Kamesa Carter As someone who was introduced to the Logans at age 8 by my elementary school librarian, I've always considered the series as middle grade/YA. I would consider this book YA as well. While the characters are now adults (appealing to those who grew up reading the series like I did) I would still consider it YA for its handling of racial issues and relationships, but also for its lack of explicit sex and violence. There's no swearing, but be advised that the n-word is used throughout the novel due to the time period it takes place in. As a teacher and a parent, I have no problem allowing middle/high school students reading this.
Christine I think it would, or at least I would consider it a cross over novel--appealing to both high schoolers and adults. I think it's considered a YA book precisely for the reason you mentioned--it's part of a series that, initially, appealed to children. To be clear, there is no reason children couldn't read this. There is very little in the way of swearing and sex. But it does have disturbing imagery in it as it accurately chronicles what Black people endured at the hands of white people in the 1940s - 1960s.