We have a subject acceleration in math. Reading seems more difficult, and I agree that it would be helpful only if other pieces were in place, such as strong writing ability, etc. In my child's class I would say that there are a solid half dozen who are very well ahead of grade level reading--by several years. It really seems like reading levels are all over the place in the early years. Most of the kids just read their novels during reading time. Can you move up the ladder a bit in asking for differentiation?