slf, I think the most important thing to do always, when thinking through what accommodations to ask for, is to look in detail at your child's functioning, where they struggle (if they struggle) with school work etc. You can start with a basic list of accommodations for dysgraphia (you can find this by googling), and it might be helpful to read through your district's policy manual for SPED (or whatever) to see what they list as "typical" accommodations (because these will be accommodations they most likely won't argue against). Also ask the professional who diagnosed your ds for their recommendations. Then look at what you know about your child, and what you think they need to be able to show their knowledge at school.

Our dysgraphic ds has the following accommodations (he's in middle school):

All written work may be completed on a word processor
Extended time on tests (classroom and state testing)
Can write answers in the answer book (rather than filling in bubble sheets)
Oral response on fluency tests (things like timed math facts tests)
Use of a word processor for essay questions on classroom and state testing

Sometimes you can add in instruction into a 504. If your ds doesn't already know how to type, I'd want him to start learning right away, but you might or might not want to ask for help on this through school (for instance, this is something kids can pick up at home, and if instruction at school meant he'd be missing something more important in class when he's pulled out, I wouldn't want to do it through school). You need to think through whether or not your ds has missed out on any writing skills development due to undiagnosed dysgraphia, and you might want to have him get instruction on those (this would probably be more in line with requesting an IEP... which you might want to consider). Dysgraphics spend so much time thinking about how to write the physical letters they don't have working memory to devote to thinking about puncuation/grammar/content... so my concern here is has your ds missed out on learning skills for written expression that the other kids are picking up on because he's been having to expend extra effort just to produce writing? If you have any concerns about this, I'd suggest you ask the school to administer the TOWL (Test of Written Language) - this is a very widely available and widely recognized test that shows where a student has gaps in written expression skills.

FWIW, our ds uses some software that is helpful - it's not specifically outlined in his official list of accommodations, but it might be worth checking into (word prediction, voice-to-text are two that our ds finds most useful). He also has software that allows him to graph and write formulas for math.

His official accommodations list uses the term "word processor" to be generic, but fwiw - over the years he's used an AlphaSmart, a laptop and now uses and iPad. It's been very important that the device he uses is portable (not a classroom computer sitting in a corner away from the teacher and other students). There are also issues to consider when using a laptop/etc - how to print, how to turn in assignments etc (our ds turns in his assignments via email most of the time).

That's all I can think of at the moment - if you have additional or specific questions, ask!

polarbear