Difficult to say without looking at your return.
Credits lost when filing separately include
Earned Income Credit
Education Credits
Child and Dependent Care Credit
If you are claiming the Standard Deduction for both, the Home Mortgage Interest would not be a factor UNLESS you report that your spouse is Itemizing and you are filing separately. In that case, you would be required to itemize also, which might be less than the Standard Deduction.
I suggest you look at the two 1040 to see where the difference is.
Click Tax Home
Click Review if necessary to get Tax Tools on the left side-bar
Click Tax Tools on the left side-bar (you may need to use the scroll bar for the left side-bar to see this)
Click Tools on the drop-down list
Click View Tax Summary on the Tools Center screen
When you do this, Preview my 1040 appears on the left side-bar
Click Preview my 1040 on the left side-bar
TurboTax explains filing separately
**Say "Thanks" by clicking the thumb icon in a post
**Mark the post that answers your question by clicking on "Mark as Best Answer"
