COVID-19大流行对K-12教育造成了巨大的持续干扰。利用540万名3-8年级美国学生的考试成绩，我们追踪了大流行前两年数学和阅读成绩的变化。2021年秋季3-8年级的平均数学考试成绩是.20 -。27 standard deviation (SD) lower relative to same-grade peers in the fall of 2019, while reading test scores decreased by .09–.18 SD. Achievement gaps between students in low-poverty and high-poverty elementary schools grew by .10–.20 SD, primarily during the 2020–2021 school year. Achievement disparities by student race/ethnicity also widened substantively. Observed declines are more substantial than during other recent school disruptions, such as those due to natural disasters.