“The school said they would not qualify for an IEP, but they would for a 504 plan.” This is one of the most common statements we hear from parents. Our first question is generally, “Did the district assess?”
504 Plans are not IEPs but are commonly used in schools to provide very limited accommodations. The difference between the two is important to understand.

An Individualized Education Plan (“IEP”) is a plan developed to ensure a child who has a qualifying disability under the Individuals with Disabilities Education Act (“IDEA”) receives an IEP. To develop an IEP, the school must formally assess in all areas of suspected disability, determine eligibility, then develop an IEP. The IEP itself comes with a great deal of procedural safeguards that ideally protect the student and parent. There is also a requirement that students on an IEP have access to their education and make appropriate progress. If a parent disagrees with what the school is doing, they have access to an administrative court to resolve their claims.

A 504 Plan is designed to provide accommodations to students with disabilities. However, it has almost no procedural requirements, does not provide services and is very difficult to enforce. So, if a school decides not to do something in a 504 Plan, there is not a lot a parent can do about it.
The fact is, IEPs are just better.  This is not to say never get a 504 Plan. Instead, at minimum, before you agree to a 504 Plan, make sure the district has conducted comprehensive assessments to determine whether or not your child may qualify for an IEP. If the student does not qualify after they have been assessed, then a 504 Plan may be the right direction. However, too many parents receive 504 Plans without first being assessed for special education.