OBJECTIVE To examine the patient, tumor, and temporal factors associated with receipt of renal mass biopsy (RMB) in a contemporary nationally representative sample. METHODS We queried the Surveillance, Epidemiology, and End Results-Medicare data set for incident cases of renal cell carcinoma diagnosed between 1992 and 2007. We tested for associations among receipt of RMB and patient and tumor characteristics, type of therapy, and procedure type. Temporal trends in receipt of RMB were characterized over the study period. RESULTS Approximately 1 in 5 (20.7%) patients diagnosed with renal cell carcinoma (n = 24,702) underwent RMB before instituting therapy. There was a steady and modest increase in RMB utilization, with the highest utilization (30%) occurring in the final study year. Of patients who underwent radical (n = 15,666) or partial (n = 2211) nephrectomy, 17% and 20%, respectively, underwent RMB in advance of surgery. Sixty-five percent of patients who underwent ablation (n = 314) underwent RMB before or in conjunction with the procedure. Roughly half of patients (50.4%) treated with systemic therapy alone underwent RMB. Factors independently associated with use of RMB included younger age, black race, Hispanic ethnicity, tumor size <7 cm, and metastatic disease at presentation. CONCLUSION At present, most patients who eventually undergo radical or partial nephrectomy do not undergo RMB, whereas most patients who eventually undergo ablation or systemic therapy do. The optimal use of RMB in the evaluation of kidney tumors has yet to be determined.