I have a great nephew that has resided with me the whole year of 2016, the parents are divorced and agree to me filing him as a dependent on my return; can I do this?

[unsureaunt]

If so, do I file head of household and do I list as son, foster child, etc?  Do I need a signed agreement from the parents?

[bwa · Accepted solution]

He would be a dependent and would be treated as your own son.  List him as "other", then as a nephew (a great nephew is treated the same.)  You need no agreement from the parents.