Racial and ethnic health disparities and inequities can only be eliminated if high-quality information is available by which to track immediate problems and the underlying social determinants of health. Such information can guide the design and application of culturally specific approaches to medicine and public health. Often, health outcomes are disaggregated only by broad racial and ethnic categories such as White, Black, or Hispanic. However, the great, and growing, diversity of the American population means that people’s actual experiences are much more specific. This project was a multifaceted investigation of the leading issues and opportunities for disaggregating data by race and ethnicity for use in furthering health equity. It recommends changes and improvements to the conduct of research and data collection and to the government and corporate policies that define priorities and allocate resources. This report was supported by the Robert Wood Johnson Foundation.