We provided all of his support for the entire 2017 and 4 full months of 2018. We also spent a lot of travel time and support taking him to medical appointments, between 2 or 3 a week until he passed.
I'm sorry for your loss. Yes, you can absolutely claim him. You need to say that he lived with your all year in the program. You don't mention his age or if he had a job at any point in 2018. If he was under 19, or under 24 and a full time student, he is considered a child. If he was older than 18 and not in school, he would have had to earn less than $4,150.