My oldest son was so disorganized he even came home with one shoe one time! Don't ask. Anyway, he did not have an IEP or 504 but each year we met with the teachers and respectfully requested that they give a discreet reminder at the end of class and/or required him to show them that he had written down assignments. Most teachers were willing to help and then we checked after school. This cut down greatly on missed assignments but did not entirely eliminate them. Often the papers were "lost" between school and home. FWIW he is now a successful junior in a large university and somehow, now that no one else is responsible or there to blame except him, he manages to get it all done. Sometimes natural consequences work best it seems. I have another disorganized son entering 4th grade. So far there is minimal homework so no big issue but I am sure I will be struggling again. Good luck!