337 Background: Nephroureterectomy (NU) is the standard treatment for upper tract urothelial carcinoma (UTUC). Minimally invasive (MI) laparoscopic or robotic-assisted approaches have been introduced in an effort to reduce morbidity. We performed a population-based study to evaluate contemporary utilization trends, morbidity, and costs associated with NUs in the United States. Methods: Using the Premier Hospital Database (Premier, Inc., Charlotte, NC), a nationally representative discharge database with data from over 600 non-federal hospitals in the United States, we captured patients who underwent a NU (ICD-9 55.51) with diagnoses of renal pelvis (189.1) or ureteral (189.2) neoplasms from 2004 to 2013. We fitted regression models, adjusting for clustering by hospitals and survey weighting to evaluate 90-day postoperative complications, length of stay (LOS), OR time, and direct hospital costs among open, laparoscopic, and robotic NU. Results: The weighted cohort included 17,245 open, 13,298 laparoscopic, and 3,745 robotic NUs. MI surgeries increased from 36% to 54% from 2004 to 2013, while the number of NUs decreased by nearly 20% during the same period (Figure 1). The overall 90-day mortality, major (Clavien 3-5), and minor (Clavien 1-2) complication rates were 1.89%, 9.4%, and 27.7%, respectively, with no statistically significant differences between the three approaches based on adjusted logistic regression analyses. The LOS was decreased for laparoscopic (Incidence Risk Ratio [IRR]: 0.87, 95% CI: 0.82-0.92, p<0.001) and robotic (IRR: 0.76, 95% CI: 0.7-0.83, p<0.001) NU compared to open NU. OR time was 10.35 (p<0.05) and 56.35 (p<0.001) minutes longer for laparoscopic and robotic NU. Adjusted 90-day median direct hospital costs were $1,354 and $3,533 higher for laparoscopic and robotic NU (p<0.001). Conclusions: During this contemporary 10-year study, the use of MI NUs increased to over half of procedures with a recent surge in robotic NUs, along with a concurrent reduction in total NUs performed in the United States. Comparable perioperative outcomes suggest that the morbidity profile may be driven primarily by patient-specific characteristics as opposed to surgical approach.