Background: Locally advanced/metastatic urothelial carcinoma (mUC) has poor prognosis and disproportionately affects the elderly, who often have coexisting illness and limited treatment options. According to the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Bladder Cancer (v3.2023), platinum-based chemotherapy (PBC) followed by avelumab maintenance therapy (maintA, only if there is no progression on first-line [1L] PBC), pembrolizumab (P, for platinum-ineligible), and P in combination with enfortumab vedotin (P+EV, for cisplatin-ineligible) are the preferred regimens. We evaluated real-world treatment patterns and overall survival (OS) among mUC patients during the period between maintA and P-EV approvals in the US. Methods: This retrospective cohort study was conducted using structured and chart review data from iKnowMed (iKM), The US Oncology Network electronic health record database. The cohort included adult mUC patients diagnosed between 30 April 2020 and 30 June 2021. Patients were followed from index date (date of 1L anticancer treatment) through 31 March 2023, last patient record or death, whichever occurred first. MaintA was defined as receiving avelumab after 1L PBC, with no documented progressive disease prior to avelumab start or as maintenance therapy indicated by physician notes. Descriptive statistics were used to report patient characteristics and treatment patterns. Kaplan-Meier analysis was implemented to assess OS. Results: A total of 207 patients initiated 1L treatments. The median age was 74 (range: 46 - 90+) years and 166 (80.2%) were male. Of 207 1L-treated patients, 107 (51.7%) received immune checkpoint inhibitor (ICI) monotherapy, 80 (38.6%) received PBC, and 20 (9.7%) received other treatments. The use of 1L ICI monotherapy increased with age, ranging from 15 (14.0%) among those younger than 65 to 57 (53.3%) among those aged 75 or older. Of patients who received 1L PBC, 28 (35.0%) received ICI maintenance therapy; majority of these (n = 26, 92.9%) received maintA (32.5% of patients received 1L PBC). During the follow-up, 71 (34.3%) patients received 2L treatment and 25 (12.1%) patients received 3L treatment. Majority of patients in 2L settings received antibody drug conjugates (n = 30, 42.2%) or ICI monotherapy (n = 27, 38.0%). Median (95% confidence interval) OS was 12.6 (8.5, 15.1) months for 1L-treated patients overall. Conclusions: Despite many recent advances in the therapy for mUC, these patients had poor prognosis. Notably, many 1L patients did not have the opportunities to receive 2L+ treatment, which demonstrated continuing unmet need for mUC patients. ICI monotherapy continues to be a prevalent option, especially for older patients.