I agree with SRL.
I don't know about iep's in place already but have had a protracted battle for determination.
They have to accept any and all information that is presented to them. You, your professionals and the staff of the school as well are all
supposed to be equal members of the team.
That doesn't mean that they will agree with the information or allow it to sway their predetermined ideas at a staff meeting. A lot of iep meetings seem to be heavy on school staff and lite on parents and parent support. Though you may have tons of information that seems clear cut they can all "gang up" to speak over you, dismiss your info. and move on to theirs etc. It isn't right but in my experience they make up their minds before a meeting (illegal) and facilitate the meeting to their own end.
When it is my turn I make sure to elaborate on the testing I have because they tend to "accidentally" glaze it over but go into detail with theirs. (convenient) Some of the team may not had read all your results and may only get what small bit is mentioned at the meeting so make sure they get a true feel for what it is otherwise they may never know. At difficult child's school only the psychiatric got our neuropsychologist evaluation. She referred to it in a few sentences but took a few pages to describe her hour session with difficult child.
Said she ran out of room on the form, yeah right!
grrrrrr
I did my best to make sure they followed a nice linear point by point discussion flow. At my difficult child's school they like to jump from topic to topic quickly and leave the parents reeling at the end of the meeting. Then you have to regroup and try to defend your points on so many issues that it all gets confused, comes out jumbled and never amounts to the circles they try to run around you. They give like 5 minutes to discuss parent thoughts after they steam roll 55 minutes on their agenda. So, I make sure they work very very slowly and address each point individually and make sure I get to add my opinion before moving to the next.
They don't like me but I got what I needed to across.