IDEA is a Federal Regulation. It is applicable to ALL states. Each State agrees to abide by the Fed regs or they don't get federal money. Federal regs supercede state law. There are areas in the Federal Regs that are silent. In these instances, States are allowed to forumulate their own laws. http://www.tea.state.tx.us/ has Texas' side-by-side rules for Special Education. It's a good example of how a state's Special Education laws must parallel the Federal regs.