Is there any downside, to me or the dependent, for claiming a not related adult as a dependent. Is it allowed to take that person as a dependent?

[KatrinaB · Accepted solution]

It would help you to claim any dependents that you are entitled to and it would not affect the dependent since his/her income must be under the filing threshold. However, an unrelated adult must have lived in your home the entire year and have under $4,150 in income (not including social security disability).

Please view the rules for claiming a qualifying relative below:

    Do they live with you? Your relative must live at your residence all year or be on the list of “relatives who do not live with you” in Publication 501. About 30 types of relatives are on this list.
    Do they make less than $4,150 in 2018? Your relative cannot have a gross income of more than $4,150 in 2018 and be claimed by you as a dependent.
    Do you financially support them? You must provide more than half of your relative’s total support each year.
    Are you the only person claiming them? This means you can’t claim the same person twice, once as a qualifying relative and again as a qualifying child. It also means you can’t claim a relative—say a cousin—if someone else, such as his parents, also claim him.