PROJECT SUMMARY Approximately 10 million Americans are eligible for both Medicare and Medicaid. These dual-eligibles are a disproportionately high-cost population with substantial and often unmet healthcare needs. They are also more likely to be racial/ethnic minorities and experience potentially-preventable hospitalizations and emergency department (ED) visits resulting from disparities in access to primary care. However, relatively little is known about the relationship between primary care access and the broader continuum of potentially-preventable hospital care, which includes not only ED visits and hospitalizations, but also observation stays, 30-day return ED visits, and 30-day all-cause readmissions. Federally qualified health centers (FQHCs) are ?safety net? providers that receive federal funding to provide primary care to underserved populations without regard for patients' ability to pay. FQHCs are known to reduce racial/ethnic disparities in healthcare access and quality, but dual-eligibles' use of FQHCs has not been well studied. Moreover, modifiable organizational characteristics that may explain variations in FQHC performance related to reducing disparities are not well understood. Thus, the objective of this study is to characterize and evaluate the role of FQHCs in providing primary care that lowers rates of?and reduces racial/ethnic disparities in?hospital care among dual-eligibles. The proposed study has three specific aims: 1) To determine the extent to which FQHCs reduce hospital care relative to receiving care from other primary care providers; 2) To determine the extent to which racial/ethnic disparities in hospital care are reduced among FQHC users relative to those receiving care from other primary care providers; and 3) To determine the extent to which organizational characteristics enhance the ability of FQHCs to reduce hospital care and related racial/ethnic disparities in care. Using seven years of Medicare claims data (2012 ? 2018) rates of?and disparities in?hospital care will be modeled as a function of FQHC use and other primary care sources. The extent to which disparities exist within or between FQHCs will also be assessed. Finally, FQHC-specific hospital care rates will be modeled as a function of FQHC characteristics using Medicare claims and FQHC data from the Uniform Data System. The proposed study is significant, because it will provide evidence of the relative effectiveness of FQHCs at lowering rates of?and reducing racial/ethnic disparities in?hospital care and identify modifiable characteristics of high-performing FQHCs for dissemination as best practices. The proposed study is innovative because it is the first to examine the relationship between FQHC use and racial/ethnic disparities in the broader continuum of hospital care among dual-eligibles using quasi-experimental methods (i.e., instrumental variable and difference-in-differences analyses) to address selection bias, and the first to model organizational disparities in hospital care rates across FQHCs as a function of FQHC characteristics. This study is expected to have an immediate positive impact for CMS policymakers, state Medicaid agencies, providers (particularly FQHCs), hospitals, and dual-eligible patients.