There are two different forms that get confused.
Form 8379 Injured Spouse is used when your tax refund from a joint return is taken to satisfy a past debt incurred by your spouse before the marriage. Injured spouse applies to debts that are owed only by your spouse.
Form 8857 Innocent Spouse is used when you are being held responsible for a tax bill from a joint return with your spouse, when you argue that only your spouse should be responsible. You must first understand that when you file a joint return, both spouses take full responsibility for the reported income, deductions and tax. If that joint return is later found to be in error, or fraudulent, both spouses are responsible. The Innocent Spouse form is used when you want to claim that your spouse alone is responsible for the error and the tax. Usually, you must be divorced or separated to file for Innocent Spouse relief. Innocent spouse relief only applies to joint debts from past joint returns, and does not apply to past debts owed by one spouse.
The Turbotax interview is designed to direct you to the correct form, and to disallow incorrect claims (to reduce the number of nuisance and invalid claims the IRS has to process). If Turbotax tells you that you don't qualify, then you either misunderstand the correct form to use, or you may not qualify due to the facts and circumstances.
You can file either form by downloading the paperwork from the IRS directly, but carefully read the instructions and make sure you have a valid claim.
https://www.irs.gov/uac/about-form-8857
https://www.irs.gov/uac/form-8379-injured-spouse-allocation
