Background: Previous reports have found that NGS testing on stage IV GU cancer patients is performed less commonly than expected based on the prevalence of GU tumors in comparison to other tumor types. In addition, most of the data on NGS testing frequency has been in the academic setting. This study will look at NGS testing in stage IV GU pts in the private practice setting. Methods: In the retrospective portion of the study, we used algorithms in Flatiron’s OncoEMR to identify baseline NGS testing frequency in all stage IV GU cancer patients. In the prospective portion, we used an EP to communicate with doctors about their stage IV GU cancer pts with upcoming appointments. Our primary endpoint was to determine the percentage of stage IV GU pts who had NGS testing; our secondary endpoint was to determine how often NGS testing would provide an alternative therapeutic option. Results: 91 stage IV GU cancer pts were identified retrospectively from 6/1/2020-12/31/2020. 20 (22%) of them had had NGS testing: 12 of 68 (18%) prostate cancer pts, 6 of 13 (46%) bladder cancer pts and 2 of 10 (20%) kidney cancer pts. Prospectively, 65 patients with Stage IV GU cancer and upcoming appointments were identified between 8/23/2021-9/13/2021. 17 (26%) had previously had NGS testing: 10 of 46 (22%) prostate pts, 4 of 9 (44%) bladder pts, and 3 of 10 (30%) kidney pts. The EP prompted additional testing of 10 pts. Of the total 27 pts, 8 (30%) were found to have actionable mutations: 7 of 17 (41%) prostate pts and 1 of 6 (17%) bladder pts. 6 of the 8 actionable mutations were either BRCA1/BRCA2 or PALB2. Conclusions: Our results supported those previously reported in academic settings which found that GU cancers were less likely than other metastatic cancers to have NGS testing performed. Prostate cancer was the least likely of the GU cancers to have NGS testing, however, the findings highlight the importance of germline testing in this population. A longer term study may have further borne out the benefits of EP. Improved communication (huddles, multidisciplinary rounds, etc.) would likely increase compliance with NGS testing as would automated order sets and “hard stops” in the EMR. As trials and standard options for GU cancers increase, physician ordering of NGS will follow. Universal NGS testing should be the goal of all stage IV GU patients to maximize therapeutic options.