C66Header code — not billable

Malignant neoplasm of ureter

Chapter
2. Neoplasms
Category
C66
Effective date
October 1, 2026

Related codes in category C66

C66.1Malignant neoplasm of right ureterYesC66.2Malignant neoplasm of left ureterYesC66.9Malignant neoplasm of unspecified ureterYes

Frequently asked questions

What is ICD-10 code C66?

C66 is an ICD-10-CM diagnosis code for Malignant neoplasm of ureter.

Is C66 a billable code?

No. C66 is a category/header code, not billable on its own — use one of its more specific child codes instead.

What ICD-10-CM chapter is C66 in?

C66 falls under Chapter 2: Neoplasms.

When did C66 become effective?

C66 has been effective since October 1, 2026, per the CMS/CDC ICD-10-CM annual release.

What other codes are related to C66?

C66 belongs to category C66, which includes 3 other codes — see the related codes list on this page.

ICD-10-CM data maintained by CDC/CMS (public domain). Always verify codes with authoritative sources before making coding or billing decisions.