We started this process about 2 years ago with my son. We live in the state of Ohio. After finding the State of Ohio policy for gifted students I learned that if referred to the school any student would have to be tested to identify them as gifted. The school has to pay to have this done in OHIO. A student can be referred by a parent, teacher, etc. So we referred him for testing and the school district did an IQ test on him as well as a couple grade level above tests on him to see where he was at. After having these results I was able to know if I should start advocating for more challenging things for him. Last year after a ton of pushing we finally were able to have him subject accelerated in Math. He went to 3rd grade math as a 2nd grader all last school year. It was great but I realized that he still really wasn't getting what he needed in reading. I had originally thought reading was easier to individualize but he really wasn't getting pushed. So about 2 months ago we requested that he be accelerated a full grade level next year. He would skip 3rd grade and go to 4th grade for everything. He had to go through more testing which he never cares about and in fact thinks it is a challenge and is almost excited about it. Our school district is really not open to acceleration or at least the principle at our school. They used the IOWA acceleration form to determine if he should be accelerated but were not complete with filling it out. After an appeal to the superintentent we are just now being told they will allow him to be accelerated.
The best thing I can recommend is do some research on the laws and policies in your state. Find out what they have to do for your child. Know that in many cases you will need to become knowledgeable on options as there are so many road blocks you will probably run into. However, continue to fight for your child if needed so that they too can be challenged in school!
If you have specific questions please feel free to ask!!