Children who are biologically related to you (children, grandchildren, nieces, nephews, grandnieces and grandnephews, younger siblings) don't have to be placed by a court. All other children (unrelated or more distantly related) must be placed in your home by a court.
Then, you can claim the children as qualifying child dependents if they lived in your home more than half the nights of the year, and did not provide more than half their own support, and were under age 19 or were full time students under age 24. (For newborns, they must live in your home more than half the nights since their birth.)
If they did not live in your home more than half the nights of the year, they can't be qualifying child dependents but could be qualifying relative dependents if you provided more than 50% of their total support. If you provided less than 50% of their total support for the year, you might be able to claim them if you get a signed agreement from everyone who provided more than 10% of their support agreeing that you will claim them and they won't.
