School districts nationally reported spending a combined total of nearly $60 billion in Elementary and Secondary School Emergency Relief (ESSER) funds through school year 2021-22, according to GAO's analysis of the Department of Education's (Education) data. About 80 percent of ESSER spending through school year 2021-22 went to addressing students' academic, social, and emotional needs and continuing school operations. For example, most of the districts GAO visited added instructional time and many purchased new curricula. The remaining 20 percent went to addressing physical and mental health concerns, including purchasing cleaning supplies, improving ventilation, and hiring school psychologists. The Government Accountability Office was asked to review how school districts used their ESSER funds. This report addresses (1) how the nation's school districts spent ESSER funds; (2) factors selected districts considered when prioritizing spending; and (3) how selected districts gauge the effects of their spending and how they are planning for the end of ESSER funding. GAO analyzed Education's ESSER spending data for school years 2020-21 and 2021-22 (most recent data available) nationally and by district characteristics. GAO also conducted site visits to 17 school districts across California, Florida, Michigan, New York, Pennsylvania, and Texas to provide illustrative examples of state and district decision-making regarding ESSER spending. These six states collectively received more than 40 percent of all ESSER funds. GAO selected school districts for variety in urbanicity, enrollment, total ESSER funds received, and student demographics. GAO also reviewed relevant reports from and conducted interviews with Education and national organizations actively monitoring ESSER spending.