He will still be paying child support through July of 2020, so 7 months of the year. I don’t think we’d be in the wrong having him claim him that year (in fact, the court docs have him claiming him for 2020 anyhow).
After that, I’m not sure. It’s always been kind of fuzzy to me because in order to claim someone as a dependent you’re supposed to provide more than half their support, but what if they’re getting a lot of money in grants, and scholarships and taking student loans? There are a couple schools DS could attend where he could pretty much cover all his costs. I guess they’re home summers and breaks…