I found this document on my daughter's school website. I found it helpful.
http://spectrumrs.weebly.com/uploads/2/2/6/4/22...

The whole medically necessary vs educationally necessary trap is one that schools seem to like to use to confuse parents and deny services. In order for them to change their tune, you need to have documentation showing specific educational goals that won't be met without OT intervention. I wouldn't use the example of not talking before walking because children who have physical disabilities often learn to talk just fine.
Request a meeting in writing and bring in as much documentation as you can. If you show up looking like you have all your evidence collected and could walk right up to a judge with it and make your case, it'll be hard for them to ignore. And you won't need any threats about going to court (which will damage your relationship with the school and should be saved as a last resort only) because it'll be pretty obvious that you're ready for that next step if it comes to it and they won't want that.

Yes do not sign or accept the IEP. The school may say the only have to provide academic services but that is not the case. Schools will try to get away with paying the least amount possible. You have to request another meeting in writing, and they have to comply. Go over the principles head and go to the director of special Ed in your school district and request they be there as well. Make sure when talking to them you tell them you will not accept the IEP or no for an answer, and will have an advocate or even a lawyer there if you have to. Most of the time the threat alone will work, you have to stand up and push back and make them know you are not going away

If your developmental pediatrician or what ever kind of physician who sees your child for the autism puts the request in writing to the school. The school has no choice unless they want to go down the legal road. School receive extra funding for special needs children and that is what those extra funds are for. Be aware that in some states the school can and does bill your insurance company for these services. If the school continues to refuse ask them if there is another school that offers these services that your school can co-op your child to that school. If they are not willing to co-op your child to another school district that has the appropriate services then it may be time to move to a school district that does offer the services. The time it takes to go thru all of the legal mumbo jumbo is lengthy and often leads to bad feelings between the family and the school officials. And lets face it, you can't be at school all the time with your child to know that he/she is not being mis-treated because of all of the legal crap. Trust me the move is worth it. We had a school district that gave my son OT, PT and ST but the rest of the time they only babysat him....they would not apply what the OT, PT, or ST advised them to do....so it was worthless. We bought a $5000 RV and moved it into another district, got a PO Box in that district and during the week we live in that RV so that my son can attend a better school district. It costs me an extra #350 in rental space and electricity per month that I would gladly pay the school district directly but this new school district does not allow transfers from other districts because of over population. Check with the new district...some allow open transfers and you can remain living where you are. The original school district will have to sign off on the transfer but they will sign off rather than having to deal with a legal issue and remind them of that if you have to. My son has been at his new school for 2 years and it has made a huge huge difference in his life. He is so much more independent now than what he ever would have been at the other school.

If you disagree with the district's assessment, you have the legal right to an independent evaluation at district expense by the provider of your choosing.