For tax year 2012 we filed jointly and I was the only person earning an income. Based on my wages and taxes paid I was expecting a refund of $4,650 but instead we received a CP42 form stating that $4,361 of that refund was applied to my wife's additional debt from 2010. “===============> As you filed 2012 return as MFJ ; filing a separate return provides relief from joint liability for taxes. By filing a joint tax return, both spouses report all your income, deductions, and credits. Both spouses must sign the return, and both spouses accept full responsibility for the accuracy and completeness of the information reported on the tax return.The IRS cautions, "Both of you may be held responsible, jointly and individually, for the tax and any interest or penalty due on your joint return. One spouse may be held responsible for all the tax due even if all the income was earned by the other spouse" .
“Am I responsible for her tax debt from 2010 even though we filed separately that year?”=========>No in your case as you filed your 2012 return as MFJ; If you file a joint tax return with your spouse and your spouse is liable for a legally enforceable past-due debt, your spouse's creditor, the IRS, in this case, may be able to claim a part or all of your joint tax refund. If you stand to lose part of a tax refund that you are entitled to because of your spouse's debts, you are considered an injured spouse by the IRS. To obtain the portion of your joint tax refund that you are entitled to, you must file Form 8379 with the IRS. You need to answer the questions in Part I and indicate what tax year for which you are filing Form 8379. ALSO indicate whether you are filing a joint return and whether your spouse has a legally enforceable past-due debt. If your answer is no to either of these questions, you do not need to file Form 8379. On question 4, you ned to indicate whether you are legally obligated to pay the past-due debt. On question 5, also indicate whether you are a resident of a community property state. On question 6, indicate whether you personally made and reported estimated tax payments. Indicate whether you received income, have claimed the earned income tax credit or additional child credit or will claim a refundable tax credit.
I do recall that all correspondence from the IRS regarding that debt has been solely addressed to my wife. Should I file a form 8379?”=============>As described above. If all or part of your overpayment was (or is expected to be) applied against your spouse's past-due debt (such as child support), do not file Form 8857. Instead, you need to file Form 8379 to apply to have your share of the overpayment refunded to you.
“ We have lived in VA the entire time, so I don't think community property issues apply.”===========>Correct; VA is not one of the community pty states.