African Americans and Latinos have less mental health care access and face substantial stigmatization in seeking and receiving treatment for mental health disorders (MHDs), compared to Whites. Untreated MHDs are associated with high mortality rates, increased risks of developing major chronic diseases, including heart disease and diabetes, and accelerating disease progression. Evidence demonstrates the cost effectiveness of improving health care for patients with coexisting MHDs and other diseases through the integration of individual and organizational factors, yet there remains a gap in our knowledge about how to best accomplish the integration of Local Health Departments (LHDs) with the communities they serve. The objective of this study is to identify effective LHD activitie that reduce racial and ethnic disparities in health care for individuals with MHDs, including those with MHDs and coexisting chronic diseases. Our central hypothesis is that LHDs' service provision and health promotion can reduce disparities. Our hypothesis is informed by an ecological model demonstrating that LHDs can reduce health care disparities for individuals with MHDs by providing critical health care resources to people with limited health care access and promoting health education and patient engagement that reflect community health needs. Since LHDs assume more responsibilities in underserved areas and provide a major source of health care for vulnerable populations, racial and ethnic minority patients with MHDs may gain more benefit from LHD activities. Specifically, we will assess the effect of LHD activities on health care for individuals with MHDs (Aim 1), and the effect of LHD activities on racial and ethnic disparities (African American vs. White; Latino vs. White) in mental health care (Aim 2). Given that MHDs are common comorbidities of major chronic diseases, we will assess the effect of LHD activities on racial and ethnic disparities in general health care for individuals with coexisting MHDs and other chronic diseases, such as diabetes and heart disease (Aim 3). We will assemble a unique multi-level (individual-, LHDs-, county-, and state-) data set for the years 2004-2014, and employ multi-level/hierarchical estimation, difference-in-differences analysis, and decomposition technique to quantify the contribution of LHDs' activities to the reduction of racial and ethnic disparities in health care for individuals with MHDs. Results of this exploratory study will generate substantial amounts of new evidence and insights about how to utilize LHDs' resources to integrate the care for individuals with MHDs, and to what extent the resources of LHDs can be used, or should be expanded, to improve mental health. Results of this study will provide preliminary data needed to build a more comprehensive and robust investigation to estimate the impact of LHDs on racial and ethnic disparities in health outcomes, and develop a scientifically sound and culturally tailored LHD-integrated health care model that will improve the efficiency of the health care delivery system and potentially accelerate sustainable efforts to reduce and ultimately eliminate health disparities for individuals with MHDs.