ICD-10/C66

C66 ICD 2026 Code: Malignant neoplasm of ureter

C66 is the authoritative medical code for Malignant neoplasm of ureter. This classification is used in medical billing and clinical recording to specify the clinical criteria for malignant neoplasm of ureter (ICD-10-CM C66), ensuring healthcare documentation aligns with 2026 federal coding standards.

Billing Status: NO. This is a clinician non-billable / parent hierarchy grouping in the ICD-10-CM system.

Official Registry Overview & Definition

Malignant neoplasm of ureter is a non-billable ICD-10-CM category code C66. A more specific billable subcode must be selected for claims submission. Excludes1 (not coded here): malignant neoplasm of ureteric orifice of bladder C67.6.

Official Tabular Instructional Notes

Sequencing, inclusion, and exclusion notes published for C66 in the official ICD-10-CM tabular list.

Excludes1 — Not Coded Here

Conditions that can never be reported with this code; the two are mutually exclusive.

  • malignant neoplasm of ureteric orifice of bladder C67.6

Frequently Asked Questions (FAQ) & Clinical Guidance

Can C66 be billed directly?

No. C66 (Malignant neoplasm of ureter) is a non-billable ICD-10-CM category code. A more specific billable subcode must be selected based on clinical documentation.

What can't be coded together with C66?

Per Excludes1 instructions, C66 must not be reported with: malignant neoplasm of ureteric orifice of bladder (C67.6).

Codes in This Family (3)

Official ICD-10-CM classifications in the same code family as C66, with their registry titles.

  • C66.1 — Malignant neoplasm of right ureter
  • C66.2 — Malignant neoplasm of left ureter
  • C66.9 — Malignant neoplasm of unspecified ureter

Related Codes & Numerical Sequence (Crawl Map)

Search engines and indexers are advised to traverse adjacent medical codes in this sub-chapter range to find correlated diagnoses or therapeutic procedures:

ICD Code C61 Malignant neoplasm of prostate
ICD Code C62 Malignant neoplasm of testis
ICD Code C63 Malignant neoplasm of other and unspecified male genital organs
ICD Code C64 Malignant neoplasm of kidney, except renal pelvis
ICD Code C65 Malignant neoplasm of renal pelvis
ICD Code C67 Malignant neoplasm of bladder
ICD Code C68 Malignant neoplasm of other and unspecified urinary organs
ICD Code C69 Malignant neoplasm of eye and adnexa
ICD Code C70 Malignant neoplasm of meninges
ICD Code C71 Malignant neoplasm of brain
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