PP is exactly correct. If there is any doubt that a disability exists, you want the psychologist there. If the disability is clear and the school has already determined eligibility for the 504, you do not need the psychologist there.

Have you had testing done? The psychologist's role is usually to explain the results of any testing (whether the school system did it or you had it done independently). It's hard to know whether to proceed without the psychologist without knowing more about him/her. Do you think there will be an argument over eligibility? Do you think the psychologist will be supportive?

Just wondering what role the school psychologist plays at a 504 meeting, as opposed to the counselor or teacher. School has said we can have meeting on X day without psychologist, or on Y day with the psychologist. WWYD?