Autistic Kids Struggle With Handwriting

what kind of therapies should be sought out for this problem? My son will be 15 next week and still struggles with his handwriting. We've been in all types of therapy for autism but I've never seen an OT that dealt with handwriting. Is this something we can ask for in a school IEP?

My son get's O.T for this issue. It would be something to request an eval for fromt he O.T at school, using examples of those 5 things of this study. Of the 5 things tested within this study, my son has issues with all 5. It's not just a fine motor thing, for some kids it's muscle tone/ hand stregnth and or visual processing.
What we do for my son is use a high lighter, instead of relying on lined paper. We high light with green the length of where he is to write, it gives him the visual of where to write small, along with verbal reminders about spacing and also his lettering touching thecorrect area's. Some people use raised lines within the paper.

It's a matter of finding what works best for the child. Some children need pencil grips, and they come in different shapes and styles.

Our OT (private not school related) recommended a program named "Hand Writing Without Tears", special pencil grips and starting with a much shorter than normal pencil to learn proper holding techniques.