U.S. ICD-10-CM · FY 2027

C66 ICD-10-CM Code: Malignant neoplasm of ureter

A clear reference for the official code description, hierarchy, and related coding information from the FY 2027 U.S. release.

Code definition

Official description

C66

Malignant neoplasm of ureter

ICD-10-CM diagnosis code · United States clinical modification

Classification

Where C66 sits

  1. 1

    Chapter 2

    Neoplasms (C00-D49)

  2. 2

    Section

    Malignant neoplasms of urinary tract (C64-C68)

  3. 3

    Category C66

    Malignant neoplasm of ureter

  4. 4

    Code C66

    Malignant neoplasm of ureter

More specific choices

Codes under C66

C66 is a non-billable category. Choose the child code that best matches the documented diagnosis.

Documentation details

Notes for this code

Inclusion terms

No inclusion terms are listed for C66.

Code first

No “code first” instruction is listed for C66.

Use additional code

No “use additional code” instruction is listed for C66.

Excludes1

Conditions that should not be reported together with this code.

  • malignant neoplasm of ureteric orifice of bladder (C67.6)

Excludes2

Conditions not included here that may be reported separately when present.

No Excludes2 note is listed for C66.

Transparency

Source and release

Data release

U.S. ICD-10-CM · FY 2027

Effective date

Oct 1, 2026

This reference is generated from Vero’s ICD-10-CM description, hierarchy, and code-note dataset. The visible content and structured data share that source.

Review the CDC/NCHS ICD-10-CM source

Code-specific guidance

Frequently asked questions

What does ICD-10-CM code C66 mean?

C66 is the FY 2027 U.S. ICD-10-CM code for “Malignant neoplasm of ureter.”

Is C66 a billable or specific ICD-10-CM code?

No. C66 has more specific child codes in the FY 2027 reference data. Select the code that matches the documentation and confirm the active code set and payer requirements.

Where is C66 located in ICD-10-CM?

C66 is listed in Chapter 2, Neoplasms (C00-D49), within Malignant neoplasms of urinary tract (C64-C68) (C64–C68), under category C66, Malignant neoplasm of ureter.

What coding notes are listed for C66?

No inclusion terms are listed for C66 in this reference record. No code-first instruction is listed. Excludes1 notes: malignant neoplasm of ureteric orifice of bladder (C67.6). No Excludes2 note is listed.

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