ICD-10 Code C64.9 – Malignant neoplasm of unspecified kidney, except renal pelvis (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C64.9 – Malignant neoplasm of unspecified kidney, except renal pelvis
What it is
C64.9 identifies a malignant tumor arising in the kidney when the documentation does not specify the side or a more exact kidney site. It excludes cancers of the renal pelvis.
Clinical signs
Clinical features vary; refer to documentation. Commonly recorded findings include a renal mass on imaging, hematuria, flank pain, or incidental discovery during workup for another condition.
When to use this code
Use this code when the provider documents kidney cancer but does not identify the affected kidney or a more specific renal site. It may also fit when the record confirms malignancy of the kidney and laterality is unavailable. If the chart mentions renal pelvis involvement, choose a different code.
Do not use for
Do not use it for malignant neoplasm of the renal pelvis or for a clearly documented right or left kidney cancer. Check documentation if the site is described as renal, hilar, or collecting-system related.
Coding tip
Query for laterality and exact renal site whenever the note says only “kidney cancer.”