If school staff have reason to believe that because of a disability as defined under section 504, a student needs special accommodations or services in the regular classroom in order to participate in the school program, then staff must evaluate the student. This is not necessarily the same as an evaluation for Special Education. Staff may use existing information such as grades, attendance reports, cumulative folder information, observation, and formal or informal test information. Information about current classroom functioning is critical. Parents may provide information from private doctors, therapist, etc.
The student must have an identifiable disability of some sort to qualify for a Section 504 plan. In addition, please be aware that choosing to ignore or not identify a student who needs a 504 plan does not relieve school staff of responsibility to provide access and can result in district and personal legal issues.