C66.9 — Malignant neoplasm of unspecified ureter
Is C66.9 billable?
Yes, but C66.9 is an unspecified code. C66.9 is a valid, billable ICD-10-CM code for encounters from October 1, 2026 through September 30, 2027. However, C66.9 is an unspecified or catch-all code. Payers apply additional scrutiny to unspecified codes and many deny them when the medical record supports a more specific option, so check the documentation before selecting C66.9 — the more specific alternatives are listed below.
More specific alternatives
C66.9 at a glance
| Code | C66.9 |
|---|---|
| Description | Malignant neoplasm of unspecified ureter |
| Billable | Yes |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
Which MS-DRGs does C66.9 group to?
C66.9 sits in MDC 11 and helps define the logic of 3 MS-DRGs (version 44, FY2027). Which one a stay actually groups to also depends on procedures and secondary diagnoses.
- 656Kidney and Ureter Procedures for Neoplasm with MCCsurgical
- 657Kidney and Ureter Procedures for Neoplasm with CCsurgical
- 658Kidney and Ureter Procedures for Neoplasm without CC/MCCsurgical
As a secondary diagnosis, C66.9 is a complication or comorbidity (CC), which can move a stay into a higher-paying DRG.
Excludes1 — never code together — inherited from C66
The conditions below can never be reported together with C66.9 on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.
- malignant neoplasm of ureteric orifice of bladder (C67.6)
How long has C66.9 existed?
C66.9 has been in ICD-10-CM since at least FY2016, the earliest fiscal year on record here.
Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.