At age 9, with stimulants not working and focus still an issue... I'd be pushing for him to be tested for Auditory Processing Disorders (APD) - specifically, auditory figure ground and auditory distinction. These can "look like" ADD in the classroom.
He complains about not being able to remember stuff, although he's a demon on his tablets and never forgets a thing. We go on hikes and he'll tell me all the stuff he remembers about the plants we talked about, the birds we saw, where that lizard was, etc. He's an amazing reader and he does remember what he reads. It's math, worksheets, classroom work, etc. that is hard for him. He's so oppositional to any demands. "No" is always the first thing out of his mouth. If I ignore it and go on about my business, he'll do what is asked on his own most of the time, although he may cry, rub his eyes, and be crabby about it. At school, that's harder, although his teacher, the angel that she is, is trying to give him options and keep him calm. But, she has 30 obstreperous 4th grader, half of whom are boys. I would be poking my eyes out with sharp pencils!
His father, on the other hand, will take his "No" and make a huge power struggle out of it and then it's on. Police even got called once. And his father threatens to take him to the hospital when he acts out. Needless to say, he is refusing any and all contact with him and I can tell it's on his mind and causing stress and anxiety. It's hard to sort out the emotional stuff from the brain difference stuff, although he's always had social problems, even has a toddler.
He does like having his own quiet space in the classroom that his teacher set up for him. When he gets close to other kids, he has a hard time keeping his hands to himself and gets in a lot of trouble for that. As for that testing, does an Occupational Therapist (OT) do it? We can't get squat out of Kaiser. We've tried asking for school-based Occupational Therapist (OT) for his horrible handwriting, but they say it isn't interfering with his schoolwork. Uh, he can't write well, it's a huge effort for him, so he won't do it. I think he will be a wicked good keyboarder someday, so that's good. If we can get him through the next few years until the schools want typed work.
Good suggestion, InsaneCdn. I work with OTs and I'll try to get a few minutes with one of them and ask.
I don't know the pathway in the US. Here, the first would be an intense screening by a Speech Language Pathologist (SLP). We couldn't get it through the school (they didn't believe he had a problem), so we paid out-of-pocket and it was reasonable. Based on the Speech Language Pathologist (SLP) report, the family doctor referred to the advanced (PhD level) audiologist for complete testing.