Background: There is a paucity of data regarding the challenges associated with the timely and accurate diagnosis of Renal Cell Carcinoma (RCC) and its effective multidisciplinary management. This study aimed to assess the knowledge and skills of healthcare providers (HCPs) managing and coordinating the care of patients with advanced RCC (aRCC) across multidisciplinary teams. Methods: A sequential mixed methods needs assessment was conducted across the United States with medical oncologists (ONCs), nephrologists (NEPHs), physician assistants (PAs), nurse practitioners (NPs), and registered nurses (RNs). Interviews, transcribed and thematically analyzed, and online surveys, statistically analyzed, were triangulated. Results: A total of 305 HCPs completed an interview (n=40) or the survey (n=265): 78 ONCs, 62 NEPHs, 57 PAs, 55 NPs, 53 RNs. One third (33%) of HCPs reported suboptimal skills in adjusting the dose of a treatment for aRCC in the event of adverse reactions. Interviews underscored a lack of clarity for HCPs on when to reduce the dose or when to discontinue and/or switch to other drugs. Suboptimal knowledge and skills related to toxicities were found (Table). Breakdowns in communication across multidisciplinary teams were identified by 46% of HCPs. Of those, 61% occurred when monitoring side effects and 48% when referring to ONCs. Some NEPHs reported never, rarely, or sometimes being involved with ONCs in the management of nephritis (25%), chronic kidney disease (19%), or acute renal failure (24%). Interviews suggested the role of NEPHs in the care of aRCC is poorly recognized and that NEPHs are perceived to have limited time to spend in the care of cancer patients. Few NEPHs reported gaps in knowledge/skills managing key renal complications such as nephritis (13%/15%), chronic kidney disease (6%/15%), and acute renal failure (9%/9%). Conclusions: This study identified a need to improve HCPs’ knowledge of the signs/symptoms of treatment side effects, skills in identifying/referring patients to appropriate specialists, and skills in managing adverse events. Barriers to involving NEPHs in the co-management of aRCC included a lack of recognition of their role in managing treatment-induced renal complications.These results should inform educational interventions for professionals caring for aRCC patients.