IDEA is a funding statute designed to aid states in meeting the educational needs of students with disabilities. In contrast, Section 504 is a nondiscrimination statute designed to address discriminatory actions (e.g., different treatment, denial of access, disability-based harassment). Section 504 requires that disabled persons be provided equal opportunities as non-disabled persons:
“No otherwise qualified individual with a disability in the United States ... shall, solely by reason of her or his disability, be excluded from participation in, be denied the benefits of, or be subjected to discrimination under any program or activity receiving Federal financial assistance or under any program or activity conducted by any Executive agency or by the United States Postal Service.” 29 U.S.C. § 794(a).
No. Although all students who are eligible for special education under IDEA are also eligible under Section 504, the former has more specific requirements and thus all decisions and documentation regarding identification, evaluation, and placement have to be made pursuant to IDEA requirements.
Yes. See Recommended Evaluation Guidelines here
No. Medication or assistive devices (such as hearing aids, medication, wheelchairs or walkers, etc.) should not be considered in determining whether disability substantially limits a major life activity (e.g., a student with ADHD should be considered as if they had not been taking medication).
Yes. See Discipline section for more on when Manifestation Determination might be needed.