The answer is generally that children enter kindergarten at or around age 5. This means that if your child is four and will turn five within a certain period of time then he/she will be allowed to enter kindergarten. But, if he/she turns five after the specified date then your child will not begin kindergarten until the following year. Most states have very similar protocol, but may differ somewhat. So, as soon as your child turns four you need to begin looking into when your child is old enough to start kindergarten.