We have ours once a year - ours is in November, and then we have one at year end to update and be ready for the next year. However, there is also an evaluation of the IEP and special services which include the school psychologist. We did that last year, very successfully.
I, as the parent, have a right to call one whenever I feel the need to. I believe they have 30 days to respond and set one up. I def. don't abuse that, although I have used it. Having a good working relationship and full respect of each other is what makes this work best.
And yes, ours is an official meeting. It's usually 1 hour, but can go on a bit longer. The 3 year, however, has consisted of a number of meetings to finalize the writing of the new IEP and eval of services.
The meetings usually include DS' main teacher, the resource teacher, the therapists (OT and speech in DS' case, the psychologist (in the 3 year, but she may join us in the other ones if requested or needed) and the school principal or assistant principal. If another teacher like and art teacher or PE teacher is needed, they can be asked to come, also, but that need hasn't been there for us. I do ask for updates from them once or twice a year, however, and they just seem to understand him, thankfully.
I think I'm going to be talking to the bus garage, too, and helping them get educated a bit. Not as part of this meeting, but separately, and I feel I have the school's backing on it. Mama Bear's on the prowl.
This stuff is SUCH a maze!