I would recommend that you do file Form 8379, Injured Spouse Allocation. If you do not, the IRS may take the entire refund towards your spouse's debt because you are not asking to get back your portion of the refund. Here are the steps to file Form 8379. Look towards the bottom where it states "What if I've already filed my tax return"
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:
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: