IEP VS 504

[Cure4CF]

So my daughters school wants to change her from an IEP to a 504. She has had the IEP and is in second grade going to third next year. Just checking to see if anybody has any experience with the difference. From what I have read and researched the 504 should be fine. My big concern is if something happens down the road that we would need to switch back to the IEP, it's going to be a lot harder. She is very smart, she is in second grade reads at a sixth grade level math is at a fourth grade level, it's more about taking medicines, missing school because of getting sick, etc. Thanks in advance!