What would be the tax benefit of adding an adult (23 yo male) that lives with us and we financially support. They do not have a job and not going to school.

If you can claim your 23 year old as a qualifying relative you get then-refundable $500 credit for other dependents.  

Qualifying relative

• They don't have to be related to you (despite the name).
• They aren't claimed as a dependent by someone else.
• They're a U.S. citizen, resident alien, national, or a Canadian or Mexican resident.
• They aren’t filing a joint return with their spouse.
• They lived with you the entire year (exceptions apply).
• They made less than $5050 in 2024.   (Not counting Social Security)
• You provided more than half of their financial support.

When you add someone as a dependent, we'll ask a series of questions to make sure you can claim them. There may be other tax benefits you can get when you claim a dependent.

Related Information:

• What does "financially support another person" mean?

If you claim a dependent as a qualified relative, you will get the Other dependent credit of $500.

The person has to satisfy all the following tests:

1. The person can't be your qualifying child or the qualifying child of any other taxpayer. 
2. The person must live with you  all year as a member of your household (and your relationship must not violate local laws). 
3. The person's gross income for the year 2024 must be less than $5,050. 
4. You must provide more than half of the person's total support for the year.
5. The person is a U.S. citizen, U.S. resident alien, U.S. national.
6. The person is not a married person who files a joint return unless that joint return is filed only to claim a refund of withheld income tax or estimated tax paid.