Individuals with Disabilities Education Act (IDEA) is our nation’s special education law. Within IDEA there are disability terms and definitions that guide states on defining disability and determining who is eligible for special education supports. Key elements to the definitions of the federally recognized disability categories are below. Each state determines the specific eligibility criteria. Please refer to your state definitions for more detailed information. It is important to understand that IDEA definitions of disabilities are not the same as medical diagnoses.