In Maryland, they have a testing policy, that if the child is born after Sept 1, but before October 15th (it used to be December 31st), parents can opt to have the kids tested. I don't know what kind of test, nor do I know how they determine if the child is ready for K, BUT I think that every state that has a cutoff should adopt a policy for those with late birthdays. DD4, who will not be attending K until NEXT year turns 5 on October 11th. She would've easily been a Kindergartener this year, and we are not sure of her LOG, if any. Though that still would've left DS6 out until the following year...

http://www.montgomeryschoolsmd.org/departments/earlychi/earlyentranceprocedures.shtm