Illinois Kindergarten Age Cutoff: The September 1 Rule

In Illinois, a child can start public kindergarten if they turn 5 years old on or before September 1 of that school year. A child who turns 5 on September 2 or later usually waits until the following year.

The rule comes from the Illinois School Code (105 ILCS 5/10-20.12), and every public school district in the state uses the same date. What districts can decide is whether to offer early entrance for children with fall birthdays. Here is how it all works.

The Illinois kindergarten cutoff, with examples

For the 2027-28 school year, which starts in August 2027:

• A child born on September 1, 2022 turns 5 on September 1, 2027 and can start kindergarten in fall 2027.
• A child born on September 2, 2022 turns 5 one day after the cutoff and would normally start in fall 2028.
• A child born in August 2022 can start in fall 2027 and will be one of the youngest in the class.

The same rule applies to first grade: a child should be 6 on or before September 1. There is one exception in state law. A child who finished kindergarten with a licensed teacher and turns 6 by December 31 may be allowed into first grade.

Is kindergarten mandatory in Illinois?

No. Illinois law requires children to attend school from age 6 (turning 6 on or before September 1) until age 17. Kindergarten is not required, and a child does not have to finish kindergarten before enrolling in first grade.

Every public school district must offer kindergarten, though, and nearly all families use it. Lawmakers have proposed lowering the compulsory age to 5 several times, but as of late 2026 those bills have not become law.

One detail many parents miss: once a five-year-old is enrolled in a public kindergarten, the family is expected to keep the child attending like any other student. Enrolling is optional. Skipping days after enrolling is not.

Early entrance for children with fall birthdays

If your child turns 5 shortly after September 1 and seems ready, ask your district about early entrance. Illinois allows districts to admit younger children based on an individual assessment, and many districts handle this through their accelerated placement policy.

How it usually works:

• Parents apply in winter or early spring, often between February and March, for the fall start.
• The child is assessed for academic and social readiness, usually by the district.
• Some districts only consider children who turn 5 within a few weeks of the cutoff, such as by September 30.
• Decisions are made by a district team and are often final.

Rules and deadlines vary a lot from one district to the next. Some districts rarely approve early entrance. Check your district's website or call the registration office in January.

Should you start your child early, on time or a year later?

Children with summer birthdays, especially June through August, are the youngest in the class. Some families choose to wait a year before kindergarten, which is often called redshirting. Since kindergarten is not mandatory in Illinois, waiting until a child is 6 is allowed.

There is no single right answer. Things worth weighing:

• How your child handles separation, group instructions and a full school day
• Whether they can take care of basic needs, like using the bathroom and putting on a coat
• What their preschool or pre-K teacher sees in the classroom
• Whether they would spend the extra year in a quality pre-K program or at home
• Your local district's approach, since some districts discourage holding children back

Talk with your child's current teacher before deciding. They see your child in a group setting every day, which is exactly what kindergarten will be.

Full-day kindergarten is coming to every district

A state law signed in 2023 requires every Illinois public school district to offer full-day kindergarten by the 2027-28 school year. Districts that cannot meet the deadline can request a waiver of up to two more years. If your district only offers half-day kindergarten now, ask whether it plans to switch and when.

Full-day kindergarten still usually ends around 3:00 PM, and the school calendar includes breaks and days off. Working parents typically need before and after school care, plus care for school holidays and summer.

Key dates for kindergarten registration

Most suburban Chicago districts open kindergarten registration between January and March for the fall. Chicago Public Schools uses its own application process. You will usually need:

• Your child's birth certificate
• Proof that you live in the district, such as a lease or utility bill
• Immunization records and a recent physical exam
• A dental exam and, for new students, an eye exam, which Illinois requires for kindergarten

Start gathering records in the fall before your child starts. Doctor and dentist appointments fill up quickly in spring and summer.

Frequently asked questions

What is the kindergarten age cutoff in Illinois?

A child must be 5 on or before September 1 of the school year to enroll in public kindergarten.

Can my child start kindergarten at 4 in Illinois?

Only through early entrance, if your district offers it and your child passes its readiness assessment. Most children who start at 4 have birthdays within a few weeks after September 1.

Is kindergarten required in Illinois?

No. School attendance is required starting at age 6. Kindergarten is optional, but every public district must offer it.

Can my child go straight to first grade at 6?

Yes. A child who is 6 by September 1 can enroll in first grade without having attended kindergarten. Many schools will still assess the child to choose the right placement.

Getting ready for kindergarten at Children's Land

Children's Land offers a pre-K program for four-year-olds and a private kindergarten for five and six-year-olds, with a 1 to 10 teacher-to-child ratio and MAP testing twice a year. Both run inside a full 7:00 AM to 6:00 PM day, so you do not need separate before and after care. Learn more about our private kindergarten or find a location near you.

Related reading: Preparing Preschoolers for Kindergarten: A Parent’s Checklist.