ICD10
ICD-10 Code C66: Malignant neoplasm of ureter
Reviewed by HealthAssure Clinical TeamUpdated 26 May 2026
What is this code?
ICD-10 entries help standardize how diagnoses are organized for coding, reporting, analytics, and documentation. This code sits within the broader ICD-10 area for Neoplasms (C00-D49).
When is it used?
- May be used when a clinician documents malignant neoplasm of ureter in a patient's medical record.
- May appear in hospital records, claims, referrals, and clinical documentation.
- This code may act more like a grouping or parent code, so a more specific child code may be used in final documentation when available.
What it does not mean
- A code alone does not explain severity, treatment plan, or outcome.
- A medical code should not be treated as a substitute for a doctor's diagnosis or advice.
- This entry may represent a broader category rather than the most specific billable code.
Code hierarchy
chapter
2Neoplasms (C00-D49)
block
C00-C96Malignant neoplasms
block
C00-C75Malignant neoplasms, stated or presumed to be primary (of specified sites), and certain specified histologies, except neuroendocrine, and of lymphoid, hematopoietic and related tissue
block
C64-C68Malignant neoplasms of urinary tract
currentC64-C68
Official coding notes
Excludes1 (do not code together)
- malignant neoplasm of ureteric orifice of bladder (C67.6)
Where you may see this code
You may see this entry in coding references, medical records, or claims workflows when a broader diagnosis category is being reviewed before a more specific code is chosen.
Related specialists
OncologistGeneral Physician
Related codes
Sibling codes
Mapped diagnoses and classifications
SNOMED_CT 895356000high
Bilateral primary malignant neoplasm of ureters
Source: SNOMED International ICD-10 map
SNOMED_CT 448864006high
Carcinoma of ureter
Source: SNOMED International ICD-10 map
SNOMED_CT 363458004high
Malignant neoplasm of ureter
Source: SNOMED International ICD-10 map
SNOMED_CT 895354002high
Primary malignant neoplasm of left ureter
Source: SNOMED International ICD-10 map
SNOMED_CT 895355001high
Primary malignant neoplasm of right ureter
Source: SNOMED International ICD-10 map
SNOMED_CT 94121005high
Primary malignant neoplasm of ureter
Source: SNOMED International ICD-10 map
Coding guidelines
Compatibility
Legacy code aligns to an official FY 2026 category. Frontend should resolve to the official category page and surface the billable child codes.
Legacy codes
C66
Replacement codes
C66.1 — Malignant neoplasm of right ureterC66.2 — Malignant neoplasm of left ureterC66.9 — Malignant neoplasm of unspecified ureter
Common synonyms
Malignant neoplasm of ureter
Frequently asked questions
About this content
This page is prepared by HealthAssure's clinical team using official coding standards from ICD-10. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.