IEPs provide actual service hours from people like special ed teachers, speech therapists, occupational therapists, adapted phy ed teachers, and there are academic goals that are measured and changed periodically. For instance "Student will stay on task 80 percent of the time vs. the 50 percent he is now on task." Or "Student will be able to maintain a back and forth conversation with peer on 2/3 trials." (something like that). With a 504, it's basically just a lit of accommodations and modifications that will be provided to the student. Accommodations and modifications are also in an IEP.
