The Bureau of Primary Health Care (BPHC), in the Health Resources and Services Administration (HRSA), funds over 1,100 health centers to provide primary and preventive care to about 19 million underserved patients throughout the nation (Health Resources and Services Administration). Under Section 330 of the Public Health Service Act, the federal Health Center Program has been serving vulnerable populations since 1965 and has been championed as a model delivery system for improving access to care and reducing disparities (Shi et al. 2001a,b; Shi et al. 2004, 2009; Proser 2005; Hadley, Cunningham, and Hargraves 2006; Shi, Stevens, and Politzer 2007). The year 2008 marked the beginning of a program-wide clinical quality improvement initiative to measure and demonstrate quality of care across all BPHC-funded health centers (Health Resources and Services Administration). As part of this initiative, the Health Center Program now incorporates an array of performance measures into its annual data reporting activities, emphasizing a combination of indicators measuring both processes of care and health outcomes. The performance measures tracked by HRSA are consistent with those endorsed by the National Quality Forum, AQA Alliance (formerly the Ambulatory Care Quality Alliance), and other national quality organizations; are designed to address priority health conditions of HRSA safety-net populations throughout the life cycle; and are amenable to quality improvement. For instance, quality measures include indicators of screening for cervical cancer, which disproportionately affects vulnerable populations served by HRSA-funded health centers and for which early detection and care can significantly decrease mortality and improve 5-year survival. Other measures include access to prenatal care, low birth weight, age-appropriate immunizations, and chronic disease management indicators for diabetes and hypertension. In years past, a number of studies have evaluated health centers' performance on quality-related indicators. This prior research found that health centers performed quite well with respect to prenatal care outcomes; specifically, rates of low birth weight in health centers were comparable or lower than other provider settings nationwide, despite the fact that health centers serve higher-risk groups (Politzer et al. 2001; Regan et al. 2003; Haq 2007). In addition, cervical cancer screening rates in health centers exceeded national rates, overall and for specific racial/ethnic and insurance groups (Regan, Lefkowitz, and Gaston 1999; Politzer et al. 2001; Regan et al. 2003; Shi and Stevens 2007; Dor et al. 2008; Shin et al. 2008; Shi et al. 2009). Health centers have also generally shown comparable performance in terms of childhood immunization rates (Schempf, Politzer, and Wulu 2003). However, past research found room for improvement in performance in the management of chronic diseases. Studies of health center patients conducted 10 years ago suggested that only about 50 percent of patients with hypertension, and 40–60 percent of patients with diabetes, received appropriate care (Chin et al. 2000; Hicks et al. 2006). Quality improvement efforts, such as the various Health Disparities Collaboratives implemented within health centers, showed progress in diabetes-related prevention, screening, treatment, and monitoring activities, as well as cancer screening, while the collaboratives were in operation; however, no improvements were demonstrated in hypertension (Chin et al. 2004, 2007; Chien, Walters, and Chin 2007; Landon et al. 2007). There was also mixed evidence regarding the impact of these interventions on longer-term patient outcomes, such as control of glycated hemoglobin levels for diabetes and control of blood pressure for hypertension (Chien, Walters, and Chin 2007; Landon et al. 2007). While informative, these studies may not serve as the best preface to the current state of clinical quality in health centers. Prior data sources date back at least 5 years, preceding the current quality improvement initiative at HRSA, and previous analyses often included regional rather than national data, possibly limiting the generalizability of the findings. To address this gap in the health center literature, this study sought to provide the most recent national analyses of clinical quality performance across health centers, using 2009 Uniform Data System (UDS) data from HRSA. While informative, these studies may not serve as the best preface to the current state of clinical quality in health centers. Prior data sources date back at least 5 years, preceding the current quality improvement initiative at HRSA, and previous analyses often included regional rather than national data, possibly limiting the generalizability of the findings. To address this gap in the health center literature, this study sought to provide the most recent national analyses of clinical quality performance across health centers, using 2009 Uniform Data System (UDS) data from HRSA. While informative, these studies may not serve as the best preface to the current state of clinical quality in health centers. Prior data sources date back at least 5 years, preceding the current quality improvement initiative at HRSA, and previous analyses often included regional rather than national data, possibly limiting the generalizability of the findings. To address this gap in the health center literature, this study sought to provide the most recent national analyses of clinical quality performance across health centers, using 2009 Uniform Data System (UDS) data from HRSA. While informative, these studies may not serve as the best preface to the current state of clinical quality in health centers. Prior data sources date back at least 5 years, preceding the current quality improvement initiative at HRSA, and previous analyses often included regional rather than national data, possibly limiting the generalizability of the findings. To address this gap in the health center literature, this study sought to provide the most recent national analyses of clinical quality performance across health centers, using 2009 Uniform Data System (UDS) data from HRSA. While informative, these studies may not serve as the best preface to the current state of clinical quality in health centers. Prior data sources date back at least 5 years, preceding the current quality improvement initiative at HRSA, and previous analyses often included regional rather than national data, possibly limiting the generalizability of the findings. To address this gap in the health center literature, this study sought to provide the most recent national analyses of clinical quality performance across health centers, using 2009 Uniform Data System (UDS) data from HRSA. While informative, these studies may not serve as the best preface to the current state of clinical quality in health centers. Prior data sources date back at least 5 years, preceding the current quality improvement initiative at HRSA, and previous analyses often included regional rather than national data, possibly limiting the generalizability of the findings. To address this gap in the health center literature, this study sought to provide the most recent national analyses of clinical quality performance across health centers, using 2009 Uniform Data System (UDS) data from HRSA. The purpose of this study was to provide a description of the current status of clinical quality among the nation's health centers, to compare the status with similar national measures, and to examine health center patient, provider, and institutional characteristics associated with performance excellence. We utilized 2009 data from the UDS, to which all health centers are required to submit a variety of aggregated information on an annual basis. Other studies have often included nonrandom and/or regional samples of health centers, but use of the UDS data enables the calculation of national estimates. Finally, previous studies tended to focus on processes of care as indicators of quality rather than both processes of care and health outcomes.