If your child's birthday falls in June, July, or August, you have probably run the numbers and realized they will be one of the youngest kids in their class, sometimes by nearly a full year. The obvious next question is whether you can just wait in deferring school. In most of the US, you can. Whether you should is a different question, and the research is less flattering to the idea than most parents expect.
Parents sometimes call this deferring, a term used in the UK, where summer-born families can formally request to start a year later. In the US there is no equivalent formal request in most places. Here it is called academic redshirting, borrowed from college sports, and it usually just means not enrolling your child until the following year.
How waiting actually works in the US
The mechanics are simpler than people assume, and they hinge on one fact: kindergarten is not mandatory in many states. Compulsory attendance frequently does not start until a child is 6 or even 7. So if your state sets a cutoff that makes your summer-born child eligible at 5, that is generally permission, not a requirement. You can wait a year without special approval in most districts, though some ask for a form or a conversation.
Waiting a year does not mean your child skips ahead later. Most districts will place a 6-year-old entering school for the first time in kindergarten, not first grade. Families occasionally assume that a year of waiting buys a year of advancement, and it almost never does. If your goal is placement above kindergarten, that is a separate conversation with your district about grade placement and early entrance policies, and the answer is often no.
Two things to confirm before you decide: your state's compulsory attendance age, and your own district's cutoff, since districts can be stricter than state law. Our guide to kindergarten cutoff dates by state has the state-by-state table, and it is the right place to start if you are not sure which side of the line your child falls on.
What the research says
Redshirted children usually do start ahead. They are older, and at 5 an extra year is an enormous share of a life. But studies tracking those children forward find the gap narrowing through first and second grade and largely gone by around third grade. The early advantage is real and mostly temporary.
A subtler finding survives longer: children who are relatively older within their grade, whether or not their family redshirted them, tend to score somewhat higher on tests, with traces still detectable into middle school. That is not quite the same claim, though. It describes a general age-within-grade pattern rather than proving that any individual family's decision to wait produced the result.
And there is a serious caveat running through all of it. This research is correlational. Families who redshirt differ systematically from those who do not, most obviously because delaying school means paying for another year of childcare or having a parent at home. That means some of the measured advantage may belong to family circumstances rather than to the extra year itself. Redshirting is, in practice, more available to families with money, which is worth naming plainly.
The questions that matter more than the birthday
The birth month is a weak signal on its own. Two children born the same July week can be in genuinely different places. So rather than deciding from the calendar, look at the child.
Can they separate from you without prolonged distress? Can they follow a two-step instruction, sit with a task for a stretch, and manage a disagreement with another child without falling apart? Can they handle the physical routine of a full school day, the bathroom, the lunchroom, the noise? Those functional questions predict a decent kindergarten year far better than a birth certificate does. Preschool teachers see this constantly and are usually the most useful people to ask, since they have watched your child alongside dozens of others the same age.
It is also worth weighing what the extra year would actually contain. Another year in a strong preschool with plenty of play and social practice is a real benefit. Another year of unstructured time at home, without much peer contact, is a much weaker case, and for some kids the stimulation of kindergarten is exactly what they need. The alternative matters as much as the delay.
Finally, consider the far end. A redshirted child turns 19 during senior year of high school and hits adolescence noticeably ahead of classmates, which some families see as an advantage in maturity and sports and others see as a mismatch. Neither view is wrong, but it belongs in the decision.
If your child does start on time and turns out to be young for the grade, that is not a crisis, and it is not permanent. Watch how the year goes, stay in contact with the teacher, and know that support exists if they struggle. Our guides on signs a school may not be the right fit and how to tell if a child has a learning disability cover what to watch for when a young student is having a hard time, since being the youngest in the room and having an underlying difficulty can look similar early on and need very different responses.
Sources
NWEA: Kindergarten redshirting, what the research says
Bassok and Reardon, Stanford CEPA: Academic Redshirting in Kindergarten
State and district rules vary; confirm compulsory attendance age and enrollment policy with your own district.
