Health Equity and Accountability Act of 2020 This bill directs the Department of Health and Human Services (HHS) and others to undertake efforts to reduce health disparities. For example, the bill (1) requires more detailed reporting of demographic and health disparities data, (2) directs certain components of HHS to support health workforce diversity, and (3) increases access to culturally and linguistically appropriate health care. The bill also modifies eligibility and other requirements for Medicare, Medicaid, private health insurance, and other programs to reduce health disparities among vulnerable populations. The bill includes specific provisions with respect to noncitizens; maternal, infant, and child health; mental and behavioral health; and specified conditions that disproportionately affect racial and ethnic minority groups, such as certain cancers, HIV/AIDs, kidney disease, and diabetes. Additionally, the bill (1) revises health information technology programs to address health disparities; (2) establishes an Office of Health Disparities within HHS, as well as civil rights compliance offices within HHS agencies; and (3) supports health impact assessments and other efforts pertaining to environmental justice and social determinants of health. The Government Accountability Office must report on health workforce diversity and other specified issues related to health care and health disparities.