The recently released National Assessment of Educational Progress (NAEP) results show a stark lack of progress since the pandemic—and a continuation of the stagnation and decline that began about a decade earlier. Mirroring the rest of the nation, California’s NAEP scores continued to fall in 2024:  29% of 4th-graders were proficient in reading and 35% in math; among 8th-graders, 28% were proficient in reading and 25% were proficient in math. A closer look at recent NAEP declines and a similar analysis of the state’s own standardized test—the SBAC—brings an important trend into sharper focus: a growing divergence between the highest- and lowest-performing students.

Measuring performance relative to typical grade-to-grade achievement growth across the two exams, we find that both the NAEP and SBAC show substantial progress for high-performing students and stagnation for those with the lowest scores over the last ten years. This was a reversal of the trend in the decade before that.

From 2003 to the early 2010s, students with scores in the bottom 10th percentile saw substantially more progress averaged across all grades and subjects: their scores rose nearly a full grade level, compared to two-thirds of a grade for students near the median and about half a grade for those in the 90th percentile.

By 2019, however, the highest-performing students had gained another half grade level, while the lowest-scoring students saw their performance slip by about a third of a grade. The results for the SBAC, which was introduced in 2015, show a similar trend: early progress for the 50th and 90th percentiles but persistent declines for students at the 10th percentile.

The gap between high- and low-performers widened during the pandemic. While scores on both exams fell at all levels between 2019 and 2022, declines were not as dramatic among high-scoring students. In 2024, scores rose for those at the 90th percentile—roughly reversing initial pandemic learning losses. But for those at the 10th percentile, NAEP and SBAC declines continued and even accelerated.

Taken together, NAEP and SBAC results paint a picture of diverging academic progress between the state’s highest- and lowest-scoring students. The consistency of the results across the two tests is especially notable given the differences between them. The NAEP is administered every two to three years to just a subset of students in grades 4 and 8, while the SBAC covers students in all schools across more grades—from 3–8 and in 11 as well. Further, SBAC is based on the Common Core standards, which have diverged from the NAEP over time.

Evidence shows that the Local Control Funding Formula’s (LCFF’s) targeted spending for high-need students—a group that is disproportionately, but not exclusively, represented among low-performers—has improved outcomes. But LCFF funding is not always allocated to the students and school sites with the greatest challenges. Further, substantial pandemic stimulus dollars have been shown to have only modest effects, and post-pandemic academic progress has been impeded by persistently high rates of chronic absenteeism.

These trends are sobering. But NAEP results from the recent past show that California’s education system has seen sustained periods of broad educational growth. Replicating that past success will be key as policymakers and practitioners attempt to move beyond pandemic recovery and into a new era of improvement.