Filing separately this year keeps your tax return (income, deductions and refunds) completely separate from your spouse's tax return. The IRS can't offset your refund from a separate return for your spouse's debt.
However, you will probably pay more tax overall by filing separately, because many deductions and credits are reduced or disallowed.
Also, because the tax debt is from a joint return, Pennsylvania could sue you individually or place you in collections, and the "injured" or "innocent" spouse procedures do not apply, because when you signed a joint return, you accepted joint and several liability for all the claims arising from that joint return.
It might be to your advantage to file jointly, claim a larger refund, and use it to pay off the debt sooner rather than later.
