Depending on the circumstances, you may be eligible for innocent spouse relief. You can be relieved of responsibility for paying tax, interest, and penalties if your spouse (or former spouse) improperly reported items or omitted items on your tax return. Generally, the tax, interest, and penalties that qualify for relief can only be collected from your spouse (or former spouse) if awarded this relief.
There are several factors the IRS considers including whether you knew about the debt or had reason to know, whether you benefited from the extra money not reported, whether there was abuse or a pattern of abuse or control, whether you are divorced or separated, whether it would be equitable to provide relief.
Applying for relief appears as simple as filling out tax form 8857 or as complicated as filing a tax court petition. The record you provide, however, is extremely important. Make sure you know your rights before you apply.