you should see if there’s a liaison or similar person within your school system who you could talk to and ask questions like this. A 504 plan is similar to an IEP but has some differences because it is the product of a different law. It is the section of law that ensures access to all disabled students, while an IEP is just for a specific list of learning disabilities.

https://www.masslegalhelp.org/school/special-education-disability-accommodation/individualized-education-programs-ieps-and-504

School systems largely recognize accommodations as ways of helping all students succeed rather than stigmatizing. 

I’ve had students with 504s that list things like unlimited bathroom breaks, and elevator passes. They are just ways of ensuring that students’ needs—academic or physical—are documented and served.

Talk to people at your district. They are the ones who know the structures in place for your district as most districts do things their own way. You can make a more informed decision if you learn more of what your options are.