Before my youngest started K, I took her in for achievement testing with a private tester. He administered the Woodcock Johnson III and having those results has been a big help in finding a better fit with subject acceleration. He recommended waiting on IQ testing until she turned 6 but the achievement has been enough help so far.
I made an appointment with the principal in the spring before my youngest started K to make a plan. She offered to try a full grade skip but subject acceleration seemed like a better option since there's a gifted magnet that starts in 3rd grade. I didn't have the full report and the brief exit interview seemed good enough. I just gave the principal a one page breakdown with the numbers.
I think the achievement took a couple hours and included writing. I wouldn't try to pack it all in on one day if you also do IQ. Good luck!
