MANY RACIAL AND ETHNIC MINORITIES, PEOPLE with limited English-language proficiency, people with disabilities, and other commonly underserved populations face unique health challenges, have reduced access to health care and insurance, and often experience poorer health throughout their lives. In the past, identifying disparities and effectively monitoring efforts to reduce them have been limited by a lack of specificity, uniformity, and quality in data collection and reporting procedures. The importance in the documentation of disparities and the critical importance of rich data systems to understand and track interventions to reduce health disparities among population subgroups have been called for, dating back to the 1985 Report of the Secretary’s Task Force on Black and Minority Health and the recent Institute of Medicine report Race, Ethnicity, and Language Data: Standardization for Health Care Quality Improvement. As noted in those reports, consistent methods for collecting and reporting health data will help better characterize the nature of health problems in underserved populations. The Department of Health and Human Services (HHS) has adopted new data standards for the collection of race, ethnicity, sex, primary language, and disability status for selfreported data collected from population-based health surveys. Data standards were developed in accordance with section 4302 of the Affordable Care Act. That section of the act focuses on the standardization as well as collection, analysis, and reporting of health disparities data. It requires the HHS secretary to establish data collection standards for race, ethnicity, sex, primary language, and disability status. The law requires that, once established, these data collection standards be used in national population health surveys. The law also gives the secretary the authority to require collection of additional demographic data on departmental population health surveys and to develop appropriate additional data collection standards. Even though data collection will not reduce disparities, having such data is fundamental to the department’s efforts to understand the causes of health disparities, design effective responses, and evaluate progress in reducing disparities. The new data standards for race, ethnicity, sex, primary language, and disability status represent a critical step in uniformly collecting data needed to track disparities and to ensure continued progress in efforts to reduce disparities.