Third-grade proficiency is one of the most consequential milestones in a child’s academic career. Around this time, students transition from learning foundational skills to using those skills to engage with more complex content. This period has become the gateway to state testing, and test scores at that age are highly predictive of later outcomes, including success in high school and graduation.
The question remains whether third grade is uniquely significant or simply the point at which formal measurement first identifies students falling behind. Either way, could testing earlier help improve opportunities to support their academic growth? In recent years, policymakers have increasingly embraced early screening and intervention, particularly around reading, with similar efforts now emerging in early math. Several states use third grade proficiency as a key benchmark, codified through retention policies. But waiting this long to identify struggling students is a questionable choice, as many students have already spent years on trajectories that put them at risk.
NWEA’s Megan Kuhfeld, Karyn Lewis, and Emily Morton set out to understand whether we can reliably identify students who are unlikely to reach proficiency by third grade, and whether those odds change the longer identification is delayed. Using MAP Growth, their organization’s widely used K–12 assessment tool, they tracked over 400,000 students from kindergarten entry in 2021–22 through the spring of third grade, separating the sample into quintiles. That included tracking those who scored in the bottom quintile at each point from fall kindergarten through spring of first grade and comparing their likelihood of eventually reaching third-grade proficiency.[1]
They find that early achievement is a powerful signal but not a determinant. Among students in the bottom quintile at kindergarten entry, 10.3 percent reached math proficiency by third grade. Among students who were still scoring in the lowest group by spring of first grade, only 2.1 percent reached math proficiency by third grade. The implication is that students who remain in the bottom quintile through first grade have a much narrower path to proficiency, which means the opportunity for support is closing well before most school systems intervene today.
Notably, students who started behind were generally more likely to reach proficiency in reading than in math, perhaps because many states have spent the last decade investing in universal reading screening, early literacy interventions, and read-by-grade-three initiatives. Similar policies for early numeracy are far less widespread.
The MAP Growth data may be able to tell us that students who remain in the bottom quintile through first grade rarely reach proficiency by third grade, but it cannot tell us why. Still, the findings suggest the need for more robust assessment and accountability infrastructure beginning in kindergarten. As states are designing their early identification policies around reading, investments in intervention may make a measurable difference. The same logic applies for math and potentially for other core subjects.
The core takeaway is that achievement gaps are visible and significant at kindergarten entry, long before any summative state assessment is administered. While 27 states have kindergarten readiness tools, they vary widely in design and consistency, and screening doesn’t always translate into action. Designing policies that tie interventions to identification helps students and gives parents information to understand their child’s trajectory long before a high-stakes decision arises.
Screening at younger ages gives schools and families valuable information to drive decisions, but that doesn’t do much good unless systems are built to act on it. Policymakers serious about third-grade proficiency would be wise to incorporate kindergarten screening and intervention as the starting point for a coordinated, multi-year response. Waiting even a single school year may narrow the odds that lower-scoring students ever catch up.
SOURCE: Megan Kuhfeld, Karyn Lewis, and Emily Morton, “Behind at the Starting Line: What Kindergarten Test Scores Tell Us About Reaching Proficiency in Third Grade,” NWEA Research (June 2026).
[1] Proficiency represents a higher bar than average achievement. In the MAP Growth data, just over one in three third-graders are considered proficient in reading and math, and students near the middle of the achievement distribution will not reach proficiency without above-average growth.
