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When my son was about to turn 5, I was faced with a decision that may be familiar to parents of children whose birthdays are close to kindergarten enrollment cutoff dates.

In my local school district, children must be 5 years old on or ahead of Sept. 1 before they enroll in kindergarten. With a late September birthday, my son was only a few weeks too young to make that cutoff. A friend of mine whose child had a similarly timed birthday was trying for early enrollment. Should I, too?

Ultimately, I decided against it, swallowing thousands of dollars for another year of preschool tuition. Instead of starting kindergarten just a few weeks short of 5, my son started when he was just a few weeks away from turning 6. And while I was not “redshirting” — intentionally holding my child back for a year when he would have otherwise been allowed to enroll — the supposed benefits of redshirting were part of my thinking. Of course, I thought, boys need more time to mature, and starting school on the older end of his cohort would be a clear win.

But are those perceived benefits of redshirting — a term borrowed from athletics and sports eligibility rules — really true? A new study suggests whatever academic boost children may experience when they are the oldest in their kindergarten class fades by the time they reach third grade.

“For the average kid, they’re not going to get that much of an advantage,” said Megan Kuhfeld, the director of growth modeling and data analytics at NWEA, an assessment and research organization behind the Measures of Academic Progress, or MAP, tests used by tens of thousands of schools across the country.

For this analysis, NWEA studied the 3 million students who took the kindergarten through second grade MAP Growth assessment between 2017 and 2025. Researchers also followed a cohort of students who started kindergarten in the 2021-22 school year to see what their test results looked like when they were in third grade, compared to when they entered school.

Students who started kindergarten a year later than their peers had measurable advantages in reading and math. Compared to the average academic growth of kindergartners, the academic advantage by “redshirted” children represented 20 percent to 30 percent of an academic year of learning.

That advantage didn’t last long, however. By the time students entered third grade, children who had been held back a year were indistinguishable from their peers academically.

The NWEA study didn’t dig into the factors behind these findings, but Kuhfeld has some theories. First, there might be some benefit to children to having older peers in the classroom to serve as academic and behavior role models. In other words, children like my son, who started school as an older 5-year-old, could be a positive influence on children who turned 5 shortly before the cutoff for kindergarten enrollment. Children who are already much older than their grade-level peers have no model to emulate.

The benefits of starting school late may also disappear because children who enter school already knowing the kindergarten curriculum may get bored, Kuhfeld said. Classrooms aren’t necessarily set up to push along children who are already meeting academic standards; instead, the teacher is likely to be focused on children who need more help.

Among the more surprising results of the study for me was that redshirting is relatively uncommon. For each of the years studied, about 5 percent of kindergartners started school a year after official eligibility. That peaked at 6.4 percent in fall 2021. The children most likely to be held back a year are white students and boys; redshirting was also more common in low-poverty and rural schools.

Considering how rare the phenomenon is, it sure is talked about a lot. Kuhfeld said that may be because people are more aware of, and worried about, the higher academic demands of kindergarten. Also, Kuhfeld said, the idea of holding children back gained more attention after a prominent author, Richard Reeves, wrote a 2022 article recommending that all boys be redshirted to give them an extra year for their brains to mature. (Rise Together, a fund established by Reeves, is one of the Hechinger Report’s many donors.)

Kuhfeld said that the study focused solely on academics, not behavioral outcomes or other factors, so parents should make decisions that work for their individual children. 

But there are social implications of being older than your grade-level peers, she noted. Parents of kindergartners might not be thinking about this when their children are young, but what does it mean to be the first of your friends to go through puberty, or one of the oldest high school seniors?“It’s worth considering there are trade-offs,” Kuhfeld said. “It’s often painted in conversation as, ‘Of course you would do this,’” she added. “There’s actually a lot of nuance here.”

This story about kindergarten redshirting was produced by The Hechinger Report, a nonprofit, independent news organization focused on inequality and innovation in education. Sign up for the Hechinger newsletter.

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