Your boyfriend can not legally claim a child that is not his biological child unless all of these statements are true:
•your child lived in the boyfriend's household for the entire year,
•your boyfriend paid more than half the child's total living expenses (keeping in mind that after counting expenses that are paid by you, the father, other family, or government benefits, the boyfriend must pay more than half of the overall total)
•you (the parent) are not a taxpayer for 2016.
You are not a "taxpayer" if you earned less than $10,350, and you did not file a tax return, or you only filed a tax return to claim a refund of withholding and you claimed no dependents, credits or tax benefits. If you earned more than $10,350, or if you earned less but want to claim EIC or other credits, then you are a taxpayer and you must claim your own child and you can't give the dependent away.
Assuming your boyfriend can legally claim your child, then there is no money to get. Your boyfriend claimed whatever tax benefits were available. If your boyfriend's refund was taken for debt collection, he has to deal with that with whatever agency placed the debt hold on his refund.
Assuming your boyfriend can't legally claim your child as a dependent, you can file a tax return and claim the child as a dependent. You will need to print and mail it in. Your boyfriend will have to file an amended tax return to remove the child and he will owe payback of any refund he got for the child, even though he never got the refund in the first place. (It was taken to pay a debt, if he amends he will owe a new debt to the IRS.) If he doesn't pay, that will just come out of next year's taxes, plus interest and penalties. If you file and claim the child and your boyfriend does not amend, the IRS will send letters and eventually bill him for the difference with interest and penalties.
