You may be an injured spouse if you file a joint tax return and all or part of your portion of the overpayment was, or is expected to be, applied (offset) to your spouse’s legally enforceable past-due federal tax, state income tax, child or spousal support, or a federal nontax debt, such as a student loan. You can file form 8379 by itself separately and after you filed your return.

To file an injured spouse go to
Federal Taxes or Personal (for H&B/Self Employed version)
Other Tax Situations
Other Tax Forms
Miscellaneous Tax Forms - click the Start or Update button
7th item, Report an injured or innocent spouse claim