Hi -I don't have a satisfactory answer to your question, but I'll pipe in anyway. In many states the school districts decide who is eligible for gifted services, so it will differ quite a bit from school district to school district, and state to state.
Here's a quote from the MN Dept of Education site: "Minnesota is a local control state, which allows districts to select the method for identifying students who would qualify for Gifted and Talented services."
I know of a few districts around here that require 130 IQ to qualify for early entrance to kindergarten, but since I don't have a child in school yet, i'm not familiar with any other cutoffs.
