Your foster daughter can be claimed on your taxes as a dependent if she meets all the other requirements, but you need her Social Security number. You should reach out to your caseworker from DCS.
Here are all the requirements to claim your child, per What is the Child Tax Credit?
- "Be under age 17 at the end of the tax year
- Is your child, stepchild, foster child, adopted child, sibling, step-sibling, half sibling, or a descendant of any of them (for example, a grandchild, niece, or nephew)
- Has their own Social Security number
- Lived with you for more than half the year
- Didn't support themselves (didn't pay more than half their own expenses)
- Is a U.S. citizen, U.S. national, or U.S. resident alien"
Your 20 year old son is not required to file a federal return, but if any federal income tax was withheld, he can file a return to get a refund. Per the Indiana personal income tax instructions, one must file a return if their income exceeds $1,000 and are single. So, he does need to file an Indiana income tax return. Here is the instruction booklet: IT-40 Full-Year Resident Individual Income Tax Booklet
For more information, see Who Can I Claim as a Tax Dependent?
