Please see the NOTE below about clicking through several pages of Form 8857 before getting to Form 8379.
The Injured Spouse
Form is filed when the overpayment on your jointly filed tax return was (or is
expected to be) applied to a past-due obligation of your spouse. Here is a TurboTax FAQ with the steps:
https://ttlc.intuit.com/replies/3326788
NOTE: You will need to click through several pages of Innocent Spouse
questions before you get to the Injured Spouse section.
If you are filing the Injured Spouse Form on its own
(after e-filing your return), you will mail it to the IRS location for
your state. Include a copy of all W-2 forms and any 1099 forms
showing federal tax withholding, for both spouses. You can find the
mailing address for your location using this link (use the 'not including a
payment' address): https://www.irs.gov/uac/where-to-file-paper-tax-returns-with-or-without-a-payment
See more information below from the IRS:
IRS-Seven
Facts about Injured Spouse Relief
