here is the accommodation policy for SAT test by college board.
http://www.collegeboard.com/student/testing/sat/reg/ssd.html"Applying for Accommodations
* You must complete a Student Eligibility Form (available from your counselor). If you are requesting accommodations that you receive at your school, your school must also complete part of the form.
* If possible, submit the form in the spring before your first College Board test (PSAT/NMSQT, AP, or SAT) to ensure enough time to process your application.
* If you move to a new school after you have been approved for accommodations, your new school will need to confirm your continued eligibility."
I am not sure where you can get the Student Eligibility Form if your son is home schooled. You may want to call them.