As you are married - you have a choice to file a joint tax return or file a s married filing separately.

In most situation - joint tax return will provide you better refund - but you are advised to check both options before finalize the filing status.

The Department of Treasury's Financial Management Service (FMS), which issues IRS tax refunds, has been authorized by Congress to conduct the Treasury Offset Program. Through this program, your refund or overpayment may be reduced by FMS and offset to pay any past-due child support, Federal agency non-tax debts, or state income tax obligations.

If you filed a joint return and you're not responsible for the debt, but you are entitled to a portion of the refund you may request your portion of the refund by filing Form 8379 , Injured Spouse Allocation. Attach Form 8379 to your tax return or file it by itself after you are notified of an offset. If you file a Form 8379 with your return, write "INJURED SPOUSE" at the top left corner of the Form 1040. IRS will process your allocation request before an offset occurs. If you file Form 8379 with your original return, it may take 11 weeks for Electronic Filed returns or up to 14 weeks from the date of filing if you file a paper return, to process your return.

Please be aware - that filing a Form 8379 will provide you with a better refund, but will not eliminate your spouse tax debt. I might suggest that you will contact the IRS and try to establish an installment payment plan.

Let me know if you need any help.

That is your choice - to file a joint tax return or a separate return - you may do either way.

You do not have to file a separate tax returns to protect your part of the refund.

In most situations - filing a joint tax return will provide you with better refund.

But general approach is - to fill both ways and compare refunds.

If you provide more information about your income and deductions - I will help you to estimate - so you will have more knowledge before making a choice.

Let's estimate the income.

Your to-be -a-spouse makes $11.50/hours * 2000 (assumed number of hours worked during the year) = $23,000. Child support has no affect on his taxable income.

You are paid $34,000 annually and will claim one dependent - will be 15 in 2010.

As you likely use standard (not itemized deduction) - I assume that you will the standard deduction in 2010.

You will not be able to claim a head of household filing status (that you likely do now) - and your only choices MFJ or MFS.

These calculations are based on 2009 tax law - so you may expect a little different results for 2010.

If you file jointly - you combined gross income $57,000

taxable income $34650

taxes $4363 minus $1000 child tax credit = $3363 - your refund will be a deference between your withholdings and that amount

If you file separate tax returns

Your income $34000

taxable income $21000

taxes $2733 minus $1000 child tax credit = $1733 - your refund will be a difference between your withholdings and that amount

Your to-be -a-spouse's income $23000

taxable income $13650

taxes $1630 - his refund will be a difference between withholdings and that amount

So compare total tax liability for MFJ - $3363 and for MFS - $1733 + $1630 - there is no any differences. I assume that there will not be any difference or a very small difference in 2010.

I do not have enough information - but most likely - you will not be eligible for saver's credit with either filing status.

Just to compare - if you were not married and you will file as a head of household as you do now:

Your income $34000

taxable income $18350

taxes $2155 minus $1000 child tax credit = $1155 - so you will loose ~$600 - that difference sometimes called "marriage penalty"

Let me know if you need any help.

You should not worry and - please - ask for clarification as you need.

The taxes withheld will be credited to you in any situation.

Thus if you file MFJ and your overall tax liability will be $3363 - considering $4000 withholding - your refund will be $637 -plus $800 Making Work Pay Tax Credit = $1437

plus whatever were withheld from your spouse's paychecks.

If you file as MFS and your overall tax liability will be $1733 - considering $4000 withholding - your estimated refund will be $2237 plus $400 Making Work Pay Tax Credit = $2637

Both refunds in 2010 will likely be a little higher because estimations are made based on 2009 tax laws.

Compare to your current filing as a HOH - you will loose ~$600 plus Savers credit.

Also - you likely pay health insurance and put some money into retirement plan - these should reduce your taxable income and your refund would be a little higher.

Let me know if you need any help.