Can the irs take every penny of my refund for back child support even though I claimed my spouse and her kids as dependents? If yes what form I can file to stop this?

[LaShaunA3]

Yes, if you owe past-due child support, your entire refund can be withheld through the Treasury Offset Program, even if you claim dependents.

However, if part of the refund belongs to your spouse, you can file Form 8379 (Injured Spouse Allocation) to have her portion refunded to her.

[kaylahorst3]

So she was claimed as my dependent, as well as her children so would that still work? 

[SharonD007]

You can't claim your spouse as your dependent.  You have to use the filing status Married Filing Jointly (MFJ) or Married Filing Separately (MFS).  What filing status did you use?

The IRS can seize the entire refund from a married couple's joint tax return even if only one of the spouses was legally liable for the debt. 

Form 8379 is used if a Married Filing Joint couple expects their refund to be intercepted if one of the spouses is legally liable for the debt or filed separately if the injured spouse finds out after the IRS seizes the refund. 

Refer to Form 8379-Injured Spouse and Form 8379 Instructions.

For additional information, refer to the TurboTax article What is IRS Form 8379: Injured Spouse Allocation?