Tax Debt and Divorce
Joint tax returns create joint liability. Divorce doesn't change that, but there are ways to separate it.
If you filed joint tax returns during your marriage, both spouses are fully liable for the entire balance. A divorce decree that assigns the tax debt to one spouse means nothing to the IRS. They can collect from either spouse regardless of what the divorce court ordered.
Innocent Spouse Relief under IRC section 6015 can separate your liability if your former spouse understated income or claimed fraudulent deductions that you didn't know about. There are three forms of relief, and the analysis is fact-intensive.
If you're going through a divorce and there's tax debt involved, or if you're being held responsible for your ex-spouse's tax problems, talk to a tax attorney about separating the liability.