You've received great advice already. I'll just add a question - Would the test results be part of the data and information entered into the
Iowa Acceleration Scale (
IAS) for parent(s) & school team to discuss acceleration?
The IAS has places to record IQ and achievement test results. School-administered individual IQ tests, CogAT (Cognitive Abilities Test), WJ-ACH (Woodcock-Johnson Tests of Achievement) and an above-grade-level ITBS (Iowa Test of Basic Skills) are among the tests mentioned. As these scores are just a few of the many factors considered for a grade skip, and as the school is already familiar with your child, I agree with ConnectingDots that requesting end-of-grade-level tests may provide meaningful alternative scores for considering a grade skip.
If interested in the Explore test, you may wish to look at the website of the
Duke TIP academic talent search, to consider registering your son for the Explore test. The current list of Test Center Locations does not show any in New York, however several locations are shown for Pennsylvania.
Meanwhile, have you read the threads on
possible downside or trade-offs to grade skipping. This is not to dissuade you or cause you to second-guess the decision, but to remain prepared for the differences this may make in your child's journey.