confirm the documented diagnosis and applicable coding requirements. MEAT criteria · RAF Calculator · free HCC coding tools

ICD-10-CM Code View

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Code lookupC65.1

FY 2026 Apr update / Neoplasms (C00-D49) / Malignant neoplasms of urinary tract (C64-C68)

C65.1

Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidance

Malignant neoplasm of right renal pelvis

Cancer that starts in the right renal pelvis, the funnel-shaped structure inside the kidney that collects and drains urine.

Buddy the Bee presenting code insight

Buddy Insight

Right renal pelvis cancer is a urothelial (transitional cell) carcinoma arising from the renal pelvis lining — the funnel-shaped urine collecting structure inside the kidney.

OverviewRisk ModelsCode BookDocumentationAuditNotesEdition comparison

CMS-HCC V28

HCC 22

Code-level coefficient reference

CMS-HCC V24

Historical

Historical

Not used for CY2026 payment

ACA/HHS

HCC 011

Code-level coefficient reference

ESRD/PACE

HCC 11

Code-level coefficient reference

RXHCC

HCC 20

Code-level coefficient reference

Code Book Path

Official
C65Malignant neoplasm of renal pelvisC65.1Malignant neoplasm of right renal pelvis

Inclusion Terms

Official

No inclusion terms are included in this display for C65.1. Check the code and parent instructions in the Code Book.

Excludes 2

Official

No Excludes 2 notes are included in this display for C65.1. Check the code and parent instructions in the Code Book.

Related Codes

Official
C65.2Malignant neoplasm of left renal pelvisC65.9Malignant neoplasm of unspecified renal pelvis

Includes

Official
  • malignant neoplasm of pelviureteric junctionInherited from C65
  • malignant neoplasm of renal calycesInherited from C65

Excludes 1

Official

No Excludes 1 notes are included in this display for C65.1. Check the code and parent instructions in the Code Book.

Code First

Official

No Code First sequencing instructions are included in this display for C65.1. Check the code and parent instructions in the Code Book.

Use Additional

Official

No Use Additional Code instructions are included in this display for C65.1. Check the code and parent instructions in the Code Book.

Code Also

Official

No Code Also instructions are included in this display for C65.1. Check the code and parent instructions in the Code Book.

Buddy Documentation Tip

HCC Buddy guidance
Pathology confirming malignancy originating in the right renal pelvis
Histologic type (transitional cell/urothelial carcinoma in most cases)
Grade and staging
Imaging confirming the tumor is in the renal pelvis, not the kidney cortex

MEAT Support

HCC Buddy guidance
Pathology confirming malignancy originating in the right renal pelvis
Histologic type (transitional cell/urothelial carcinoma in most cases)
Grade and staging
Imaging confirming the tumor is in the renal pelvis, not the kidney cortex

Audit Caution

HCC Buddy guidance
Confusing renal pelvis cancer (urothelial) with kidney parenchyma cancer (renal cell) — they require different codes and have different histologies
Coding kidney cancer extending into the renal pelvis as C65.x instead of C64.x (code the primary origin)
Using unspecified laterality when imaging clearly shows right side
Not recognizing that upper tract urothelial carcinoma requires surveillance of the contralateral tract and bladder

Common Mistakes

HCC Buddy guidance
C64.1 — Right kidney cancer; the kidney parenchyma and renal pelvis are different anatomical sites with different histologies
C65.2 — Left renal pelvis; verify laterality
C65.9 — Unspecified renal pelvis; use C65.1 when right is documented
C66.1 — Right ureter cancer; renal pelvis and ureter are contiguous but coded separately

Current with CMS: FY2026 ICD-10-CM Apr 1 update (effective Apr 1 – Sep 30, 2026) · CMS-HCC V28, 100% phased in for payment year 2026. FY2027 code set already staged for October 1, 2026. How HCC Buddy stays current →

Is C65.1 an HCC code?

Yes. C65.1 (Malignant neoplasm of right renal pelvis) maps to HCC 22, Bladder, Colorectal, and Other Cancers under the CMS-HCC V28 risk adjustment model, with a source-labeled community non-dual aged reference coefficient of 0.363. Source-labeled code-level coefficients are references, not member totals. Actual contribution depends on complete member context, hierarchy and cleanup rules, interactions, and model year. HCC Buddy's RAF Calculator supports CMS-HCC V28 PY2026 and shows no score unless every required source and calculation check passes. It is billable for payment year 2026.

Coder answer: C65.1 is billable and maps to V28 HCC 22, Bladder, Colorectal, and Other Cancers. Open it in the Code Book for the tabular path, RAF, and MEAT checklist.

Code
C65.1
Description
Malignant neoplasm of right renal pelvis
HCC (V28)
HCC 22 — Bladder, Colorectal, and Other Cancers
RAF reference coefficient
0.363
Billable
Yes
Payment year
2026

HCC Category Mapping

V28HCC 22, Bladder, Colorectal, and Other Cancers
0.363
ESRDHCC 11, Colorectal/Bladder/and Other Cancers
Not separately weighted
RxHCCHCC 20, Lung, Kidney, and Other Cancers; Secondary Cancer of Lymph Nodes and Other Sites
Not separately weighted

These are source-labeled model coefficients, not member totals. A category may still be removed by hierarchy or model cleanup rules. Weights are not directly comparable across models: CMS-HCC V28 and V24 use Community, Non-Dual, Aged; ESRD uses the dialysis continuing-enrollee model; RxHCC is the Part D continuing-enrollee, non-low-income, aged weight (a larger scale than CMS-HCC). ACA/HHS has no single weight — it varies by metal level. Actual per-patient RAF contribution depends on member context, hierarchy and cleanup rules, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains available for historical review.

Work C65.1 in the Code Book — tabular path, V28 RAF reference, and MEAT checklist →

MEAT review for C65.1

For C65.1, confirm that the documentation supports the diagnosis and meets the applicable coding, encounter, program and payer requirements. MEAT (Monitor, Evaluate, Assess, or Treat) is a review mnemonic, not a universal CMS coding rule.

  • MMonitor: signs, symptoms, disease progression, or lab trending documented in the note
  • EEvaluate: test results, medication response, or physical findings reviewed by the provider
  • AAssess: explicit mention in the assessment or plan with acknowledgment of status
  • TTreat: medication, referral, procedure, therapy, or counseling tied to the diagnosis

Coder workflow notes

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What This Code Means

C65.1 is the ICD-10-CM diagnosis code for malignant neoplasm of right renal pelvis. Cancer that starts in the right renal pelvis, the funnel-shaped structure inside the kidney that collects and drains urine. C65.1 sits in the ICD-10-CM chapter for neoplasms (c00-d49), within the section covering malignant neoplasms of urinary tract (c64-c68).

Under the CMS-HCC V28 risk adjustment model, C65.1 maps to Bladder, Colorectal, and Other Cancers (HCC 22) with a source-labeled community, non-dual, aged reference coefficient of 0.363. No V24 mapping is shown for C65.1; use the applicable model and payment year when reviewing the V28 mapping. For CY2026 non-PACE Medicare Advantage, CMS uses 100% of the 2024 CMS-HCC model (V28). PACE uses a separate model blend. Source-labeled code-level coefficients are references, not member totals. Actual contribution depends on complete member context, hierarchy and cleanup rules, interactions, and model year. HCC Buddy's RAF Calculator supports CMS-HCC V28 PY2026 and shows no score unless every required source and calculation check passes.

Distinguish this from C64.1 by confirming the tumor originates in the renal pelvis, not the kidney parenchyma. For C65.1, confirm that the documentation supports the diagnosis and meets the applicable coding, encounter, program and payer requirements. MEAT (Monitor, Evaluate, Assess, or Treat) is a review mnemonic, not a universal CMS coding rule. When documentation is ambiguous, coders should issue a provider query rather than assume the highest-specificity variant.

HCC Buddy maintains structured V28 and V24 mapping, source-labeled coefficient references, and MEAT documentation criteria for C65.1 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

  • •Distinguish this from C64.1 by confirming the tumor originates in the renal pelvis, not the kidney parenchyma
  • •Verify laterality documentation specifies 'right' kidney

Clinical Significance

Right renal pelvis cancer is a urothelial (transitional cell) carcinoma arising from the renal pelvis lining — the funnel-shaped urine collecting structure inside the kidney. This is classified as an upper tract urothelial carcinoma and has a different biology and treatment approach than renal cell carcinoma of the kidney parenchyma. Distinguishing renal pelvis from kidney parenchyma cancer is a critical coding distinction.

Documentation Requirements

  • ✓Pathology confirming malignancy originating in the right renal pelvis
  • ✓Histologic type (transitional cell/urothelial carcinoma in most cases)
  • ✓Grade and staging
  • ✓Imaging confirming the tumor is in the renal pelvis, not the kidney cortex
  • ✓Urine cytology results if performed
  • ✓Treatment plan (nephroureterectomy is the standard approach)

Commonly Confused Codes

  • •C64.1: Right kidney cancer; the kidney parenchyma and renal pelvis are different anatomical sites with different histologies
  • •C65.2: Left renal pelvis; verify laterality
  • •C65.9: Unspecified renal pelvis; use C65.1 when right is documented
  • •C66.1: Right ureter cancer; renal pelvis and ureter are contiguous but coded separately

Child Codes

C65.1Malignant neoplasm of right renal pelvis
HCC 22
C65.2Malignant neoplasm of left renal pelvis
HCC 22
C65.9Malignant neoplasm of unspecified renal pelvis
HCC 22

Code Hierarchy

└C65Malignant neoplasm of renal pelvis└C65.1Malignant neoplasm of right renal pelvis
└C65.1Malignant neoplasm of right renal pelvis

For C65.1, confirm that the documentation supports the diagnosis and meets the applicable coding, encounter, program and payer requirements. MEAT (Monitor, Evaluate, Assess, or Treat) is a review mnemonic, not a universal CMS coding rule.

C65.1 maps to CMS-HCC V28 category 22, Bladder, Colorectal, and Other Cancers. See the ICD-10 to HCC mapping hub for how the V28 crosswalk works. The mapping identifies a payment HCC category for C65.1. Review its source-labeled HCC coefficient above, check the RAF Calculator with complete member context for CMS-HCC V28 PY2026, and confirm the documentation the chart needs before the code is submitted. HCC Buddy shows no RAF score unless every required source and calculation check passes.

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Open C65.1 in the Code Book for the full Index-to-Tabular path, MEAT checklist, and V28 HCC mapping, or in the Encoder to code from a keyword search. Pro includes 7 days to try everything, no card required.

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