Form 8379, Injured Spouse Allocation is used by a spouse to reclaim their portion of a joint tax refund when the IRS applies the refund to a past-due debt owed solely by the other spouse. These debts can include overdue federal or state taxes, child support, or federal non-tax obligations like student loans.
The "injured spouse" is the one negatively impacted by the refund offset, meaning they do not owe the debt but still lose their share of the refund. Filing Form 8379 allows them to request their rightful portion back. It can be submitted with a joint tax return, an amended return after discovering the refund was seized.