BACKGROUND: Socioeconomic factors can have a significant impact on a patient's health status and could be responsible for as much as 70%-80% of a patient's overall health. These factors, called the social determinants of health (SDoH), define a patient's day-to-day experiences. While the influence of such factors is well recognized, who ultimately is responsible for addressing SDoH in health care remains unclear. Physicians and other clinicians are suitably placed to assess SDoH factors that can impact clinical decision making. Understanding Medicare Advantage (MA)-contracted primary care provider (PCP) SDoH perceptions has yet to be fully explored. OBJECTIVES: To (a) understand MA-contracted PCP perceptions of SDoH and (b) investigate correlations between PCP perceptions and their CMS Part D star performances, as well as their hospital admissions and emergency room admissions. METHODS: Survey data were collected from MA-contracted PCPs serving a South Texas market during 2019. An 8-item survey consisting of short answer, ranking, and multiple-choice questions was deployed at attendance-mandatory provider meetings from August to October. Analyses were conducted to understand the providers' SDoH perceptions. PCP responses were first summarized as frequencies and percentages. Baseline descriptive characteristics of the providers were compared by Medicare star ratings using chi-square tests (for categorical variables) and t-tests (for continuous variables). Group differences in physician beliefs on how SDoH affects patients' overall health (question 1), as well as provider beliefs regarding how SDoH affects patients' medication adherence practices (question 2), were assessed using chi-square and t-tests. Associations of provider SDoH perceptions with hospital admissions and emergency room admissions were also assessed. A Fischer's chi-square test was used to examine associations between how PCPs answered the question regarding lack of consistent transportation (question 3) and emergency room admissions. The relationships between PCP perceptions of whose job it is to address SDoH (question 7) and hospital admissions were also evaluated. RESULTS: The response rate for returned surveys was 89%. Analysis revealed that the top 3 barriers were financial insecurity (24.87%), low health literacy (18.65%), and social isolation (15.03%). However, about 36% of PCPs felt they should be the primary addressor of SDoH. There was a significant association between years of practice and CMS Part D star ratings (P = 0.005). A significant association between responses in belief towards patients' overall health and CMS Part D star ratings was examined (P = 0.047). There was a statistically significant difference in mean hospital admissions with PCP perception of who should address SDOH (P = 0.03). Emergency room admissions was significantly associated with perceptions regarding lack of consistent transportation (P = 0.04). No differences with star ratings were observed. CONCLUSIONS: Previous literature recognize safety and food insecurity as key SDoH barriers. However, they were not among the top SDoH barriers in our survey. Future research should examine patient perceptions of SDoH in this population to identify ways providers can better serve their patients. DISCLOSURES: Funding for this study was provided by CareAllies, a Cigna business. Statistical analysis was completed in partnership with the University of Houston. Payne, Esse, Qian, Serna, Villarreal, and Becho-Dominguez are employees of CareAllies. Mohan and Abughosh are employed by the University of Houston College of Pharmacy. Abughosh reports grants from Valeant and Regeneron/Sanofi, unrelated to this work. Vadhariya has nothing to disclose. This research was presented virtually at the AMCP Pharmacist Virtual Learning Days event, April 2020, as well as the American College of Clinical Pharmacy Virtual Poster Symposium, May 26-27, 2020.